sqlglot.generator

   1from __future__ import annotations
   2
   3import logging
   4import typing as t
   5from collections import defaultdict
   6from functools import reduce
   7
   8from sqlglot import exp
   9from sqlglot.errors import ErrorLevel, UnsupportedError, concat_messages
  10from sqlglot.helper import apply_index_offset, csv, seq_get
  11from sqlglot.time import format_time
  12from sqlglot.tokens import Tokenizer, TokenType
  13
  14if t.TYPE_CHECKING:
  15    from sqlglot._typing import E
  16
  17logger = logging.getLogger("sqlglot")
  18
  19
  20class Generator:
  21    """
  22    Generator converts a given syntax tree to the corresponding SQL string.
  23
  24    Args:
  25        pretty: Whether or not to format the produced SQL string.
  26            Default: False.
  27        identify: Determines when an identifier should be quoted. Possible values are:
  28            False (default): Never quote, except in cases where it's mandatory by the dialect.
  29            True or 'always': Always quote.
  30            'safe': Only quote identifiers that are case insensitive.
  31        normalize: Whether or not to normalize identifiers to lowercase.
  32            Default: False.
  33        pad: Determines the pad size in a formatted string.
  34            Default: 2.
  35        indent: Determines the indentation size in a formatted string.
  36            Default: 2.
  37        normalize_functions: Whether or not to normalize all function names. Possible values are:
  38            "upper" or True (default): Convert names to uppercase.
  39            "lower": Convert names to lowercase.
  40            False: Disables function name normalization.
  41        unsupported_level: Determines the generator's behavior when it encounters unsupported expressions.
  42            Default ErrorLevel.WARN.
  43        max_unsupported: Maximum number of unsupported messages to include in a raised UnsupportedError.
  44            This is only relevant if unsupported_level is ErrorLevel.RAISE.
  45            Default: 3
  46        leading_comma: Determines whether or not the comma is leading or trailing in select expressions.
  47            This is only relevant when generating in pretty mode.
  48            Default: False
  49        max_text_width: The max number of characters in a segment before creating new lines in pretty mode.
  50            The default is on the smaller end because the length only represents a segment and not the true
  51            line length.
  52            Default: 80
  53        comments: Whether or not to preserve comments in the output SQL code.
  54            Default: True
  55    """
  56
  57    TRANSFORMS = {
  58        exp.DateAdd: lambda self, e: self.func(
  59            "DATE_ADD", e.this, e.expression, exp.Literal.string(e.text("unit"))
  60        ),
  61        exp.TsOrDsAdd: lambda self, e: self.func(
  62            "TS_OR_DS_ADD", e.this, e.expression, exp.Literal.string(e.text("unit"))
  63        ),
  64        exp.CaseSpecificColumnConstraint: lambda self, e: f"{'NOT ' if e.args.get('not_') else ''}CASESPECIFIC",
  65        exp.CharacterSetColumnConstraint: lambda self, e: f"CHARACTER SET {self.sql(e, 'this')}",
  66        exp.CharacterSetProperty: lambda self, e: f"{'DEFAULT ' if e.args.get('default') else ''}CHARACTER SET={self.sql(e, 'this')}",
  67        exp.CheckColumnConstraint: lambda self, e: f"CHECK ({self.sql(e, 'this')})",
  68        exp.ClusteredColumnConstraint: lambda self, e: f"CLUSTERED ({self.expressions(e, 'this', indent=False)})",
  69        exp.CollateColumnConstraint: lambda self, e: f"COLLATE {self.sql(e, 'this')}",
  70        exp.CopyGrantsProperty: lambda self, e: "COPY GRANTS",
  71        exp.CommentColumnConstraint: lambda self, e: f"COMMENT {self.sql(e, 'this')}",
  72        exp.DateFormatColumnConstraint: lambda self, e: f"FORMAT {self.sql(e, 'this')}",
  73        exp.DefaultColumnConstraint: lambda self, e: f"DEFAULT {self.sql(e, 'this')}",
  74        exp.EncodeColumnConstraint: lambda self, e: f"ENCODE {self.sql(e, 'this')}",
  75        exp.ExecuteAsProperty: lambda self, e: self.naked_property(e),
  76        exp.ExternalProperty: lambda self, e: "EXTERNAL",
  77        exp.HeapProperty: lambda self, e: "HEAP",
  78        exp.InlineLengthColumnConstraint: lambda self, e: f"INLINE LENGTH {self.sql(e, 'this')}",
  79        exp.InputModelProperty: lambda self, e: f"INPUT{self.sql(e, 'this')}",
  80        exp.IntervalSpan: lambda self, e: f"{self.sql(e, 'this')} TO {self.sql(e, 'expression')}",
  81        exp.LanguageProperty: lambda self, e: self.naked_property(e),
  82        exp.LocationProperty: lambda self, e: self.naked_property(e),
  83        exp.LogProperty: lambda self, e: f"{'NO ' if e.args.get('no') else ''}LOG",
  84        exp.MaterializedProperty: lambda self, e: "MATERIALIZED",
  85        exp.NoPrimaryIndexProperty: lambda self, e: "NO PRIMARY INDEX",
  86        exp.NonClusteredColumnConstraint: lambda self, e: f"NONCLUSTERED ({self.expressions(e, 'this', indent=False)})",
  87        exp.NotForReplicationColumnConstraint: lambda self, e: "NOT FOR REPLICATION",
  88        exp.OnCommitProperty: lambda self, e: f"ON COMMIT {'DELETE' if e.args.get('delete') else 'PRESERVE'} ROWS",
  89        exp.OnProperty: lambda self, e: f"ON {self.sql(e, 'this')}",
  90        exp.OnUpdateColumnConstraint: lambda self, e: f"ON UPDATE {self.sql(e, 'this')}",
  91        exp.OutputModelProperty: lambda self, e: f"OUTPUT{self.sql(e, 'this')}",
  92        exp.PathColumnConstraint: lambda self, e: f"PATH {self.sql(e, 'this')}",
  93        exp.RemoteWithConnectionModelProperty: lambda self, e: f"REMOTE WITH CONNECTION {self.sql(e, 'this')}",
  94        exp.ReturnsProperty: lambda self, e: self.naked_property(e),
  95        exp.SampleProperty: lambda self, e: f"SAMPLE BY {self.sql(e, 'this')}",
  96        exp.SetProperty: lambda self, e: f"{'MULTI' if e.args.get('multi') else ''}SET",
  97        exp.SettingsProperty: lambda self, e: f"SETTINGS{self.seg('')}{(self.expressions(e))}",
  98        exp.SqlSecurityProperty: lambda self, e: f"SQL SECURITY {'DEFINER' if e.args.get('definer') else 'INVOKER'}",
  99        exp.StabilityProperty: lambda self, e: e.name,
 100        exp.TemporaryProperty: lambda self, e: f"TEMPORARY",
 101        exp.ToTableProperty: lambda self, e: f"TO {self.sql(e.this)}",
 102        exp.TransientProperty: lambda self, e: "TRANSIENT",
 103        exp.TransformModelProperty: lambda self, e: self.func("TRANSFORM", *e.expressions),
 104        exp.TitleColumnConstraint: lambda self, e: f"TITLE {self.sql(e, 'this')}",
 105        exp.UppercaseColumnConstraint: lambda self, e: f"UPPERCASE",
 106        exp.VarMap: lambda self, e: self.func("MAP", e.args["keys"], e.args["values"]),
 107        exp.VolatileProperty: lambda self, e: "VOLATILE",
 108        exp.WithJournalTableProperty: lambda self, e: f"WITH JOURNAL TABLE={self.sql(e, 'this')}",
 109    }
 110
 111    # Whether the base comes first
 112    LOG_BASE_FIRST = True
 113
 114    # Whether or not null ordering is supported in order by
 115    NULL_ORDERING_SUPPORTED = True
 116
 117    # Whether or not locking reads (i.e. SELECT ... FOR UPDATE/SHARE) are supported
 118    LOCKING_READS_SUPPORTED = False
 119
 120    # Always do union distinct or union all
 121    EXPLICIT_UNION = False
 122
 123    # Wrap derived values in parens, usually standard but spark doesn't support it
 124    WRAP_DERIVED_VALUES = True
 125
 126    # Whether or not create function uses an AS before the RETURN
 127    CREATE_FUNCTION_RETURN_AS = True
 128
 129    # Whether or not MERGE ... WHEN MATCHED BY SOURCE is allowed
 130    MATCHED_BY_SOURCE = True
 131
 132    # Whether or not the INTERVAL expression works only with values like '1 day'
 133    SINGLE_STRING_INTERVAL = False
 134
 135    # Whether or not the plural form of date parts like day (i.e. "days") is supported in INTERVALs
 136    INTERVAL_ALLOWS_PLURAL_FORM = True
 137
 138    # Whether or not the TABLESAMPLE clause supports a method name, like BERNOULLI
 139    TABLESAMPLE_WITH_METHOD = True
 140
 141    # Whether or not to treat the number in TABLESAMPLE (50) as a percentage
 142    TABLESAMPLE_SIZE_IS_PERCENT = False
 143
 144    # Whether or not limit and fetch are supported (possible values: "ALL", "LIMIT", "FETCH")
 145    LIMIT_FETCH = "ALL"
 146
 147    # Whether or not limit and fetch allows expresions or just limits
 148    LIMIT_ONLY_LITERALS = False
 149
 150    # Whether or not a table is allowed to be renamed with a db
 151    RENAME_TABLE_WITH_DB = True
 152
 153    # The separator for grouping sets and rollups
 154    GROUPINGS_SEP = ","
 155
 156    # The string used for creating an index on a table
 157    INDEX_ON = "ON"
 158
 159    # Whether or not join hints should be generated
 160    JOIN_HINTS = True
 161
 162    # Whether or not table hints should be generated
 163    TABLE_HINTS = True
 164
 165    # Whether or not query hints should be generated
 166    QUERY_HINTS = True
 167
 168    # What kind of separator to use for query hints
 169    QUERY_HINT_SEP = ", "
 170
 171    # Whether or not comparing against booleans (e.g. x IS TRUE) is supported
 172    IS_BOOL_ALLOWED = True
 173
 174    # Whether or not to include the "SET" keyword in the "INSERT ... ON DUPLICATE KEY UPDATE" statement
 175    DUPLICATE_KEY_UPDATE_WITH_SET = True
 176
 177    # Whether or not to generate the limit as TOP <value> instead of LIMIT <value>
 178    LIMIT_IS_TOP = False
 179
 180    # Whether or not to generate INSERT INTO ... RETURNING or INSERT INTO RETURNING ...
 181    RETURNING_END = True
 182
 183    # Whether or not to generate the (+) suffix for columns used in old-style join conditions
 184    COLUMN_JOIN_MARKS_SUPPORTED = False
 185
 186    # Whether or not to generate an unquoted value for EXTRACT's date part argument
 187    EXTRACT_ALLOWS_QUOTES = True
 188
 189    # Whether or not TIMETZ / TIMESTAMPTZ will be generated using the "WITH TIME ZONE" syntax
 190    TZ_TO_WITH_TIME_ZONE = False
 191
 192    # Whether or not the NVL2 function is supported
 193    NVL2_SUPPORTED = True
 194
 195    # https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax
 196    SELECT_KINDS: t.Tuple[str, ...] = ("STRUCT", "VALUE")
 197
 198    # Whether or not VALUES statements can be used as derived tables.
 199    # MySQL 5 and Redshift do not allow this, so when False, it will convert
 200    # SELECT * VALUES into SELECT UNION
 201    VALUES_AS_TABLE = True
 202
 203    # Whether or not the word COLUMN is included when adding a column with ALTER TABLE
 204    ALTER_TABLE_ADD_COLUMN_KEYWORD = True
 205
 206    # UNNEST WITH ORDINALITY (presto) instead of UNNEST WITH OFFSET (bigquery)
 207    UNNEST_WITH_ORDINALITY = True
 208
 209    # Whether or not FILTER (WHERE cond) can be used for conditional aggregation
 210    AGGREGATE_FILTER_SUPPORTED = True
 211
 212    # Whether or not JOIN sides (LEFT, RIGHT) are supported in conjunction with SEMI/ANTI join kinds
 213    SEMI_ANTI_JOIN_WITH_SIDE = True
 214
 215    # Whether or not session variables / parameters are supported, e.g. @x in T-SQL
 216    SUPPORTS_PARAMETERS = True
 217
 218    # Whether or not to include the type of a computed column in the CREATE DDL
 219    COMPUTED_COLUMN_WITH_TYPE = True
 220
 221    # Whether or not CREATE TABLE .. COPY .. is supported. False means we'll generate CLONE instead of COPY
 222    SUPPORTS_TABLE_COPY = True
 223
 224    # Whether or not parentheses are required around the table sample's expression
 225    TABLESAMPLE_REQUIRES_PARENS = True
 226
 227    # Whether or not COLLATE is a function instead of a binary operator
 228    COLLATE_IS_FUNC = False
 229
 230    # Whether or not data types support additional specifiers like e.g. CHAR or BYTE (oracle)
 231    DATA_TYPE_SPECIFIERS_ALLOWED = False
 232
 233    TYPE_MAPPING = {
 234        exp.DataType.Type.NCHAR: "CHAR",
 235        exp.DataType.Type.NVARCHAR: "VARCHAR",
 236        exp.DataType.Type.MEDIUMTEXT: "TEXT",
 237        exp.DataType.Type.LONGTEXT: "TEXT",
 238        exp.DataType.Type.TINYTEXT: "TEXT",
 239        exp.DataType.Type.MEDIUMBLOB: "BLOB",
 240        exp.DataType.Type.LONGBLOB: "BLOB",
 241        exp.DataType.Type.TINYBLOB: "BLOB",
 242        exp.DataType.Type.INET: "INET",
 243    }
 244
 245    STAR_MAPPING = {
 246        "except": "EXCEPT",
 247        "replace": "REPLACE",
 248    }
 249
 250    TIME_PART_SINGULARS = {
 251        "microseconds": "microsecond",
 252        "seconds": "second",
 253        "minutes": "minute",
 254        "hours": "hour",
 255        "days": "day",
 256        "weeks": "week",
 257        "months": "month",
 258        "quarters": "quarter",
 259        "years": "year",
 260    }
 261
 262    TOKEN_MAPPING: t.Dict[TokenType, str] = {}
 263
 264    STRUCT_DELIMITER = ("<", ">")
 265
 266    PARAMETER_TOKEN = "@"
 267
 268    PROPERTIES_LOCATION = {
 269        exp.AlgorithmProperty: exp.Properties.Location.POST_CREATE,
 270        exp.AutoIncrementProperty: exp.Properties.Location.POST_SCHEMA,
 271        exp.BlockCompressionProperty: exp.Properties.Location.POST_NAME,
 272        exp.CharacterSetProperty: exp.Properties.Location.POST_SCHEMA,
 273        exp.ChecksumProperty: exp.Properties.Location.POST_NAME,
 274        exp.CollateProperty: exp.Properties.Location.POST_SCHEMA,
 275        exp.CopyGrantsProperty: exp.Properties.Location.POST_SCHEMA,
 276        exp.Cluster: exp.Properties.Location.POST_SCHEMA,
 277        exp.ClusteredByProperty: exp.Properties.Location.POST_SCHEMA,
 278        exp.DataBlocksizeProperty: exp.Properties.Location.POST_NAME,
 279        exp.DefinerProperty: exp.Properties.Location.POST_CREATE,
 280        exp.DictRange: exp.Properties.Location.POST_SCHEMA,
 281        exp.DictProperty: exp.Properties.Location.POST_SCHEMA,
 282        exp.DistKeyProperty: exp.Properties.Location.POST_SCHEMA,
 283        exp.DistStyleProperty: exp.Properties.Location.POST_SCHEMA,
 284        exp.EngineProperty: exp.Properties.Location.POST_SCHEMA,
 285        exp.ExecuteAsProperty: exp.Properties.Location.POST_SCHEMA,
 286        exp.ExternalProperty: exp.Properties.Location.POST_CREATE,
 287        exp.FallbackProperty: exp.Properties.Location.POST_NAME,
 288        exp.FileFormatProperty: exp.Properties.Location.POST_WITH,
 289        exp.FreespaceProperty: exp.Properties.Location.POST_NAME,
 290        exp.HeapProperty: exp.Properties.Location.POST_WITH,
 291        exp.InputModelProperty: exp.Properties.Location.POST_SCHEMA,
 292        exp.IsolatedLoadingProperty: exp.Properties.Location.POST_NAME,
 293        exp.JournalProperty: exp.Properties.Location.POST_NAME,
 294        exp.LanguageProperty: exp.Properties.Location.POST_SCHEMA,
 295        exp.LikeProperty: exp.Properties.Location.POST_SCHEMA,
 296        exp.LocationProperty: exp.Properties.Location.POST_SCHEMA,
 297        exp.LockingProperty: exp.Properties.Location.POST_ALIAS,
 298        exp.LogProperty: exp.Properties.Location.POST_NAME,
 299        exp.MaterializedProperty: exp.Properties.Location.POST_CREATE,
 300        exp.MergeBlockRatioProperty: exp.Properties.Location.POST_NAME,
 301        exp.NoPrimaryIndexProperty: exp.Properties.Location.POST_EXPRESSION,
 302        exp.OnProperty: exp.Properties.Location.POST_SCHEMA,
 303        exp.OnCommitProperty: exp.Properties.Location.POST_EXPRESSION,
 304        exp.Order: exp.Properties.Location.POST_SCHEMA,
 305        exp.OutputModelProperty: exp.Properties.Location.POST_SCHEMA,
 306        exp.PartitionedByProperty: exp.Properties.Location.POST_WITH,
 307        exp.PrimaryKey: exp.Properties.Location.POST_SCHEMA,
 308        exp.Property: exp.Properties.Location.POST_WITH,
 309        exp.RemoteWithConnectionModelProperty: exp.Properties.Location.POST_SCHEMA,
 310        exp.ReturnsProperty: exp.Properties.Location.POST_SCHEMA,
 311        exp.RowFormatProperty: exp.Properties.Location.POST_SCHEMA,
 312        exp.RowFormatDelimitedProperty: exp.Properties.Location.POST_SCHEMA,
 313        exp.RowFormatSerdeProperty: exp.Properties.Location.POST_SCHEMA,
 314        exp.SampleProperty: exp.Properties.Location.POST_SCHEMA,
 315        exp.SchemaCommentProperty: exp.Properties.Location.POST_SCHEMA,
 316        exp.SerdeProperties: exp.Properties.Location.POST_SCHEMA,
 317        exp.Set: exp.Properties.Location.POST_SCHEMA,
 318        exp.SettingsProperty: exp.Properties.Location.POST_SCHEMA,
 319        exp.SetProperty: exp.Properties.Location.POST_CREATE,
 320        exp.SortKeyProperty: exp.Properties.Location.POST_SCHEMA,
 321        exp.SqlSecurityProperty: exp.Properties.Location.POST_CREATE,
 322        exp.StabilityProperty: exp.Properties.Location.POST_SCHEMA,
 323        exp.TemporaryProperty: exp.Properties.Location.POST_CREATE,
 324        exp.ToTableProperty: exp.Properties.Location.POST_SCHEMA,
 325        exp.TransientProperty: exp.Properties.Location.POST_CREATE,
 326        exp.TransformModelProperty: exp.Properties.Location.POST_SCHEMA,
 327        exp.MergeTreeTTL: exp.Properties.Location.POST_SCHEMA,
 328        exp.VolatileProperty: exp.Properties.Location.POST_CREATE,
 329        exp.WithDataProperty: exp.Properties.Location.POST_EXPRESSION,
 330        exp.WithJournalTableProperty: exp.Properties.Location.POST_NAME,
 331    }
 332
 333    # Keywords that can't be used as unquoted identifier names
 334    RESERVED_KEYWORDS: t.Set[str] = set()
 335
 336    # Expressions whose comments are separated from them for better formatting
 337    WITH_SEPARATED_COMMENTS: t.Tuple[t.Type[exp.Expression], ...] = (
 338        exp.Create,
 339        exp.Delete,
 340        exp.Drop,
 341        exp.From,
 342        exp.Insert,
 343        exp.Join,
 344        exp.Select,
 345        exp.Update,
 346        exp.Where,
 347        exp.With,
 348    )
 349
 350    # Expressions that should not have their comments generated in maybe_comment
 351    EXCLUDE_COMMENTS: t.Tuple[t.Type[exp.Expression], ...] = (
 352        exp.Binary,
 353        exp.Union,
 354    )
 355
 356    # Expressions that can remain unwrapped when appearing in the context of an INTERVAL
 357    UNWRAPPED_INTERVAL_VALUES: t.Tuple[t.Type[exp.Expression], ...] = (
 358        exp.Column,
 359        exp.Literal,
 360        exp.Neg,
 361        exp.Paren,
 362    )
 363
 364    SENTINEL_LINE_BREAK = "__SQLGLOT__LB__"
 365
 366    # Autofilled
 367    INVERSE_TIME_MAPPING: t.Dict[str, str] = {}
 368    INVERSE_TIME_TRIE: t.Dict = {}
 369    INVERSE_ESCAPE_SEQUENCES: t.Dict[str, str] = {}
 370    INDEX_OFFSET = 0
 371    UNNEST_COLUMN_ONLY = False
 372    ALIAS_POST_TABLESAMPLE = False
 373    IDENTIFIERS_CAN_START_WITH_DIGIT = False
 374    STRICT_STRING_CONCAT = False
 375    NORMALIZE_FUNCTIONS: bool | str = "upper"
 376    NULL_ORDERING = "nulls_are_small"
 377
 378    can_identify: t.Callable[[str, str | bool], bool]
 379
 380    # Delimiters for quotes, identifiers and the corresponding escape characters
 381    QUOTE_START = "'"
 382    QUOTE_END = "'"
 383    IDENTIFIER_START = '"'
 384    IDENTIFIER_END = '"'
 385    TOKENIZER_CLASS = Tokenizer
 386
 387    # Delimiters for bit, hex, byte and raw literals
 388    BIT_START: t.Optional[str] = None
 389    BIT_END: t.Optional[str] = None
 390    HEX_START: t.Optional[str] = None
 391    HEX_END: t.Optional[str] = None
 392    BYTE_START: t.Optional[str] = None
 393    BYTE_END: t.Optional[str] = None
 394
 395    __slots__ = (
 396        "pretty",
 397        "identify",
 398        "normalize",
 399        "pad",
 400        "_indent",
 401        "normalize_functions",
 402        "unsupported_level",
 403        "max_unsupported",
 404        "leading_comma",
 405        "max_text_width",
 406        "comments",
 407        "unsupported_messages",
 408        "_escaped_quote_end",
 409        "_escaped_identifier_end",
 410        "_cache",
 411    )
 412
 413    def __init__(
 414        self,
 415        pretty: t.Optional[bool] = None,
 416        identify: str | bool = False,
 417        normalize: bool = False,
 418        pad: int = 2,
 419        indent: int = 2,
 420        normalize_functions: t.Optional[str | bool] = None,
 421        unsupported_level: ErrorLevel = ErrorLevel.WARN,
 422        max_unsupported: int = 3,
 423        leading_comma: bool = False,
 424        max_text_width: int = 80,
 425        comments: bool = True,
 426    ):
 427        import sqlglot
 428
 429        self.pretty = pretty if pretty is not None else sqlglot.pretty
 430        self.identify = identify
 431        self.normalize = normalize
 432        self.pad = pad
 433        self._indent = indent
 434        self.unsupported_level = unsupported_level
 435        self.max_unsupported = max_unsupported
 436        self.leading_comma = leading_comma
 437        self.max_text_width = max_text_width
 438        self.comments = comments
 439
 440        # This is both a Dialect property and a Generator argument, so we prioritize the latter
 441        self.normalize_functions = (
 442            self.NORMALIZE_FUNCTIONS if normalize_functions is None else normalize_functions
 443        )
 444
 445        self.unsupported_messages: t.List[str] = []
 446        self._escaped_quote_end: str = self.TOKENIZER_CLASS.STRING_ESCAPES[0] + self.QUOTE_END
 447        self._escaped_identifier_end: str = (
 448            self.TOKENIZER_CLASS.IDENTIFIER_ESCAPES[0] + self.IDENTIFIER_END
 449        )
 450        self._cache: t.Optional[t.Dict[int, str]] = None
 451
 452    def generate(
 453        self,
 454        expression: t.Optional[exp.Expression],
 455        cache: t.Optional[t.Dict[int, str]] = None,
 456    ) -> str:
 457        """
 458        Generates the SQL string corresponding to the given syntax tree.
 459
 460        Args:
 461            expression: The syntax tree.
 462            cache: An optional sql string cache. This leverages the hash of an Expression
 463                which can be slow to compute, so only use it if you set _hash on each node.
 464
 465        Returns:
 466            The SQL string corresponding to `expression`.
 467        """
 468        if cache is not None:
 469            self._cache = cache
 470
 471        self.unsupported_messages = []
 472        sql = self.sql(expression).strip()
 473        self._cache = None
 474
 475        if self.unsupported_level == ErrorLevel.IGNORE:
 476            return sql
 477
 478        if self.unsupported_level == ErrorLevel.WARN:
 479            for msg in self.unsupported_messages:
 480                logger.warning(msg)
 481        elif self.unsupported_level == ErrorLevel.RAISE and self.unsupported_messages:
 482            raise UnsupportedError(concat_messages(self.unsupported_messages, self.max_unsupported))
 483
 484        if self.pretty:
 485            sql = sql.replace(self.SENTINEL_LINE_BREAK, "\n")
 486        return sql
 487
 488    def unsupported(self, message: str) -> None:
 489        if self.unsupported_level == ErrorLevel.IMMEDIATE:
 490            raise UnsupportedError(message)
 491        self.unsupported_messages.append(message)
 492
 493    def sep(self, sep: str = " ") -> str:
 494        return f"{sep.strip()}\n" if self.pretty else sep
 495
 496    def seg(self, sql: str, sep: str = " ") -> str:
 497        return f"{self.sep(sep)}{sql}"
 498
 499    def pad_comment(self, comment: str) -> str:
 500        comment = " " + comment if comment[0].strip() else comment
 501        comment = comment + " " if comment[-1].strip() else comment
 502        return comment
 503
 504    def maybe_comment(
 505        self,
 506        sql: str,
 507        expression: t.Optional[exp.Expression] = None,
 508        comments: t.Optional[t.List[str]] = None,
 509    ) -> str:
 510        comments = (
 511            ((expression and expression.comments) if comments is None else comments)  # type: ignore
 512            if self.comments
 513            else None
 514        )
 515
 516        if not comments or isinstance(expression, self.EXCLUDE_COMMENTS):
 517            return sql
 518
 519        comments_sql = " ".join(
 520            f"/*{self.pad_comment(comment)}*/" for comment in comments if comment
 521        )
 522
 523        if not comments_sql:
 524            return sql
 525
 526        if isinstance(expression, self.WITH_SEPARATED_COMMENTS):
 527            return (
 528                f"{self.sep()}{comments_sql}{sql}"
 529                if sql[0].isspace()
 530                else f"{comments_sql}{self.sep()}{sql}"
 531            )
 532
 533        return f"{sql} {comments_sql}"
 534
 535    def wrap(self, expression: exp.Expression | str) -> str:
 536        this_sql = self.indent(
 537            self.sql(expression)
 538            if isinstance(expression, (exp.Select, exp.Union))
 539            else self.sql(expression, "this"),
 540            level=1,
 541            pad=0,
 542        )
 543        return f"({self.sep('')}{this_sql}{self.seg(')', sep='')}"
 544
 545    def no_identify(self, func: t.Callable[..., str], *args, **kwargs) -> str:
 546        original = self.identify
 547        self.identify = False
 548        result = func(*args, **kwargs)
 549        self.identify = original
 550        return result
 551
 552    def normalize_func(self, name: str) -> str:
 553        if self.normalize_functions == "upper" or self.normalize_functions is True:
 554            return name.upper()
 555        if self.normalize_functions == "lower":
 556            return name.lower()
 557        return name
 558
 559    def indent(
 560        self,
 561        sql: str,
 562        level: int = 0,
 563        pad: t.Optional[int] = None,
 564        skip_first: bool = False,
 565        skip_last: bool = False,
 566    ) -> str:
 567        if not self.pretty:
 568            return sql
 569
 570        pad = self.pad if pad is None else pad
 571        lines = sql.split("\n")
 572
 573        return "\n".join(
 574            line
 575            if (skip_first and i == 0) or (skip_last and i == len(lines) - 1)
 576            else f"{' ' * (level * self._indent + pad)}{line}"
 577            for i, line in enumerate(lines)
 578        )
 579
 580    def sql(
 581        self,
 582        expression: t.Optional[str | exp.Expression],
 583        key: t.Optional[str] = None,
 584        comment: bool = True,
 585    ) -> str:
 586        if not expression:
 587            return ""
 588
 589        if isinstance(expression, str):
 590            return expression
 591
 592        if key:
 593            value = expression.args.get(key)
 594            if value:
 595                return self.sql(value)
 596            return ""
 597
 598        if self._cache is not None:
 599            expression_id = hash(expression)
 600
 601            if expression_id in self._cache:
 602                return self._cache[expression_id]
 603
 604        transform = self.TRANSFORMS.get(expression.__class__)
 605
 606        if callable(transform):
 607            sql = transform(self, expression)
 608        elif transform:
 609            sql = transform
 610        elif isinstance(expression, exp.Expression):
 611            exp_handler_name = f"{expression.key}_sql"
 612
 613            if hasattr(self, exp_handler_name):
 614                sql = getattr(self, exp_handler_name)(expression)
 615            elif isinstance(expression, exp.Func):
 616                sql = self.function_fallback_sql(expression)
 617            elif isinstance(expression, exp.Property):
 618                sql = self.property_sql(expression)
 619            else:
 620                raise ValueError(f"Unsupported expression type {expression.__class__.__name__}")
 621        else:
 622            raise ValueError(f"Expected an Expression. Received {type(expression)}: {expression}")
 623
 624        sql = self.maybe_comment(sql, expression) if self.comments and comment else sql
 625
 626        if self._cache is not None:
 627            self._cache[expression_id] = sql
 628        return sql
 629
 630    def uncache_sql(self, expression: exp.Uncache) -> str:
 631        table = self.sql(expression, "this")
 632        exists_sql = " IF EXISTS" if expression.args.get("exists") else ""
 633        return f"UNCACHE TABLE{exists_sql} {table}"
 634
 635    def cache_sql(self, expression: exp.Cache) -> str:
 636        lazy = " LAZY" if expression.args.get("lazy") else ""
 637        table = self.sql(expression, "this")
 638        options = expression.args.get("options")
 639        options = f" OPTIONS({self.sql(options[0])} = {self.sql(options[1])})" if options else ""
 640        sql = self.sql(expression, "expression")
 641        sql = f" AS{self.sep()}{sql}" if sql else ""
 642        sql = f"CACHE{lazy} TABLE {table}{options}{sql}"
 643        return self.prepend_ctes(expression, sql)
 644
 645    def characterset_sql(self, expression: exp.CharacterSet) -> str:
 646        if isinstance(expression.parent, exp.Cast):
 647            return f"CHAR CHARACTER SET {self.sql(expression, 'this')}"
 648        default = "DEFAULT " if expression.args.get("default") else ""
 649        return f"{default}CHARACTER SET={self.sql(expression, 'this')}"
 650
 651    def column_sql(self, expression: exp.Column) -> str:
 652        join_mark = " (+)" if expression.args.get("join_mark") else ""
 653
 654        if join_mark and not self.COLUMN_JOIN_MARKS_SUPPORTED:
 655            join_mark = ""
 656            self.unsupported("Outer join syntax using the (+) operator is not supported.")
 657
 658        column = ".".join(
 659            self.sql(part)
 660            for part in (
 661                expression.args.get("catalog"),
 662                expression.args.get("db"),
 663                expression.args.get("table"),
 664                expression.args.get("this"),
 665            )
 666            if part
 667        )
 668
 669        return f"{column}{join_mark}"
 670
 671    def columnposition_sql(self, expression: exp.ColumnPosition) -> str:
 672        this = self.sql(expression, "this")
 673        this = f" {this}" if this else ""
 674        position = self.sql(expression, "position")
 675        return f"{position}{this}"
 676
 677    def columndef_sql(self, expression: exp.ColumnDef, sep: str = " ") -> str:
 678        column = self.sql(expression, "this")
 679        kind = self.sql(expression, "kind")
 680        constraints = self.expressions(expression, key="constraints", sep=" ", flat=True)
 681        exists = "IF NOT EXISTS " if expression.args.get("exists") else ""
 682        kind = f"{sep}{kind}" if kind else ""
 683        constraints = f" {constraints}" if constraints else ""
 684        position = self.sql(expression, "position")
 685        position = f" {position}" if position else ""
 686
 687        if expression.find(exp.ComputedColumnConstraint) and not self.COMPUTED_COLUMN_WITH_TYPE:
 688            kind = ""
 689
 690        return f"{exists}{column}{kind}{constraints}{position}"
 691
 692    def columnconstraint_sql(self, expression: exp.ColumnConstraint) -> str:
 693        this = self.sql(expression, "this")
 694        kind_sql = self.sql(expression, "kind").strip()
 695        return f"CONSTRAINT {this} {kind_sql}" if this else kind_sql
 696
 697    def computedcolumnconstraint_sql(self, expression: exp.ComputedColumnConstraint) -> str:
 698        this = self.sql(expression, "this")
 699        if expression.args.get("not_null"):
 700            persisted = " PERSISTED NOT NULL"
 701        elif expression.args.get("persisted"):
 702            persisted = " PERSISTED"
 703        else:
 704            persisted = ""
 705        return f"AS {this}{persisted}"
 706
 707    def autoincrementcolumnconstraint_sql(self, _) -> str:
 708        return self.token_sql(TokenType.AUTO_INCREMENT)
 709
 710    def compresscolumnconstraint_sql(self, expression: exp.CompressColumnConstraint) -> str:
 711        if isinstance(expression.this, list):
 712            this = self.wrap(self.expressions(expression, key="this", flat=True))
 713        else:
 714            this = self.sql(expression, "this")
 715
 716        return f"COMPRESS {this}"
 717
 718    def generatedasidentitycolumnconstraint_sql(
 719        self, expression: exp.GeneratedAsIdentityColumnConstraint
 720    ) -> str:
 721        this = ""
 722        if expression.this is not None:
 723            on_null = " ON NULL" if expression.args.get("on_null") else ""
 724            this = " ALWAYS" if expression.this else f" BY DEFAULT{on_null}"
 725
 726        start = expression.args.get("start")
 727        start = f"START WITH {start}" if start else ""
 728        increment = expression.args.get("increment")
 729        increment = f" INCREMENT BY {increment}" if increment else ""
 730        minvalue = expression.args.get("minvalue")
 731        minvalue = f" MINVALUE {minvalue}" if minvalue else ""
 732        maxvalue = expression.args.get("maxvalue")
 733        maxvalue = f" MAXVALUE {maxvalue}" if maxvalue else ""
 734        cycle = expression.args.get("cycle")
 735        cycle_sql = ""
 736
 737        if cycle is not None:
 738            cycle_sql = f"{' NO' if not cycle else ''} CYCLE"
 739            cycle_sql = cycle_sql.strip() if not start and not increment else cycle_sql
 740
 741        sequence_opts = ""
 742        if start or increment or cycle_sql:
 743            sequence_opts = f"{start}{increment}{minvalue}{maxvalue}{cycle_sql}"
 744            sequence_opts = f" ({sequence_opts.strip()})"
 745
 746        expr = self.sql(expression, "expression")
 747        expr = f"({expr})" if expr else "IDENTITY"
 748
 749        return f"GENERATED{this} AS {expr}{sequence_opts}"
 750
 751    def notnullcolumnconstraint_sql(self, expression: exp.NotNullColumnConstraint) -> str:
 752        return f"{'' if expression.args.get('allow_null') else 'NOT '}NULL"
 753
 754    def primarykeycolumnconstraint_sql(self, expression: exp.PrimaryKeyColumnConstraint) -> str:
 755        desc = expression.args.get("desc")
 756        if desc is not None:
 757            return f"PRIMARY KEY{' DESC' if desc else ' ASC'}"
 758        return f"PRIMARY KEY"
 759
 760    def uniquecolumnconstraint_sql(self, expression: exp.UniqueColumnConstraint) -> str:
 761        this = self.sql(expression, "this")
 762        this = f" {this}" if this else ""
 763        index_type = expression.args.get("index_type")
 764        index_type = f" USING {index_type}" if index_type else ""
 765        return f"UNIQUE{this}{index_type}"
 766
 767    def createable_sql(self, expression: exp.Create, locations: t.DefaultDict) -> str:
 768        return self.sql(expression, "this")
 769
 770    def create_sql(self, expression: exp.Create) -> str:
 771        kind = self.sql(expression, "kind").upper()
 772        properties = expression.args.get("properties")
 773        properties_locs = self.locate_properties(properties) if properties else defaultdict()
 774
 775        this = self.createable_sql(expression, properties_locs)
 776
 777        properties_sql = ""
 778        if properties_locs.get(exp.Properties.Location.POST_SCHEMA) or properties_locs.get(
 779            exp.Properties.Location.POST_WITH
 780        ):
 781            properties_sql = self.sql(
 782                exp.Properties(
 783                    expressions=[
 784                        *properties_locs[exp.Properties.Location.POST_SCHEMA],
 785                        *properties_locs[exp.Properties.Location.POST_WITH],
 786                    ]
 787                )
 788            )
 789
 790        begin = " BEGIN" if expression.args.get("begin") else ""
 791        end = " END" if expression.args.get("end") else ""
 792
 793        expression_sql = self.sql(expression, "expression")
 794        if expression_sql:
 795            expression_sql = f"{begin}{self.sep()}{expression_sql}{end}"
 796
 797            if self.CREATE_FUNCTION_RETURN_AS or not isinstance(expression.expression, exp.Return):
 798                if properties_locs.get(exp.Properties.Location.POST_ALIAS):
 799                    postalias_props_sql = self.properties(
 800                        exp.Properties(
 801                            expressions=properties_locs[exp.Properties.Location.POST_ALIAS]
 802                        ),
 803                        wrapped=False,
 804                    )
 805                    expression_sql = f" AS {postalias_props_sql}{expression_sql}"
 806                else:
 807                    expression_sql = f" AS{expression_sql}"
 808
 809        postindex_props_sql = ""
 810        if properties_locs.get(exp.Properties.Location.POST_INDEX):
 811            postindex_props_sql = self.properties(
 812                exp.Properties(expressions=properties_locs[exp.Properties.Location.POST_INDEX]),
 813                wrapped=False,
 814                prefix=" ",
 815            )
 816
 817        indexes = self.expressions(expression, key="indexes", indent=False, sep=" ")
 818        indexes = f" {indexes}" if indexes else ""
 819        index_sql = indexes + postindex_props_sql
 820
 821        replace = " OR REPLACE" if expression.args.get("replace") else ""
 822        unique = " UNIQUE" if expression.args.get("unique") else ""
 823
 824        postcreate_props_sql = ""
 825        if properties_locs.get(exp.Properties.Location.POST_CREATE):
 826            postcreate_props_sql = self.properties(
 827                exp.Properties(expressions=properties_locs[exp.Properties.Location.POST_CREATE]),
 828                sep=" ",
 829                prefix=" ",
 830                wrapped=False,
 831            )
 832
 833        modifiers = "".join((replace, unique, postcreate_props_sql))
 834
 835        postexpression_props_sql = ""
 836        if properties_locs.get(exp.Properties.Location.POST_EXPRESSION):
 837            postexpression_props_sql = self.properties(
 838                exp.Properties(
 839                    expressions=properties_locs[exp.Properties.Location.POST_EXPRESSION]
 840                ),
 841                sep=" ",
 842                prefix=" ",
 843                wrapped=False,
 844            )
 845
 846        exists_sql = " IF NOT EXISTS" if expression.args.get("exists") else ""
 847        no_schema_binding = (
 848            " WITH NO SCHEMA BINDING" if expression.args.get("no_schema_binding") else ""
 849        )
 850
 851        clone = self.sql(expression, "clone")
 852        clone = f" {clone}" if clone else ""
 853
 854        expression_sql = f"CREATE{modifiers} {kind}{exists_sql} {this}{properties_sql}{expression_sql}{postexpression_props_sql}{index_sql}{no_schema_binding}{clone}"
 855        return self.prepend_ctes(expression, expression_sql)
 856
 857    def clone_sql(self, expression: exp.Clone) -> str:
 858        this = self.sql(expression, "this")
 859        shallow = "SHALLOW " if expression.args.get("shallow") else ""
 860        keyword = "COPY" if expression.args.get("copy") and self.SUPPORTS_TABLE_COPY else "CLONE"
 861        this = f"{shallow}{keyword} {this}"
 862        when = self.sql(expression, "when")
 863
 864        if when:
 865            kind = self.sql(expression, "kind")
 866            expr = self.sql(expression, "expression")
 867            return f"{this} {when} ({kind} => {expr})"
 868
 869        return this
 870
 871    def describe_sql(self, expression: exp.Describe) -> str:
 872        return f"DESCRIBE {self.sql(expression, 'this')}"
 873
 874    def prepend_ctes(self, expression: exp.Expression, sql: str) -> str:
 875        with_ = self.sql(expression, "with")
 876        if with_:
 877            sql = f"{with_}{self.sep()}{sql}"
 878        return sql
 879
 880    def with_sql(self, expression: exp.With) -> str:
 881        sql = self.expressions(expression, flat=True)
 882        recursive = "RECURSIVE " if expression.args.get("recursive") else ""
 883
 884        return f"WITH {recursive}{sql}"
 885
 886    def cte_sql(self, expression: exp.CTE) -> str:
 887        alias = self.sql(expression, "alias")
 888        return f"{alias} AS {self.wrap(expression)}"
 889
 890    def tablealias_sql(self, expression: exp.TableAlias) -> str:
 891        alias = self.sql(expression, "this")
 892        columns = self.expressions(expression, key="columns", flat=True)
 893        columns = f"({columns})" if columns else ""
 894        return f"{alias}{columns}"
 895
 896    def bitstring_sql(self, expression: exp.BitString) -> str:
 897        this = self.sql(expression, "this")
 898        if self.BIT_START:
 899            return f"{self.BIT_START}{this}{self.BIT_END}"
 900        return f"{int(this, 2)}"
 901
 902    def hexstring_sql(self, expression: exp.HexString) -> str:
 903        this = self.sql(expression, "this")
 904        if self.HEX_START:
 905            return f"{self.HEX_START}{this}{self.HEX_END}"
 906        return f"{int(this, 16)}"
 907
 908    def bytestring_sql(self, expression: exp.ByteString) -> str:
 909        this = self.sql(expression, "this")
 910        if self.BYTE_START:
 911            return f"{self.BYTE_START}{this}{self.BYTE_END}"
 912        return this
 913
 914    def rawstring_sql(self, expression: exp.RawString) -> str:
 915        string = self.escape_str(expression.this.replace("\\", "\\\\"))
 916        return f"{self.QUOTE_START}{string}{self.QUOTE_END}"
 917
 918    def datatypeparam_sql(self, expression: exp.DataTypeParam) -> str:
 919        this = self.sql(expression, "this")
 920        specifier = self.sql(expression, "expression")
 921        specifier = f" {specifier}" if specifier and self.DATA_TYPE_SPECIFIERS_ALLOWED else ""
 922        return f"{this}{specifier}"
 923
 924    def datatype_sql(self, expression: exp.DataType) -> str:
 925        type_value = expression.this
 926
 927        if type_value == exp.DataType.Type.USERDEFINED and expression.args.get("kind"):
 928            type_sql = self.sql(expression, "kind")
 929        else:
 930            type_sql = (
 931                self.TYPE_MAPPING.get(type_value, type_value.value)
 932                if isinstance(type_value, exp.DataType.Type)
 933                else type_value
 934            )
 935
 936        nested = ""
 937        interior = self.expressions(expression, flat=True)
 938        values = ""
 939
 940        if interior:
 941            if expression.args.get("nested"):
 942                nested = f"{self.STRUCT_DELIMITER[0]}{interior}{self.STRUCT_DELIMITER[1]}"
 943                if expression.args.get("values") is not None:
 944                    delimiters = ("[", "]") if type_value == exp.DataType.Type.ARRAY else ("(", ")")
 945                    values = self.expressions(expression, key="values", flat=True)
 946                    values = f"{delimiters[0]}{values}{delimiters[1]}"
 947            elif type_value == exp.DataType.Type.INTERVAL:
 948                nested = f" {interior}"
 949            else:
 950                nested = f"({interior})"
 951
 952        type_sql = f"{type_sql}{nested}{values}"
 953        if self.TZ_TO_WITH_TIME_ZONE and type_value in (
 954            exp.DataType.Type.TIMETZ,
 955            exp.DataType.Type.TIMESTAMPTZ,
 956        ):
 957            type_sql = f"{type_sql} WITH TIME ZONE"
 958
 959        return type_sql
 960
 961    def directory_sql(self, expression: exp.Directory) -> str:
 962        local = "LOCAL " if expression.args.get("local") else ""
 963        row_format = self.sql(expression, "row_format")
 964        row_format = f" {row_format}" if row_format else ""
 965        return f"{local}DIRECTORY {self.sql(expression, 'this')}{row_format}"
 966
 967    def delete_sql(self, expression: exp.Delete) -> str:
 968        this = self.sql(expression, "this")
 969        this = f" FROM {this}" if this else ""
 970        using = self.sql(expression, "using")
 971        using = f" USING {using}" if using else ""
 972        where = self.sql(expression, "where")
 973        returning = self.sql(expression, "returning")
 974        limit = self.sql(expression, "limit")
 975        tables = self.expressions(expression, key="tables")
 976        tables = f" {tables}" if tables else ""
 977        if self.RETURNING_END:
 978            expression_sql = f"{this}{using}{where}{returning}{limit}"
 979        else:
 980            expression_sql = f"{returning}{this}{using}{where}{limit}"
 981        return self.prepend_ctes(expression, f"DELETE{tables}{expression_sql}")
 982
 983    def drop_sql(self, expression: exp.Drop) -> str:
 984        this = self.sql(expression, "this")
 985        kind = expression.args["kind"]
 986        exists_sql = " IF EXISTS " if expression.args.get("exists") else " "
 987        temporary = " TEMPORARY" if expression.args.get("temporary") else ""
 988        materialized = " MATERIALIZED" if expression.args.get("materialized") else ""
 989        cascade = " CASCADE" if expression.args.get("cascade") else ""
 990        constraints = " CONSTRAINTS" if expression.args.get("constraints") else ""
 991        purge = " PURGE" if expression.args.get("purge") else ""
 992        return (
 993            f"DROP{temporary}{materialized} {kind}{exists_sql}{this}{cascade}{constraints}{purge}"
 994        )
 995
 996    def except_sql(self, expression: exp.Except) -> str:
 997        return self.prepend_ctes(
 998            expression,
 999            self.set_operation(expression, self.except_op(expression)),
1000        )
1001
1002    def except_op(self, expression: exp.Except) -> str:
1003        return f"EXCEPT{'' if expression.args.get('distinct') else ' ALL'}"
1004
1005    def fetch_sql(self, expression: exp.Fetch) -> str:
1006        direction = expression.args.get("direction")
1007        direction = f" {direction.upper()}" if direction else ""
1008        count = expression.args.get("count")
1009        count = f" {count}" if count else ""
1010        if expression.args.get("percent"):
1011            count = f"{count} PERCENT"
1012        with_ties_or_only = "WITH TIES" if expression.args.get("with_ties") else "ONLY"
1013        return f"{self.seg('FETCH')}{direction}{count} ROWS {with_ties_or_only}"
1014
1015    def filter_sql(self, expression: exp.Filter) -> str:
1016        if self.AGGREGATE_FILTER_SUPPORTED:
1017            this = self.sql(expression, "this")
1018            where = self.sql(expression, "expression").strip()
1019            return f"{this} FILTER({where})"
1020
1021        agg = expression.this.copy()
1022        agg_arg = agg.this
1023        cond = expression.expression.this
1024        agg_arg.replace(exp.If(this=cond.copy(), true=agg_arg.copy()))
1025        return self.sql(agg)
1026
1027    def hint_sql(self, expression: exp.Hint) -> str:
1028        if not self.QUERY_HINTS:
1029            self.unsupported("Hints are not supported")
1030            return ""
1031
1032        return f" /*+ {self.expressions(expression, sep=self.QUERY_HINT_SEP).strip()} */"
1033
1034    def index_sql(self, expression: exp.Index) -> str:
1035        unique = "UNIQUE " if expression.args.get("unique") else ""
1036        primary = "PRIMARY " if expression.args.get("primary") else ""
1037        amp = "AMP " if expression.args.get("amp") else ""
1038        name = self.sql(expression, "this")
1039        name = f"{name} " if name else ""
1040        table = self.sql(expression, "table")
1041        table = f"{self.INDEX_ON} {table}" if table else ""
1042        using = self.sql(expression, "using")
1043        using = f" USING {using}" if using else ""
1044        index = "INDEX " if not table else ""
1045        columns = self.expressions(expression, key="columns", flat=True)
1046        columns = f"({columns})" if columns else ""
1047        partition_by = self.expressions(expression, key="partition_by", flat=True)
1048        partition_by = f" PARTITION BY {partition_by}" if partition_by else ""
1049        where = self.sql(expression, "where")
1050        return f"{unique}{primary}{amp}{index}{name}{table}{using}{columns}{partition_by}{where}"
1051
1052    def identifier_sql(self, expression: exp.Identifier) -> str:
1053        text = expression.name
1054        lower = text.lower()
1055        text = lower if self.normalize and not expression.quoted else text
1056        text = text.replace(self.IDENTIFIER_END, self._escaped_identifier_end)
1057        if (
1058            expression.quoted
1059            or self.can_identify(text, self.identify)
1060            or lower in self.RESERVED_KEYWORDS
1061            or (not self.IDENTIFIERS_CAN_START_WITH_DIGIT and text[:1].isdigit())
1062        ):
1063            text = f"{self.IDENTIFIER_START}{text}{self.IDENTIFIER_END}"
1064        return text
1065
1066    def inputoutputformat_sql(self, expression: exp.InputOutputFormat) -> str:
1067        input_format = self.sql(expression, "input_format")
1068        input_format = f"INPUTFORMAT {input_format}" if input_format else ""
1069        output_format = self.sql(expression, "output_format")
1070        output_format = f"OUTPUTFORMAT {output_format}" if output_format else ""
1071        return self.sep().join((input_format, output_format))
1072
1073    def national_sql(self, expression: exp.National, prefix: str = "N") -> str:
1074        string = self.sql(exp.Literal.string(expression.name))
1075        return f"{prefix}{string}"
1076
1077    def partition_sql(self, expression: exp.Partition) -> str:
1078        return f"PARTITION({self.expressions(expression, flat=True)})"
1079
1080    def properties_sql(self, expression: exp.Properties) -> str:
1081        root_properties = []
1082        with_properties = []
1083
1084        for p in expression.expressions:
1085            p_loc = self.PROPERTIES_LOCATION[p.__class__]
1086            if p_loc == exp.Properties.Location.POST_WITH:
1087                with_properties.append(p.copy())
1088            elif p_loc == exp.Properties.Location.POST_SCHEMA:
1089                root_properties.append(p.copy())
1090
1091        return self.root_properties(
1092            exp.Properties(expressions=root_properties)
1093        ) + self.with_properties(exp.Properties(expressions=with_properties))
1094
1095    def root_properties(self, properties: exp.Properties) -> str:
1096        if properties.expressions:
1097            return self.sep() + self.expressions(properties, indent=False, sep=" ")
1098        return ""
1099
1100    def properties(
1101        self,
1102        properties: exp.Properties,
1103        prefix: str = "",
1104        sep: str = ", ",
1105        suffix: str = "",
1106        wrapped: bool = True,
1107    ) -> str:
1108        if properties.expressions:
1109            expressions = self.expressions(properties, sep=sep, indent=False)
1110            if expressions:
1111                expressions = self.wrap(expressions) if wrapped else expressions
1112                return f"{prefix}{' ' if prefix and prefix != ' ' else ''}{expressions}{suffix}"
1113        return ""
1114
1115    def with_properties(self, properties: exp.Properties) -> str:
1116        return self.properties(properties, prefix=self.seg("WITH"))
1117
1118    def locate_properties(self, properties: exp.Properties) -> t.DefaultDict:
1119        properties_locs = defaultdict(list)
1120        for p in properties.expressions:
1121            p_loc = self.PROPERTIES_LOCATION[p.__class__]
1122            if p_loc != exp.Properties.Location.UNSUPPORTED:
1123                properties_locs[p_loc].append(p.copy())
1124            else:
1125                self.unsupported(f"Unsupported property {p.key}")
1126
1127        return properties_locs
1128
1129    def property_name(self, expression: exp.Property, string_key: bool = False) -> str:
1130        if isinstance(expression.this, exp.Dot):
1131            return self.sql(expression, "this")
1132        return f"'{expression.name}'" if string_key else expression.name
1133
1134    def property_sql(self, expression: exp.Property) -> str:
1135        property_cls = expression.__class__
1136        if property_cls == exp.Property:
1137            return f"{self.property_name(expression)}={self.sql(expression, 'value')}"
1138
1139        property_name = exp.Properties.PROPERTY_TO_NAME.get(property_cls)
1140        if not property_name:
1141            self.unsupported(f"Unsupported property {expression.key}")
1142
1143        return f"{property_name}={self.sql(expression, 'this')}"
1144
1145    def likeproperty_sql(self, expression: exp.LikeProperty) -> str:
1146        options = " ".join(f"{e.name} {self.sql(e, 'value')}" for e in expression.expressions)
1147        options = f" {options}" if options else ""
1148        return f"LIKE {self.sql(expression, 'this')}{options}"
1149
1150    def fallbackproperty_sql(self, expression: exp.FallbackProperty) -> str:
1151        no = "NO " if expression.args.get("no") else ""
1152        protection = " PROTECTION" if expression.args.get("protection") else ""
1153        return f"{no}FALLBACK{protection}"
1154
1155    def journalproperty_sql(self, expression: exp.JournalProperty) -> str:
1156        no = "NO " if expression.args.get("no") else ""
1157        local = expression.args.get("local")
1158        local = f"{local} " if local else ""
1159        dual = "DUAL " if expression.args.get("dual") else ""
1160        before = "BEFORE " if expression.args.get("before") else ""
1161        after = "AFTER " if expression.args.get("after") else ""
1162        return f"{no}{local}{dual}{before}{after}JOURNAL"
1163
1164    def freespaceproperty_sql(self, expression: exp.FreespaceProperty) -> str:
1165        freespace = self.sql(expression, "this")
1166        percent = " PERCENT" if expression.args.get("percent") else ""
1167        return f"FREESPACE={freespace}{percent}"
1168
1169    def checksumproperty_sql(self, expression: exp.ChecksumProperty) -> str:
1170        if expression.args.get("default"):
1171            property = "DEFAULT"
1172        elif expression.args.get("on"):
1173            property = "ON"
1174        else:
1175            property = "OFF"
1176        return f"CHECKSUM={property}"
1177
1178    def mergeblockratioproperty_sql(self, expression: exp.MergeBlockRatioProperty) -> str:
1179        if expression.args.get("no"):
1180            return "NO MERGEBLOCKRATIO"
1181        if expression.args.get("default"):
1182            return "DEFAULT MERGEBLOCKRATIO"
1183
1184        percent = " PERCENT" if expression.args.get("percent") else ""
1185        return f"MERGEBLOCKRATIO={self.sql(expression, 'this')}{percent}"
1186
1187    def datablocksizeproperty_sql(self, expression: exp.DataBlocksizeProperty) -> str:
1188        default = expression.args.get("default")
1189        minimum = expression.args.get("minimum")
1190        maximum = expression.args.get("maximum")
1191        if default or minimum or maximum:
1192            if default:
1193                prop = "DEFAULT"
1194            elif minimum:
1195                prop = "MINIMUM"
1196            else:
1197                prop = "MAXIMUM"
1198            return f"{prop} DATABLOCKSIZE"
1199        units = expression.args.get("units")
1200        units = f" {units}" if units else ""
1201        return f"DATABLOCKSIZE={self.sql(expression, 'size')}{units}"
1202
1203    def blockcompressionproperty_sql(self, expression: exp.BlockCompressionProperty) -> str:
1204        autotemp = expression.args.get("autotemp")
1205        always = expression.args.get("always")
1206        default = expression.args.get("default")
1207        manual = expression.args.get("manual")
1208        never = expression.args.get("never")
1209
1210        if autotemp is not None:
1211            prop = f"AUTOTEMP({self.expressions(autotemp)})"
1212        elif always:
1213            prop = "ALWAYS"
1214        elif default:
1215            prop = "DEFAULT"
1216        elif manual:
1217            prop = "MANUAL"
1218        elif never:
1219            prop = "NEVER"
1220        return f"BLOCKCOMPRESSION={prop}"
1221
1222    def isolatedloadingproperty_sql(self, expression: exp.IsolatedLoadingProperty) -> str:
1223        no = expression.args.get("no")
1224        no = " NO" if no else ""
1225        concurrent = expression.args.get("concurrent")
1226        concurrent = " CONCURRENT" if concurrent else ""
1227
1228        for_ = ""
1229        if expression.args.get("for_all"):
1230            for_ = " FOR ALL"
1231        elif expression.args.get("for_insert"):
1232            for_ = " FOR INSERT"
1233        elif expression.args.get("for_none"):
1234            for_ = " FOR NONE"
1235        return f"WITH{no}{concurrent} ISOLATED LOADING{for_}"
1236
1237    def lockingproperty_sql(self, expression: exp.LockingProperty) -> str:
1238        kind = expression.args.get("kind")
1239        this = f" {self.sql(expression, 'this')}" if expression.this else ""
1240        for_or_in = expression.args.get("for_or_in")
1241        for_or_in = f" {for_or_in}" if for_or_in else ""
1242        lock_type = expression.args.get("lock_type")
1243        override = " OVERRIDE" if expression.args.get("override") else ""
1244        return f"LOCKING {kind}{this}{for_or_in} {lock_type}{override}"
1245
1246    def withdataproperty_sql(self, expression: exp.WithDataProperty) -> str:
1247        data_sql = f"WITH {'NO ' if expression.args.get('no') else ''}DATA"
1248        statistics = expression.args.get("statistics")
1249        statistics_sql = ""
1250        if statistics is not None:
1251            statistics_sql = f" AND {'NO ' if not statistics else ''}STATISTICS"
1252        return f"{data_sql}{statistics_sql}"
1253
1254    def insert_sql(self, expression: exp.Insert) -> str:
1255        overwrite = expression.args.get("overwrite")
1256
1257        if isinstance(expression.this, exp.Directory):
1258            this = " OVERWRITE" if overwrite else " INTO"
1259        else:
1260            this = " OVERWRITE TABLE" if overwrite else " INTO"
1261
1262        alternative = expression.args.get("alternative")
1263        alternative = f" OR {alternative}" if alternative else ""
1264        ignore = " IGNORE" if expression.args.get("ignore") else ""
1265
1266        this = f"{this} {self.sql(expression, 'this')}"
1267
1268        exists = " IF EXISTS" if expression.args.get("exists") else ""
1269        partition_sql = (
1270            f" {self.sql(expression, 'partition')}" if expression.args.get("partition") else ""
1271        )
1272        where = self.sql(expression, "where")
1273        where = f"{self.sep()}REPLACE WHERE {where}" if where else ""
1274        expression_sql = f"{self.sep()}{self.sql(expression, 'expression')}"
1275        conflict = self.sql(expression, "conflict")
1276        by_name = " BY NAME" if expression.args.get("by_name") else ""
1277        returning = self.sql(expression, "returning")
1278
1279        if self.RETURNING_END:
1280            expression_sql = f"{expression_sql}{conflict}{returning}"
1281        else:
1282            expression_sql = f"{returning}{expression_sql}{conflict}"
1283
1284        sql = f"INSERT{alternative}{ignore}{this}{by_name}{exists}{partition_sql}{where}{expression_sql}"
1285        return self.prepend_ctes(expression, sql)
1286
1287    def intersect_sql(self, expression: exp.Intersect) -> str:
1288        return self.prepend_ctes(
1289            expression,
1290            self.set_operation(expression, self.intersect_op(expression)),
1291        )
1292
1293    def intersect_op(self, expression: exp.Intersect) -> str:
1294        return f"INTERSECT{'' if expression.args.get('distinct') else ' ALL'}"
1295
1296    def introducer_sql(self, expression: exp.Introducer) -> str:
1297        return f"{self.sql(expression, 'this')} {self.sql(expression, 'expression')}"
1298
1299    def kill_sql(self, expression: exp.Kill) -> str:
1300        kind = self.sql(expression, "kind")
1301        kind = f" {kind}" if kind else ""
1302        this = self.sql(expression, "this")
1303        this = f" {this}" if this else ""
1304        return f"KILL{kind}{this}"
1305
1306    def pseudotype_sql(self, expression: exp.PseudoType) -> str:
1307        return expression.name.upper()
1308
1309    def objectidentifier_sql(self, expression: exp.ObjectIdentifier) -> str:
1310        return expression.name.upper()
1311
1312    def onconflict_sql(self, expression: exp.OnConflict) -> str:
1313        conflict = "ON DUPLICATE KEY" if expression.args.get("duplicate") else "ON CONFLICT"
1314        constraint = self.sql(expression, "constraint")
1315        if constraint:
1316            constraint = f"ON CONSTRAINT {constraint}"
1317        key = self.expressions(expression, key="key", flat=True)
1318        do = "" if expression.args.get("duplicate") else " DO "
1319        nothing = "NOTHING" if expression.args.get("nothing") else ""
1320        expressions = self.expressions(expression, flat=True)
1321        set_keyword = "SET " if self.DUPLICATE_KEY_UPDATE_WITH_SET else ""
1322        if expressions:
1323            expressions = f"UPDATE {set_keyword}{expressions}"
1324        return f"{self.seg(conflict)} {constraint}{key}{do}{nothing}{expressions}"
1325
1326    def returning_sql(self, expression: exp.Returning) -> str:
1327        return f"{self.seg('RETURNING')} {self.expressions(expression, flat=True)}"
1328
1329    def rowformatdelimitedproperty_sql(self, expression: exp.RowFormatDelimitedProperty) -> str:
1330        fields = expression.args.get("fields")
1331        fields = f" FIELDS TERMINATED BY {fields}" if fields else ""
1332        escaped = expression.args.get("escaped")
1333        escaped = f" ESCAPED BY {escaped}" if escaped else ""
1334        items = expression.args.get("collection_items")
1335        items = f" COLLECTION ITEMS TERMINATED BY {items}" if items else ""
1336        keys = expression.args.get("map_keys")
1337        keys = f" MAP KEYS TERMINATED BY {keys}" if keys else ""
1338        lines = expression.args.get("lines")
1339        lines = f" LINES TERMINATED BY {lines}" if lines else ""
1340        null = expression.args.get("null")
1341        null = f" NULL DEFINED AS {null}" if null else ""
1342        return f"ROW FORMAT DELIMITED{fields}{escaped}{items}{keys}{lines}{null}"
1343
1344    def withtablehint_sql(self, expression: exp.WithTableHint) -> str:
1345        return f"WITH ({self.expressions(expression, flat=True)})"
1346
1347    def indextablehint_sql(self, expression: exp.IndexTableHint) -> str:
1348        this = f"{self.sql(expression, 'this')} INDEX"
1349        target = self.sql(expression, "target")
1350        target = f" FOR {target}" if target else ""
1351        return f"{this}{target} ({self.expressions(expression, flat=True)})"
1352
1353    def table_sql(self, expression: exp.Table, sep: str = " AS ") -> str:
1354        table = ".".join(
1355            part
1356            for part in [
1357                self.sql(expression, "catalog"),
1358                self.sql(expression, "db"),
1359                self.sql(expression, "this"),
1360            ]
1361            if part
1362        )
1363
1364        version = self.sql(expression, "version")
1365        version = f" {version}" if version else ""
1366        alias = self.sql(expression, "alias")
1367        alias = f"{sep}{alias}" if alias else ""
1368        hints = self.expressions(expression, key="hints", sep=" ")
1369        hints = f" {hints}" if hints and self.TABLE_HINTS else ""
1370        pivots = self.expressions(expression, key="pivots", sep=" ", flat=True)
1371        pivots = f" {pivots}" if pivots else ""
1372        joins = self.expressions(expression, key="joins", sep="", skip_first=True)
1373        laterals = self.expressions(expression, key="laterals", sep="")
1374
1375        file_format = self.sql(expression, "format")
1376        if file_format:
1377            pattern = self.sql(expression, "pattern")
1378            pattern = f", PATTERN => {pattern}" if pattern else ""
1379            file_format = f" (FILE_FORMAT => {file_format}{pattern})"
1380
1381        index = self.sql(expression, "index")
1382        index = f" AT {index}" if index else ""
1383
1384        return f"{table}{version}{file_format}{alias}{index}{hints}{pivots}{joins}{laterals}"
1385
1386    def tablesample_sql(
1387        self, expression: exp.TableSample, seed_prefix: str = "SEED", sep=" AS "
1388    ) -> str:
1389        if self.ALIAS_POST_TABLESAMPLE and expression.this.alias:
1390            table = expression.this.copy()
1391            table.set("alias", None)
1392            this = self.sql(table)
1393            alias = f"{sep}{self.sql(expression.this, 'alias')}"
1394        else:
1395            this = self.sql(expression, "this")
1396            alias = ""
1397
1398        method = self.sql(expression, "method")
1399        method = f"{method.upper()} " if method and self.TABLESAMPLE_WITH_METHOD else ""
1400        numerator = self.sql(expression, "bucket_numerator")
1401        denominator = self.sql(expression, "bucket_denominator")
1402        field = self.sql(expression, "bucket_field")
1403        field = f" ON {field}" if field else ""
1404        bucket = f"BUCKET {numerator} OUT OF {denominator}{field}" if numerator else ""
1405        percent = self.sql(expression, "percent")
1406        percent = f"{percent} PERCENT" if percent else ""
1407        rows = self.sql(expression, "rows")
1408        rows = f"{rows} ROWS" if rows else ""
1409
1410        size = self.sql(expression, "size")
1411        if size and self.TABLESAMPLE_SIZE_IS_PERCENT:
1412            size = f"{size} PERCENT"
1413
1414        seed = self.sql(expression, "seed")
1415        seed = f" {seed_prefix} ({seed})" if seed else ""
1416        kind = expression.args.get("kind", "TABLESAMPLE")
1417
1418        expr = f"{bucket}{percent}{rows}{size}"
1419        if self.TABLESAMPLE_REQUIRES_PARENS:
1420            expr = f"({expr})"
1421
1422        return f"{this} {kind} {method}{expr}{seed}{alias}"
1423
1424    def pivot_sql(self, expression: exp.Pivot) -> str:
1425        expressions = self.expressions(expression, flat=True)
1426
1427        if expression.this:
1428            this = self.sql(expression, "this")
1429            if not expressions:
1430                return f"UNPIVOT {this}"
1431
1432            on = f"{self.seg('ON')} {expressions}"
1433            using = self.expressions(expression, key="using", flat=True)
1434            using = f"{self.seg('USING')} {using}" if using else ""
1435            group = self.sql(expression, "group")
1436            return f"PIVOT {this}{on}{using}{group}"
1437
1438        alias = self.sql(expression, "alias")
1439        alias = f" AS {alias}" if alias else ""
1440        unpivot = expression.args.get("unpivot")
1441        direction = "UNPIVOT" if unpivot else "PIVOT"
1442        field = self.sql(expression, "field")
1443        include_nulls = expression.args.get("include_nulls")
1444        if include_nulls is not None:
1445            nulls = " INCLUDE NULLS " if include_nulls else " EXCLUDE NULLS "
1446        else:
1447            nulls = ""
1448        return f"{direction}{nulls}({expressions} FOR {field}){alias}"
1449
1450    def version_sql(self, expression: exp.Version) -> str:
1451        this = f"FOR {expression.name}"
1452        kind = expression.text("kind")
1453        expr = self.sql(expression, "expression")
1454        return f"{this} {kind} {expr}"
1455
1456    def tuple_sql(self, expression: exp.Tuple) -> str:
1457        return f"({self.expressions(expression, flat=True)})"
1458
1459    def update_sql(self, expression: exp.Update) -> str:
1460        this = self.sql(expression, "this")
1461        set_sql = self.expressions(expression, flat=True)
1462        from_sql = self.sql(expression, "from")
1463        where_sql = self.sql(expression, "where")
1464        returning = self.sql(expression, "returning")
1465        order = self.sql(expression, "order")
1466        limit = self.sql(expression, "limit")
1467        if self.RETURNING_END:
1468            expression_sql = f"{from_sql}{where_sql}{returning}"
1469        else:
1470            expression_sql = f"{returning}{from_sql}{where_sql}"
1471        sql = f"UPDATE {this} SET {set_sql}{expression_sql}{order}{limit}"
1472        return self.prepend_ctes(expression, sql)
1473
1474    def values_sql(self, expression: exp.Values) -> str:
1475        # The VALUES clause is still valid in an `INSERT INTO ..` statement, for example
1476        if self.VALUES_AS_TABLE or not expression.find_ancestor(exp.From, exp.Join):
1477            args = self.expressions(expression)
1478            alias = self.sql(expression, "alias")
1479            values = f"VALUES{self.seg('')}{args}"
1480            values = (
1481                f"({values})"
1482                if self.WRAP_DERIVED_VALUES and (alias or isinstance(expression.parent, exp.From))
1483                else values
1484            )
1485            return f"{values} AS {alias}" if alias else values
1486
1487        # Converts `VALUES...` expression into a series of select unions.
1488        expression = expression.copy()
1489        alias_node = expression.args.get("alias")
1490        column_names = alias_node and alias_node.columns
1491
1492        selects: t.List[exp.Subqueryable] = []
1493
1494        for i, tup in enumerate(expression.expressions):
1495            row = tup.expressions
1496
1497            if i == 0 and column_names:
1498                row = [
1499                    exp.alias_(value, column_name) for value, column_name in zip(row, column_names)
1500                ]
1501
1502            selects.append(exp.Select(expressions=row))
1503
1504        if self.pretty:
1505            # This may result in poor performance for large-cardinality `VALUES` tables, due to
1506            # the deep nesting of the resulting exp.Unions. If this is a problem, either increase
1507            # `sys.setrecursionlimit` to avoid RecursionErrors, or don't set `pretty`.
1508            subqueryable = reduce(lambda x, y: exp.union(x, y, distinct=False, copy=False), selects)
1509            return self.subquery_sql(
1510                subqueryable.subquery(alias_node and alias_node.this, copy=False)
1511            )
1512
1513        alias = f" AS {self.sql(alias_node, 'this')}" if alias_node else ""
1514        unions = " UNION ALL ".join(self.sql(select) for select in selects)
1515        return f"({unions}){alias}"
1516
1517    def var_sql(self, expression: exp.Var) -> str:
1518        return self.sql(expression, "this")
1519
1520    def into_sql(self, expression: exp.Into) -> str:
1521        temporary = " TEMPORARY" if expression.args.get("temporary") else ""
1522        unlogged = " UNLOGGED" if expression.args.get("unlogged") else ""
1523        return f"{self.seg('INTO')}{temporary or unlogged} {self.sql(expression, 'this')}"
1524
1525    def from_sql(self, expression: exp.From) -> str:
1526        return f"{self.seg('FROM')} {self.sql(expression, 'this')}"
1527
1528    def group_sql(self, expression: exp.Group) -> str:
1529        group_by = self.op_expressions("GROUP BY", expression)
1530
1531        if expression.args.get("all"):
1532            return f"{group_by} ALL"
1533
1534        grouping_sets = self.expressions(expression, key="grouping_sets", indent=False)
1535        grouping_sets = (
1536            f"{self.seg('GROUPING SETS')} {self.wrap(grouping_sets)}" if grouping_sets else ""
1537        )
1538
1539        cube = expression.args.get("cube", [])
1540        if seq_get(cube, 0) is True:
1541            return f"{group_by}{self.seg('WITH CUBE')}"
1542        else:
1543            cube_sql = self.expressions(expression, key="cube", indent=False)
1544            cube_sql = f"{self.seg('CUBE')} {self.wrap(cube_sql)}" if cube_sql else ""
1545
1546        rollup = expression.args.get("rollup", [])
1547        if seq_get(rollup, 0) is True:
1548            return f"{group_by}{self.seg('WITH ROLLUP')}"
1549        else:
1550            rollup_sql = self.expressions(expression, key="rollup", indent=False)
1551            rollup_sql = f"{self.seg('ROLLUP')} {self.wrap(rollup_sql)}" if rollup_sql else ""
1552
1553        groupings = csv(
1554            grouping_sets,
1555            cube_sql,
1556            rollup_sql,
1557            self.seg("WITH TOTALS") if expression.args.get("totals") else "",
1558            sep=self.GROUPINGS_SEP,
1559        )
1560
1561        if expression.args.get("expressions") and groupings:
1562            group_by = f"{group_by}{self.GROUPINGS_SEP}"
1563
1564        return f"{group_by}{groupings}"
1565
1566    def having_sql(self, expression: exp.Having) -> str:
1567        this = self.indent(self.sql(expression, "this"))
1568        return f"{self.seg('HAVING')}{self.sep()}{this}"
1569
1570    def connect_sql(self, expression: exp.Connect) -> str:
1571        start = self.sql(expression, "start")
1572        start = self.seg(f"START WITH {start}") if start else ""
1573        connect = self.sql(expression, "connect")
1574        connect = self.seg(f"CONNECT BY {connect}")
1575        return start + connect
1576
1577    def prior_sql(self, expression: exp.Prior) -> str:
1578        return f"PRIOR {self.sql(expression, 'this')}"
1579
1580    def join_sql(self, expression: exp.Join) -> str:
1581        if not self.SEMI_ANTI_JOIN_WITH_SIDE and expression.kind in ("SEMI", "ANTI"):
1582            side = None
1583        else:
1584            side = expression.side
1585
1586        op_sql = " ".join(
1587            op
1588            for op in (
1589                expression.method,
1590                "GLOBAL" if expression.args.get("global") else None,
1591                side,
1592                expression.kind,
1593                expression.hint if self.JOIN_HINTS else None,
1594            )
1595            if op
1596        )
1597        on_sql = self.sql(expression, "on")
1598        using = expression.args.get("using")
1599
1600        if not on_sql and using:
1601            on_sql = csv(*(self.sql(column) for column in using))
1602
1603        this_sql = self.sql(expression, "this")
1604
1605        if on_sql:
1606            on_sql = self.indent(on_sql, skip_first=True)
1607            space = self.seg(" " * self.pad) if self.pretty else " "
1608            if using:
1609                on_sql = f"{space}USING ({on_sql})"
1610            else:
1611                on_sql = f"{space}ON {on_sql}"
1612        elif not op_sql:
1613            return f", {this_sql}"
1614
1615        op_sql = f"{op_sql} JOIN" if op_sql else "JOIN"
1616        return f"{self.seg(op_sql)} {this_sql}{on_sql}"
1617
1618    def lambda_sql(self, expression: exp.Lambda, arrow_sep: str = "->") -> str:
1619        args = self.expressions(expression, flat=True)
1620        args = f"({args})" if len(args.split(",")) > 1 else args
1621        return f"{args} {arrow_sep} {self.sql(expression, 'this')}"
1622
1623    def lateral_sql(self, expression: exp.Lateral) -> str:
1624        this = self.sql(expression, "this")
1625
1626        if expression.args.get("view"):
1627            alias = expression.args["alias"]
1628            columns = self.expressions(alias, key="columns", flat=True)
1629            table = f" {alias.name}" if alias.name else ""
1630            columns = f" AS {columns}" if columns else ""
1631            op_sql = self.seg(f"LATERAL VIEW{' OUTER' if expression.args.get('outer') else ''}")
1632            return f"{op_sql}{self.sep()}{this}{table}{columns}"
1633
1634        alias = self.sql(expression, "alias")
1635        alias = f" AS {alias}" if alias else ""
1636        return f"LATERAL {this}{alias}"
1637
1638    def limit_sql(self, expression: exp.Limit, top: bool = False) -> str:
1639        this = self.sql(expression, "this")
1640        args = ", ".join(
1641            self.sql(self._simplify_unless_literal(e) if self.LIMIT_ONLY_LITERALS else e)
1642            for e in (expression.args.get(k) for k in ("offset", "expression"))
1643            if e
1644        )
1645        return f"{this}{self.seg('TOP' if top else 'LIMIT')} {args}"
1646
1647    def offset_sql(self, expression: exp.Offset) -> str:
1648        this = self.sql(expression, "this")
1649        expression = expression.expression
1650        expression = (
1651            self._simplify_unless_literal(expression) if self.LIMIT_ONLY_LITERALS else expression
1652        )
1653        return f"{this}{self.seg('OFFSET')} {self.sql(expression)}"
1654
1655    def setitem_sql(self, expression: exp.SetItem) -> str:
1656        kind = self.sql(expression, "kind")
1657        kind = f"{kind} " if kind else ""
1658        this = self.sql(expression, "this")
1659        expressions = self.expressions(expression)
1660        collate = self.sql(expression, "collate")
1661        collate = f" COLLATE {collate}" if collate else ""
1662        global_ = "GLOBAL " if expression.args.get("global") else ""
1663        return f"{global_}{kind}{this}{expressions}{collate}"
1664
1665    def set_sql(self, expression: exp.Set) -> str:
1666        expressions = (
1667            f" {self.expressions(expression, flat=True)}" if expression.expressions else ""
1668        )
1669        tag = " TAG" if expression.args.get("tag") else ""
1670        return f"{'UNSET' if expression.args.get('unset') else 'SET'}{tag}{expressions}"
1671
1672    def pragma_sql(self, expression: exp.Pragma) -> str:
1673        return f"PRAGMA {self.sql(expression, 'this')}"
1674
1675    def lock_sql(self, expression: exp.Lock) -> str:
1676        if not self.LOCKING_READS_SUPPORTED:
1677            self.unsupported("Locking reads using 'FOR UPDATE/SHARE' are not supported")
1678            return ""
1679
1680        lock_type = "FOR UPDATE" if expression.args["update"] else "FOR SHARE"
1681        expressions = self.expressions(expression, flat=True)
1682        expressions = f" OF {expressions}" if expressions else ""
1683        wait = expression.args.get("wait")
1684
1685        if wait is not None:
1686            if isinstance(wait, exp.Literal):
1687                wait = f" WAIT {self.sql(wait)}"
1688            else:
1689                wait = " NOWAIT" if wait else " SKIP LOCKED"
1690
1691        return f"{lock_type}{expressions}{wait or ''}"
1692
1693    def literal_sql(self, expression: exp.Literal) -> str:
1694        text = expression.this or ""
1695        if expression.is_string:
1696            text = f"{self.QUOTE_START}{self.escape_str(text)}{self.QUOTE_END}"
1697        return text
1698
1699    def escape_str(self, text: str) -> str:
1700        text = text.replace(self.QUOTE_END, self._escaped_quote_end)
1701        if self.INVERSE_ESCAPE_SEQUENCES:
1702            text = "".join(self.INVERSE_ESCAPE_SEQUENCES.get(ch, ch) for ch in text)
1703        elif self.pretty:
1704            text = text.replace("\n", self.SENTINEL_LINE_BREAK)
1705        return text
1706
1707    def loaddata_sql(self, expression: exp.LoadData) -> str:
1708        local = " LOCAL" if expression.args.get("local") else ""
1709        inpath = f" INPATH {self.sql(expression, 'inpath')}"
1710        overwrite = " OVERWRITE" if expression.args.get("overwrite") else ""
1711        this = f" INTO TABLE {self.sql(expression, 'this')}"
1712        partition = self.sql(expression, "partition")
1713        partition = f" {partition}" if partition else ""
1714        input_format = self.sql(expression, "input_format")
1715        input_format = f" INPUTFORMAT {input_format}" if input_format else ""
1716        serde = self.sql(expression, "serde")
1717        serde = f" SERDE {serde}" if serde else ""
1718        return f"LOAD DATA{local}{inpath}{overwrite}{this}{partition}{input_format}{serde}"
1719
1720    def null_sql(self, *_) -> str:
1721        return "NULL"
1722
1723    def boolean_sql(self, expression: exp.Boolean) -> str:
1724        return "TRUE" if expression.this else "FALSE"
1725
1726    def order_sql(self, expression: exp.Order, flat: bool = False) -> str:
1727        this = self.sql(expression, "this")
1728        this = f"{this} " if this else this
1729        return self.op_expressions(f"{this}ORDER BY", expression, flat=this or flat)  # type: ignore
1730
1731    def cluster_sql(self, expression: exp.Cluster) -> str:
1732        return self.op_expressions("CLUSTER BY", expression)
1733
1734    def distribute_sql(self, expression: exp.Distribute) -> str:
1735        return self.op_expressions("DISTRIBUTE BY", expression)
1736
1737    def sort_sql(self, expression: exp.Sort) -> str:
1738        return self.op_expressions("SORT BY", expression)
1739
1740    def ordered_sql(self, expression: exp.Ordered) -> str:
1741        desc = expression.args.get("desc")
1742        asc = not desc
1743
1744        nulls_first = expression.args.get("nulls_first")
1745        nulls_last = not nulls_first
1746        nulls_are_large = self.NULL_ORDERING == "nulls_are_large"
1747        nulls_are_small = self.NULL_ORDERING == "nulls_are_small"
1748        nulls_are_last = self.NULL_ORDERING == "nulls_are_last"
1749
1750        sort_order = " DESC" if desc else (" ASC" if desc is False else "")
1751        nulls_sort_change = ""
1752        if nulls_first and (
1753            (asc and nulls_are_large) or (desc and nulls_are_small) or nulls_are_last
1754        ):
1755            nulls_sort_change = " NULLS FIRST"
1756        elif (
1757            nulls_last
1758            and ((asc and nulls_are_small) or (desc and nulls_are_large))
1759            and not nulls_are_last
1760        ):
1761            nulls_sort_change = " NULLS LAST"
1762
1763        if nulls_sort_change and not self.NULL_ORDERING_SUPPORTED:
1764            self.unsupported(
1765                "Sorting in an ORDER BY on NULLS FIRST/NULLS LAST is not supported by this dialect"
1766            )
1767            nulls_sort_change = ""
1768
1769        return f"{self.sql(expression, 'this')}{sort_order}{nulls_sort_change}"
1770
1771    def matchrecognize_sql(self, expression: exp.MatchRecognize) -> str:
1772        partition = self.partition_by_sql(expression)
1773        order = self.sql(expression, "order")
1774        measures = self.expressions(expression, key="measures")
1775        measures = self.seg(f"MEASURES{self.seg(measures)}") if measures else ""
1776        rows = self.sql(expression, "rows")
1777        rows = self.seg(rows) if rows else ""
1778        after = self.sql(expression, "after")
1779        after = self.seg(after) if after else ""
1780        pattern = self.sql(expression, "pattern")
1781        pattern = self.seg(f"PATTERN ({pattern})") if pattern else ""
1782        definition_sqls = [
1783            f"{self.sql(definition, 'alias')} AS {self.sql(definition, 'this')}"
1784            for definition in expression.args.get("define", [])
1785        ]
1786        definitions = self.expressions(sqls=definition_sqls)
1787        define = self.seg(f"DEFINE{self.seg(definitions)}") if definitions else ""
1788        body = "".join(
1789            (
1790                partition,
1791                order,
1792                measures,
1793                rows,
1794                after,
1795                pattern,
1796                define,
1797            )
1798        )
1799        alias = self.sql(expression, "alias")
1800        alias = f" {alias}" if alias else ""
1801        return f"{self.seg('MATCH_RECOGNIZE')} {self.wrap(body)}{alias}"
1802
1803    def query_modifiers(self, expression: exp.Expression, *sqls: str) -> str:
1804        limit: t.Optional[exp.Fetch | exp.Limit] = expression.args.get("limit")
1805
1806        # If the limit is generated as TOP, we need to ensure it's not generated twice
1807        with_offset_limit_modifiers = not isinstance(limit, exp.Limit) or not self.LIMIT_IS_TOP
1808
1809        if self.LIMIT_FETCH == "LIMIT" and isinstance(limit, exp.Fetch):
1810            limit = exp.Limit(expression=exp.maybe_copy(limit.args.get("count")))
1811        elif self.LIMIT_FETCH == "FETCH" and isinstance(limit, exp.Limit):
1812            limit = exp.Fetch(direction="FIRST", count=exp.maybe_copy(limit.expression))
1813
1814        fetch = isinstance(limit, exp.Fetch)
1815
1816        offset_limit_modifiers = (
1817            self.offset_limit_modifiers(expression, fetch, limit)
1818            if with_offset_limit_modifiers
1819            else []
1820        )
1821
1822        return csv(
1823            *sqls,
1824            *[self.sql(join) for join in expression.args.get("joins") or []],
1825            self.sql(expression, "connect"),
1826            self.sql(expression, "match"),
1827            *[self.sql(lateral) for lateral in expression.args.get("laterals") or []],
1828            self.sql(expression, "where"),
1829            self.sql(expression, "group"),
1830            self.sql(expression, "having"),
1831            *self.after_having_modifiers(expression),
1832            self.sql(expression, "order"),
1833            *offset_limit_modifiers,
1834            *self.after_limit_modifiers(expression),
1835            sep="",
1836        )
1837
1838    def offset_limit_modifiers(
1839        self, expression: exp.Expression, fetch: bool, limit: t.Optional[exp.Fetch | exp.Limit]
1840    ) -> t.List[str]:
1841        return [
1842            self.sql(expression, "offset") if fetch else self.sql(limit),
1843            self.sql(limit) if fetch else self.sql(expression, "offset"),
1844        ]
1845
1846    def after_having_modifiers(self, expression: exp.Expression) -> t.List[str]:
1847        return [
1848            self.sql(expression, "qualify"),
1849            self.seg("WINDOW ") + self.expressions(expression, key="windows", flat=True)
1850            if expression.args.get("windows")
1851            else "",
1852            self.sql(expression, "distribute"),
1853            self.sql(expression, "sort"),
1854            self.sql(expression, "cluster"),
1855        ]
1856
1857    def after_limit_modifiers(self, expression: exp.Expression) -> t.List[str]:
1858        locks = self.expressions(expression, key="locks", sep=" ")
1859        locks = f" {locks}" if locks else ""
1860        return [locks, self.sql(expression, "sample")]
1861
1862    def select_sql(self, expression: exp.Select) -> str:
1863        hint = self.sql(expression, "hint")
1864        distinct = self.sql(expression, "distinct")
1865        distinct = f" {distinct}" if distinct else ""
1866        kind = self.sql(expression, "kind").upper()
1867        limit = expression.args.get("limit")
1868        top = (
1869            self.limit_sql(limit, top=True)
1870            if isinstance(limit, exp.Limit) and self.LIMIT_IS_TOP
1871            else ""
1872        )
1873
1874        expressions = self.expressions(expression)
1875
1876        if kind:
1877            if kind in self.SELECT_KINDS:
1878                kind = f" AS {kind}"
1879            else:
1880                if kind == "STRUCT":
1881                    expressions = self.expressions(
1882                        sqls=[
1883                            self.sql(
1884                                exp.Struct(
1885                                    expressions=[
1886                                        exp.column(e.output_name).eq(
1887                                            e.this if isinstance(e, exp.Alias) else e
1888                                        )
1889                                        for e in expression.expressions
1890                                    ]
1891                                )
1892                            )
1893                        ]
1894                    )
1895                kind = ""
1896
1897        expressions = f"{self.sep()}{expressions}" if expressions else expressions
1898        sql = self.query_modifiers(
1899            expression,
1900            f"SELECT{top}{hint}{distinct}{kind}{expressions}",
1901            self.sql(expression, "into", comment=False),
1902            self.sql(expression, "from", comment=False),
1903        )
1904        return self.prepend_ctes(expression, sql)
1905
1906    def schema_sql(self, expression: exp.Schema) -> str:
1907        this = self.sql(expression, "this")
1908        sql = self.schema_columns_sql(expression)
1909        return f"{this} {sql}" if this and sql else this or sql
1910
1911    def schema_columns_sql(self, expression: exp.Schema) -> str:
1912        if expression.expressions:
1913            return f"({self.sep('')}{self.expressions(expression)}{self.seg(')', sep='')}"
1914        return ""
1915
1916    def star_sql(self, expression: exp.Star) -> str:
1917        except_ = self.expressions(expression, key="except", flat=True)
1918        except_ = f"{self.seg(self.STAR_MAPPING['except'])} ({except_})" if except_ else ""
1919        replace = self.expressions(expression, key="replace", flat=True)
1920        replace = f"{self.seg(self.STAR_MAPPING['replace'])} ({replace})" if replace else ""
1921        return f"*{except_}{replace}"
1922
1923    def parameter_sql(self, expression: exp.Parameter) -> str:
1924        this = self.sql(expression, "this")
1925        return f"{self.PARAMETER_TOKEN}{this}" if self.SUPPORTS_PARAMETERS else this
1926
1927    def sessionparameter_sql(self, expression: exp.SessionParameter) -> str:
1928        this = self.sql(expression, "this")
1929        kind = expression.text("kind")
1930        if kind:
1931            kind = f"{kind}."
1932        return f"@@{kind}{this}"
1933
1934    def placeholder_sql(self, expression: exp.Placeholder) -> str:
1935        return f":{expression.name}" if expression.name else "?"
1936
1937    def subquery_sql(self, expression: exp.Subquery, sep: str = " AS ") -> str:
1938        alias = self.sql(expression, "alias")
1939        alias = f"{sep}{alias}" if alias else ""
1940
1941        pivots = self.expressions(expression, key="pivots", sep=" ", flat=True)
1942        pivots = f" {pivots}" if pivots else ""
1943
1944        sql = self.query_modifiers(expression, self.wrap(expression), alias, pivots)
1945        return self.prepend_ctes(expression, sql)
1946
1947    def qualify_sql(self, expression: exp.Qualify) -> str:
1948        this = self.indent(self.sql(expression, "this"))
1949        return f"{self.seg('QUALIFY')}{self.sep()}{this}"
1950
1951    def union_sql(self, expression: exp.Union) -> str:
1952        return self.prepend_ctes(
1953            expression,
1954            self.set_operation(expression, self.union_op(expression)),
1955        )
1956
1957    def union_op(self, expression: exp.Union) -> str:
1958        kind = " DISTINCT" if self.EXPLICIT_UNION else ""
1959        kind = kind if expression.args.get("distinct") else " ALL"
1960        by_name = " BY NAME" if expression.args.get("by_name") else ""
1961        return f"UNION{kind}{by_name}"
1962
1963    def unnest_sql(self, expression: exp.Unnest) -> str:
1964        args = self.expressions(expression, flat=True)
1965
1966        alias = expression.args.get("alias")
1967        offset = expression.args.get("offset")
1968
1969        if self.UNNEST_WITH_ORDINALITY:
1970            if alias and isinstance(offset, exp.Expression):
1971                alias = alias.copy()
1972                alias.append("columns", offset.copy())
1973
1974        if alias and self.UNNEST_COLUMN_ONLY:
1975            columns = alias.columns
1976            alias = self.sql(columns[0]) if columns else ""
1977        else:
1978            alias = self.sql(alias)
1979
1980        alias = f" AS {alias}" if alias else alias
1981        if self.UNNEST_WITH_ORDINALITY:
1982            suffix = f" WITH ORDINALITY{alias}" if offset else alias
1983        else:
1984            if isinstance(offset, exp.Expression):
1985                suffix = f"{alias} WITH OFFSET AS {self.sql(offset)}"
1986            elif offset:
1987                suffix = f"{alias} WITH OFFSET"
1988            else:
1989                suffix = alias
1990
1991        return f"UNNEST({args}){suffix}"
1992
1993    def where_sql(self, expression: exp.Where) -> str:
1994        this = self.indent(self.sql(expression, "this"))
1995        return f"{self.seg('WHERE')}{self.sep()}{this}"
1996
1997    def window_sql(self, expression: exp.Window) -> str:
1998        this = self.sql(expression, "this")
1999        partition = self.partition_by_sql(expression)
2000        order = expression.args.get("order")
2001        order = self.order_sql(order, flat=True) if order else ""
2002        spec = self.sql(expression, "spec")
2003        alias = self.sql(expression, "alias")
2004        over = self.sql(expression, "over") or "OVER"
2005
2006        this = f"{this} {'AS' if expression.arg_key == 'windows' else over}"
2007
2008        first = expression.args.get("first")
2009        if first is None:
2010            first = ""
2011        else:
2012            first = "FIRST" if first else "LAST"
2013
2014        if not partition and not order and not spec and alias:
2015            return f"{this} {alias}"
2016
2017        args = " ".join(arg for arg in (alias, first, partition, order, spec) if arg)
2018        return f"{this} ({args})"
2019
2020    def partition_by_sql(self, expression: exp.Window | exp.MatchRecognize) -> str:
2021        partition = self.expressions(expression, key="partition_by", flat=True)
2022        return f"PARTITION BY {partition}" if partition else ""
2023
2024    def windowspec_sql(self, expression: exp.WindowSpec) -> str:
2025        kind = self.sql(expression, "kind")
2026        start = csv(self.sql(expression, "start"), self.sql(expression, "start_side"), sep=" ")
2027        end = (
2028            csv(self.sql(expression, "end"), self.sql(expression, "end_side"), sep=" ")
2029            or "CURRENT ROW"
2030        )
2031        return f"{kind} BETWEEN {start} AND {end}"
2032
2033    def withingroup_sql(self, expression: exp.WithinGroup) -> str:
2034        this = self.sql(expression, "this")
2035        expression_sql = self.sql(expression, "expression")[1:]  # order has a leading space
2036        return f"{this} WITHIN GROUP ({expression_sql})"
2037
2038    def between_sql(self, expression: exp.Between) -> str:
2039        this = self.sql(expression, "this")
2040        low = self.sql(expression, "low")
2041        high = self.sql(expression, "high")
2042        return f"{this} BETWEEN {low} AND {high}"
2043
2044    def bracket_sql(self, expression: exp.Bracket) -> str:
2045        expressions = apply_index_offset(expression.this, expression.expressions, self.INDEX_OFFSET)
2046        expressions_sql = ", ".join(self.sql(e) for e in expressions)
2047
2048        return f"{self.sql(expression, 'this')}[{expressions_sql}]"
2049
2050    def safebracket_sql(self, expression: exp.SafeBracket) -> str:
2051        return self.bracket_sql(expression)
2052
2053    def all_sql(self, expression: exp.All) -> str:
2054        return f"ALL {self.wrap(expression)}"
2055
2056    def any_sql(self, expression: exp.Any) -> str:
2057        this = self.sql(expression, "this")
2058        if isinstance(expression.this, exp.Subqueryable):
2059            this = self.wrap(this)
2060        return f"ANY {this}"
2061
2062    def exists_sql(self, expression: exp.Exists) -> str:
2063        return f"EXISTS{self.wrap(expression)}"
2064
2065    def case_sql(self, expression: exp.Case) -> str:
2066        this = self.sql(expression, "this")
2067        statements = [f"CASE {this}" if this else "CASE"]
2068
2069        for e in expression.args["ifs"]:
2070            statements.append(f"WHEN {self.sql(e, 'this')}")
2071            statements.append(f"THEN {self.sql(e, 'true')}")
2072
2073        default = self.sql(expression, "default")
2074
2075        if default:
2076            statements.append(f"ELSE {default}")
2077
2078        statements.append("END")
2079
2080        if self.pretty and self.text_width(statements) > self.max_text_width:
2081            return self.indent("\n".join(statements), skip_first=True, skip_last=True)
2082
2083        return " ".join(statements)
2084
2085    def constraint_sql(self, expression: exp.Constraint) -> str:
2086        this = self.sql(expression, "this")
2087        expressions = self.expressions(expression, flat=True)
2088        return f"CONSTRAINT {this} {expressions}"
2089
2090    def nextvaluefor_sql(self, expression: exp.NextValueFor) -> str:
2091        order = expression.args.get("order")
2092        order = f" OVER ({self.order_sql(order, flat=True)})" if order else ""
2093        return f"NEXT VALUE FOR {self.sql(expression, 'this')}{order}"
2094
2095    def extract_sql(self, expression: exp.Extract) -> str:
2096        this = self.sql(expression, "this") if self.EXTRACT_ALLOWS_QUOTES else expression.this.name
2097        expression_sql = self.sql(expression, "expression")
2098        return f"EXTRACT({this} FROM {expression_sql})"
2099
2100    def trim_sql(self, expression: exp.Trim) -> str:
2101        trim_type = self.sql(expression, "position")
2102
2103        if trim_type == "LEADING":
2104            return self.func("LTRIM", expression.this)
2105        elif trim_type == "TRAILING":
2106            return self.func("RTRIM", expression.this)
2107        else:
2108            return self.func("TRIM", expression.this, expression.expression)
2109
2110    def safeconcat_sql(self, expression: exp.SafeConcat) -> str:
2111        expressions = expression.expressions
2112        if self.STRICT_STRING_CONCAT:
2113            expressions = (exp.cast(e, "text") for e in expressions)
2114        return self.func("CONCAT", *expressions)
2115
2116    def check_sql(self, expression: exp.Check) -> str:
2117        this = self.sql(expression, key="this")
2118        return f"CHECK ({this})"
2119
2120    def foreignkey_sql(self, expression: exp.ForeignKey) -> str:
2121        expressions = self.expressions(expression, flat=True)
2122        reference = self.sql(expression, "reference")
2123        reference = f" {reference}" if reference else ""
2124        delete = self.sql(expression, "delete")
2125        delete = f" ON DELETE {delete}" if delete else ""
2126        update = self.sql(expression, "update")
2127        update = f" ON UPDATE {update}" if update else ""
2128        return f"FOREIGN KEY ({expressions}){reference}{delete}{update}"
2129
2130    def primarykey_sql(self, expression: exp.ForeignKey) -> str:
2131        expressions = self.expressions(expression, flat=True)
2132        options = self.expressions(expression, key="options", flat=True, sep=" ")
2133        options = f" {options}" if options else ""
2134        return f"PRIMARY KEY ({expressions}){options}"
2135
2136    def if_sql(self, expression: exp.If) -> str:
2137        expression = expression.copy()
2138        return self.case_sql(exp.Case(ifs=[expression], default=expression.args.get("false")))
2139
2140    def matchagainst_sql(self, expression: exp.MatchAgainst) -> str:
2141        modifier = expression.args.get("modifier")
2142        modifier = f" {modifier}" if modifier else ""
2143        return f"{self.func('MATCH', *expression.expressions)} AGAINST({self.sql(expression, 'this')}{modifier})"
2144
2145    def jsonkeyvalue_sql(self, expression: exp.JSONKeyValue) -> str:
2146        return f"{self.sql(expression, 'this')}: {self.sql(expression, 'expression')}"
2147
2148    def formatjson_sql(self, expression: exp.FormatJson) -> str:
2149        return f"{self.sql(expression, 'this')} FORMAT JSON"
2150
2151    def jsonobject_sql(self, expression: exp.JSONObject) -> str:
2152        null_handling = expression.args.get("null_handling")
2153        null_handling = f" {null_handling}" if null_handling else ""
2154        unique_keys = expression.args.get("unique_keys")
2155        if unique_keys is not None:
2156            unique_keys = f" {'WITH' if unique_keys else 'WITHOUT'} UNIQUE KEYS"
2157        else:
2158            unique_keys = ""
2159        return_type = self.sql(expression, "return_type")
2160        return_type = f" RETURNING {return_type}" if return_type else ""
2161        encoding = self.sql(expression, "encoding")
2162        encoding = f" ENCODING {encoding}" if encoding else ""
2163        return self.func(
2164            "JSON_OBJECT",
2165            *expression.expressions,
2166            suffix=f"{null_handling}{unique_keys}{return_type}{encoding})",
2167        )
2168
2169    def jsonarray_sql(self, expression: exp.JSONArray) -> str:
2170        null_handling = expression.args.get("null_handling")
2171        null_handling = f" {null_handling}" if null_handling else ""
2172        return_type = self.sql(expression, "return_type")
2173        return_type = f" RETURNING {return_type}" if return_type else ""
2174        strict = " STRICT" if expression.args.get("strict") else ""
2175        return self.func(
2176            "JSON_ARRAY", *expression.expressions, suffix=f"{null_handling}{return_type}{strict})"
2177        )
2178
2179    def jsonarrayagg_sql(self, expression: exp.JSONArrayAgg) -> str:
2180        this = self.sql(expression, "this")
2181        order = self.sql(expression, "order")
2182        null_handling = expression.args.get("null_handling")
2183        null_handling = f" {null_handling}" if null_handling else ""
2184        return_type = self.sql(expression, "return_type")
2185        return_type = f" RETURNING {return_type}" if return_type else ""
2186        strict = " STRICT" if expression.args.get("strict") else ""
2187        return self.func(
2188            "JSON_ARRAYAGG",
2189            this,
2190            suffix=f"{order}{null_handling}{return_type}{strict})",
2191        )
2192
2193    def jsoncolumndef_sql(self, expression: exp.JSONColumnDef) -> str:
2194        path = self.sql(expression, "path")
2195        path = f" PATH {path}" if path else ""
2196        nested_schema = self.sql(expression, "nested_schema")
2197
2198        if nested_schema:
2199            return f"NESTED{path} {nested_schema}"
2200
2201        this = self.sql(expression, "this")
2202        kind = self.sql(expression, "kind")
2203        kind = f" {kind}" if kind else ""
2204        return f"{this}{kind}{path}"
2205
2206    def jsonschema_sql(self, expression: exp.JSONSchema) -> str:
2207        return self.func("COLUMNS", *expression.expressions)
2208
2209    def jsontable_sql(self, expression: exp.JSONTable) -> str:
2210        this = self.sql(expression, "this")
2211        path = self.sql(expression, "path")
2212        path = f", {path}" if path else ""
2213        error_handling = expression.args.get("error_handling")
2214        error_handling = f" {error_handling}" if error_handling else ""
2215        empty_handling = expression.args.get("empty_handling")
2216        empty_handling = f" {empty_handling}" if empty_handling else ""
2217        schema = self.sql(expression, "schema")
2218        return self.func(
2219            "JSON_TABLE", this, suffix=f"{path}{error_handling}{empty_handling} {schema})"
2220        )
2221
2222    def openjsoncolumndef_sql(self, expression: exp.OpenJSONColumnDef) -> str:
2223        this = self.sql(expression, "this")
2224        kind = self.sql(expression, "kind")
2225        path = self.sql(expression, "path")
2226        path = f" {path}" if path else ""
2227        as_json = " AS JSON" if expression.args.get("as_json") else ""
2228        return f"{this} {kind}{path}{as_json}"
2229
2230    def openjson_sql(self, expression: exp.OpenJSON) -> str:
2231        this = self.sql(expression, "this")
2232        path = self.sql(expression, "path")
2233        path = f", {path}" if path else ""
2234        expressions = self.expressions(expression)
2235        with_ = (
2236            f" WITH ({self.seg(self.indent(expressions), sep='')}{self.seg(')', sep='')}"
2237            if expressions
2238            else ""
2239        )
2240        return f"OPENJSON({this}{path}){with_}"
2241
2242    def in_sql(self, expression: exp.In) -> str:
2243        query = expression.args.get("query")
2244        unnest = expression.args.get("unnest")
2245        field = expression.args.get("field")
2246        is_global = " GLOBAL" if expression.args.get("is_global") else ""
2247
2248        if query:
2249            in_sql = self.wrap(query)
2250        elif unnest:
2251            in_sql = self.in_unnest_op(unnest)
2252        elif field:
2253            in_sql = self.sql(field)
2254        else:
2255            in_sql = f"({self.expressions(expression, flat=True)})"
2256
2257        return f"{self.sql(expression, 'this')}{is_global} IN {in_sql}"
2258
2259    def in_unnest_op(self, unnest: exp.Unnest) -> str:
2260        return f"(SELECT {self.sql(unnest)})"
2261
2262    def interval_sql(self, expression: exp.Interval) -> str:
2263        unit = self.sql(expression, "unit")
2264        if not self.INTERVAL_ALLOWS_PLURAL_FORM:
2265            unit = self.TIME_PART_SINGULARS.get(unit.lower(), unit)
2266        unit = f" {unit}" if unit else ""
2267
2268        if self.SINGLE_STRING_INTERVAL:
2269            this = expression.this.name if expression.this else ""
2270            return f"INTERVAL '{this}{unit}'" if this else f"INTERVAL{unit}"
2271
2272        this = self.sql(expression, "this")
2273        if this:
2274            unwrapped = isinstance(expression.this, self.UNWRAPPED_INTERVAL_VALUES)
2275            this = f" {this}" if unwrapped else f" ({this})"
2276
2277        return f"INTERVAL{this}{unit}"
2278
2279    def return_sql(self, expression: exp.Return) -> str:
2280        return f"RETURN {self.sql(expression, 'this')}"
2281
2282    def reference_sql(self, expression: exp.Reference) -> str:
2283        this = self.sql(expression, "this")
2284        expressions = self.expressions(expression, flat=True)
2285        expressions = f"({expressions})" if expressions else ""
2286        options = self.expressions(expression, key="options", flat=True, sep=" ")
2287        options = f" {options}" if options else ""
2288        return f"REFERENCES {this}{expressions}{options}"
2289
2290    def anonymous_sql(self, expression: exp.Anonymous) -> str:
2291        return self.func(expression.name, *expression.expressions)
2292
2293    def paren_sql(self, expression: exp.Paren) -> str:
2294        if isinstance(expression.unnest(), exp.Select):
2295            sql = self.wrap(expression)
2296        else:
2297            sql = self.seg(self.indent(self.sql(expression, "this")), sep="")
2298            sql = f"({sql}{self.seg(')', sep='')}"
2299
2300        return self.prepend_ctes(expression, sql)
2301
2302    def neg_sql(self, expression: exp.Neg) -> str:
2303        # This makes sure we don't convert "- - 5" to "--5", which is a comment
2304        this_sql = self.sql(expression, "this")
2305        sep = " " if this_sql[0] == "-" else ""
2306        return f"-{sep}{this_sql}"
2307
2308    def not_sql(self, expression: exp.Not) -> str:
2309        return f"NOT {self.sql(expression, 'this')}"
2310
2311    def alias_sql(self, expression: exp.Alias) -> str:
2312        alias = self.sql(expression, "alias")
2313        alias = f" AS {alias}" if alias else ""
2314        return f"{self.sql(expression, 'this')}{alias}"
2315
2316    def aliases_sql(self, expression: exp.Aliases) -> str:
2317        return f"{self.sql(expression, 'this')} AS ({self.expressions(expression, flat=True)})"
2318
2319    def attimezone_sql(self, expression: exp.AtTimeZone) -> str:
2320        this = self.sql(expression, "this")
2321        zone = self.sql(expression, "zone")
2322        return f"{this} AT TIME ZONE {zone}"
2323
2324    def add_sql(self, expression: exp.Add) -> str:
2325        return self.binary(expression, "+")
2326
2327    def and_sql(self, expression: exp.And) -> str:
2328        return self.connector_sql(expression, "AND")
2329
2330    def xor_sql(self, expression: exp.Xor) -> str:
2331        return self.connector_sql(expression, "XOR")
2332
2333    def connector_sql(self, expression: exp.Connector, op: str) -> str:
2334        if not self.pretty:
2335            return self.binary(expression, op)
2336
2337        sqls = tuple(
2338            self.maybe_comment(self.sql(e), e, e.parent.comments or []) if i != 1 else self.sql(e)
2339            for i, e in enumerate(expression.flatten(unnest=False))
2340        )
2341
2342        sep = "\n" if self.text_width(sqls) > self.max_text_width else " "
2343        return f"{sep}{op} ".join(sqls)
2344
2345    def bitwiseand_sql(self, expression: exp.BitwiseAnd) -> str:
2346        return self.binary(expression, "&")
2347
2348    def bitwiseleftshift_sql(self, expression: exp.BitwiseLeftShift) -> str:
2349        return self.binary(expression, "<<")
2350
2351    def bitwisenot_sql(self, expression: exp.BitwiseNot) -> str:
2352        return f"~{self.sql(expression, 'this')}"
2353
2354    def bitwiseor_sql(self, expression: exp.BitwiseOr) -> str:
2355        return self.binary(expression, "|")
2356
2357    def bitwiserightshift_sql(self, expression: exp.BitwiseRightShift) -> str:
2358        return self.binary(expression, ">>")
2359
2360    def bitwisexor_sql(self, expression: exp.BitwiseXor) -> str:
2361        return self.binary(expression, "^")
2362
2363    def cast_sql(self, expression: exp.Cast, safe_prefix: t.Optional[str] = None) -> str:
2364        format_sql = self.sql(expression, "format")
2365        format_sql = f" FORMAT {format_sql}" if format_sql else ""
2366        return f"{safe_prefix or ''}CAST({self.sql(expression, 'this')} AS {self.sql(expression, 'to')}{format_sql})"
2367
2368    def currentdate_sql(self, expression: exp.CurrentDate) -> str:
2369        zone = self.sql(expression, "this")
2370        return f"CURRENT_DATE({zone})" if zone else "CURRENT_DATE"
2371
2372    def collate_sql(self, expression: exp.Collate) -> str:
2373        if self.COLLATE_IS_FUNC:
2374            return self.function_fallback_sql(expression)
2375        return self.binary(expression, "COLLATE")
2376
2377    def command_sql(self, expression: exp.Command) -> str:
2378        return f"{self.sql(expression, 'this').upper()} {expression.text('expression').strip()}"
2379
2380    def comment_sql(self, expression: exp.Comment) -> str:
2381        this = self.sql(expression, "this")
2382        kind = expression.args["kind"]
2383        exists_sql = " IF EXISTS " if expression.args.get("exists") else " "
2384        expression_sql = self.sql(expression, "expression")
2385        return f"COMMENT{exists_sql}ON {kind} {this} IS {expression_sql}"
2386
2387    def mergetreettlaction_sql(self, expression: exp.MergeTreeTTLAction) -> str:
2388        this = self.sql(expression, "this")
2389        delete = " DELETE" if expression.args.get("delete") else ""
2390        recompress = self.sql(expression, "recompress")
2391        recompress = f" RECOMPRESS {recompress}" if recompress else ""
2392        to_disk = self.sql(expression, "to_disk")
2393        to_disk = f" TO DISK {to_disk}" if to_disk else ""
2394        to_volume = self.sql(expression, "to_volume")
2395        to_volume = f" TO VOLUME {to_volume}" if to_volume else ""
2396        return f"{this}{delete}{recompress}{to_disk}{to_volume}"
2397
2398    def mergetreettl_sql(self, expression: exp.MergeTreeTTL) -> str:
2399        where = self.sql(expression, "where")
2400        group = self.sql(expression, "group")
2401        aggregates = self.expressions(expression, key="aggregates")
2402        aggregates = self.seg("SET") + self.seg(aggregates) if aggregates else ""
2403
2404        if not (where or group or aggregates) and len(expression.expressions) == 1:
2405            return f"TTL {self.expressions(expression, flat=True)}"
2406
2407        return f"TTL{self.seg(self.expressions(expression))}{where}{group}{aggregates}"
2408
2409    def transaction_sql(self, expression: exp.Transaction) -> str:
2410        return "BEGIN"
2411
2412    def commit_sql(self, expression: exp.Commit) -> str:
2413        chain = expression.args.get("chain")
2414        if chain is not None:
2415            chain = " AND CHAIN" if chain else " AND NO CHAIN"
2416
2417        return f"COMMIT{chain or ''}"
2418
2419    def rollback_sql(self, expression: exp.Rollback) -> str:
2420        savepoint = expression.args.get("savepoint")
2421        savepoint = f" TO {savepoint}" if savepoint else ""
2422        return f"ROLLBACK{savepoint}"
2423
2424    def altercolumn_sql(self, expression: exp.AlterColumn) -> str:
2425        this = self.sql(expression, "this")
2426
2427        dtype = self.sql(expression, "dtype")
2428        if dtype:
2429            collate = self.sql(expression, "collate")
2430            collate = f" COLLATE {collate}" if collate else ""
2431            using = self.sql(expression, "using")
2432            using = f" USING {using}" if using else ""
2433            return f"ALTER COLUMN {this} SET DATA TYPE {dtype}{collate}{using}"
2434
2435        default = self.sql(expression, "default")
2436        if default:
2437            return f"ALTER COLUMN {this} SET DEFAULT {default}"
2438
2439        if not expression.args.get("drop"):
2440            self.unsupported("Unsupported ALTER COLUMN syntax")
2441
2442        return f"ALTER COLUMN {this} DROP DEFAULT"
2443
2444    def renametable_sql(self, expression: exp.RenameTable) -> str:
2445        if not self.RENAME_TABLE_WITH_DB:
2446            # Remove db from tables
2447            expression = expression.transform(
2448                lambda n: exp.table_(n.this) if isinstance(n, exp.Table) else n
2449            )
2450        this = self.sql(expression, "this")
2451        return f"RENAME TO {this}"
2452
2453    def altertable_sql(self, expression: exp.AlterTable) -> str:
2454        actions = expression.args["actions"]
2455
2456        if isinstance(actions[0], exp.ColumnDef):
2457            if self.ALTER_TABLE_ADD_COLUMN_KEYWORD:
2458                actions = self.expressions(
2459                    expression,
2460                    key="actions",
2461                    prefix="ADD COLUMN ",
2462                )
2463            else:
2464                actions = f"ADD {self.expressions(expression, key='actions')}"
2465        elif isinstance(actions[0], exp.Schema):
2466            actions = self.expressions(expression, key="actions", prefix="ADD COLUMNS ")
2467        elif isinstance(actions[0], exp.Delete):
2468            actions = self.expressions(expression, key="actions", flat=True)
2469        else:
2470            actions = self.expressions(expression, key="actions", flat=True)
2471
2472        exists = " IF EXISTS" if expression.args.get("exists") else ""
2473        only = " ONLY" if expression.args.get("only") else ""
2474        return f"ALTER TABLE{exists}{only} {self.sql(expression, 'this')} {actions}"
2475
2476    def droppartition_sql(self, expression: exp.DropPartition) -> str:
2477        expressions = self.expressions(expression)
2478        exists = " IF EXISTS " if expression.args.get("exists") else " "
2479        return f"DROP{exists}{expressions}"
2480
2481    def addconstraint_sql(self, expression: exp.AddConstraint) -> str:
2482        this = self.sql(expression, "this")
2483        expression_ = self.sql(expression, "expression")
2484        add_constraint = f"ADD CONSTRAINT {this}" if this else "ADD"
2485
2486        enforced = expression.args.get("enforced")
2487        if enforced is not None:
2488            return f"{add_constraint} CHECK ({expression_}){' ENFORCED' if enforced else ''}"
2489
2490        return f"{add_constraint} {expression_}"
2491
2492    def distinct_sql(self, expression: exp.Distinct) -> str:
2493        this = self.expressions(expression, flat=True)
2494        this = f" {this}" if this else ""
2495
2496        on = self.sql(expression, "on")
2497        on = f" ON {on}" if on else ""
2498        return f"DISTINCT{this}{on}"
2499
2500    def ignorenulls_sql(self, expression: exp.IgnoreNulls) -> str:
2501        return f"{self.sql(expression, 'this')} IGNORE NULLS"
2502
2503    def respectnulls_sql(self, expression: exp.RespectNulls) -> str:
2504        return f"{self.sql(expression, 'this')} RESPECT NULLS"
2505
2506    def intdiv_sql(self, expression: exp.IntDiv) -> str:
2507        return self.sql(
2508            exp.Cast(
2509                this=exp.Div(this=expression.this.copy(), expression=expression.expression.copy()),
2510                to=exp.DataType(this=exp.DataType.Type.INT),
2511            )
2512        )
2513
2514    def dpipe_sql(self, expression: exp.DPipe) -> str:
2515        return self.binary(expression, "||")
2516
2517    def safedpipe_sql(self, expression: exp.SafeDPipe) -> str:
2518        if self.STRICT_STRING_CONCAT:
2519            return self.func("CONCAT", *(exp.cast(e, "text") for e in expression.flatten()))
2520        return self.dpipe_sql(expression)
2521
2522    def div_sql(self, expression: exp.Div) -> str:
2523        return self.binary(expression, "/")
2524
2525    def overlaps_sql(self, expression: exp.Overlaps) -> str:
2526        return self.binary(expression, "OVERLAPS")
2527
2528    def distance_sql(self, expression: exp.Distance) -> str:
2529        return self.binary(expression, "<->")
2530
2531    def dot_sql(self, expression: exp.Dot) -> str:
2532        return f"{self.sql(expression, 'this')}.{self.sql(expression, 'expression')}"
2533
2534    def eq_sql(self, expression: exp.EQ) -> str:
2535        return self.binary(expression, "=")
2536
2537    def escape_sql(self, expression: exp.Escape) -> str:
2538        return self.binary(expression, "ESCAPE")
2539
2540    def glob_sql(self, expression: exp.Glob) -> str:
2541        return self.binary(expression, "GLOB")
2542
2543    def gt_sql(self, expression: exp.GT) -> str:
2544        return self.binary(expression, ">")
2545
2546    def gte_sql(self, expression: exp.GTE) -> str:
2547        return self.binary(expression, ">=")
2548
2549    def ilike_sql(self, expression: exp.ILike) -> str:
2550        return self.binary(expression, "ILIKE")
2551
2552    def ilikeany_sql(self, expression: exp.ILikeAny) -> str:
2553        return self.binary(expression, "ILIKE ANY")
2554
2555    def is_sql(self, expression: exp.Is) -> str:
2556        if not self.IS_BOOL_ALLOWED and isinstance(expression.expression, exp.Boolean):
2557            return self.sql(
2558                expression.this if expression.expression.this else exp.not_(expression.this)
2559            )
2560        return self.binary(expression, "IS")
2561
2562    def like_sql(self, expression: exp.Like) -> str:
2563        return self.binary(expression, "LIKE")
2564
2565    def likeany_sql(self, expression: exp.LikeAny) -> str:
2566        return self.binary(expression, "LIKE ANY")
2567
2568    def similarto_sql(self, expression: exp.SimilarTo) -> str:
2569        return self.binary(expression, "SIMILAR TO")
2570
2571    def lt_sql(self, expression: exp.LT) -> str:
2572        return self.binary(expression, "<")
2573
2574    def lte_sql(self, expression: exp.LTE) -> str:
2575        return self.binary(expression, "<=")
2576
2577    def mod_sql(self, expression: exp.Mod) -> str:
2578        return self.binary(expression, "%")
2579
2580    def mul_sql(self, expression: exp.Mul) -> str:
2581        return self.binary(expression, "*")
2582
2583    def neq_sql(self, expression: exp.NEQ) -> str:
2584        return self.binary(expression, "<>")
2585
2586    def nullsafeeq_sql(self, expression: exp.NullSafeEQ) -> str:
2587        return self.binary(expression, "IS NOT DISTINCT FROM")
2588
2589    def nullsafeneq_sql(self, expression: exp.NullSafeNEQ) -> str:
2590        return self.binary(expression, "IS DISTINCT FROM")
2591
2592    def or_sql(self, expression: exp.Or) -> str:
2593        return self.connector_sql(expression, "OR")
2594
2595    def slice_sql(self, expression: exp.Slice) -> str:
2596        return self.binary(expression, ":")
2597
2598    def sub_sql(self, expression: exp.Sub) -> str:
2599        return self.binary(expression, "-")
2600
2601    def trycast_sql(self, expression: exp.TryCast) -> str:
2602        return self.cast_sql(expression, safe_prefix="TRY_")
2603
2604    def log_sql(self, expression: exp.Log) -> str:
2605        args = list(expression.args.values())
2606        if not self.LOG_BASE_FIRST:
2607            args.reverse()
2608        return self.func("LOG", *args)
2609
2610    def use_sql(self, expression: exp.Use) -> str:
2611        kind = self.sql(expression, "kind")
2612        kind = f" {kind}" if kind else ""
2613        this = self.sql(expression, "this")
2614        this = f" {this}" if this else ""
2615        return f"USE{kind}{this}"
2616
2617    def binary(self, expression: exp.Binary, op: str) -> str:
2618        op = self.maybe_comment(op, comments=expression.comments)
2619        return f"{self.sql(expression, 'this')} {op} {self.sql(expression, 'expression')}"
2620
2621    def function_fallback_sql(self, expression: exp.Func) -> str:
2622        args = []
2623
2624        for key in expression.arg_types:
2625            arg_value = expression.args.get(key)
2626
2627            if isinstance(arg_value, list):
2628                for value in arg_value:
2629                    args.append(value)
2630            elif arg_value is not None:
2631                args.append(arg_value)
2632
2633        if self.normalize_functions:
2634            name = expression.sql_name()
2635        else:
2636            name = (expression._meta and expression.meta.get("name")) or expression.sql_name()
2637
2638        return self.func(name, *args)
2639
2640    def func(
2641        self,
2642        name: str,
2643        *args: t.Optional[exp.Expression | str],
2644        prefix: str = "(",
2645        suffix: str = ")",
2646    ) -> str:
2647        return f"{self.normalize_func(name)}{prefix}{self.format_args(*args)}{suffix}"
2648
2649    def format_args(self, *args: t.Optional[str | exp.Expression]) -> str:
2650        arg_sqls = tuple(self.sql(arg) for arg in args if arg is not None)
2651        if self.pretty and self.text_width(arg_sqls) > self.max_text_width:
2652            return self.indent("\n" + f",\n".join(arg_sqls) + "\n", skip_first=True, skip_last=True)
2653        return ", ".join(arg_sqls)
2654
2655    def text_width(self, args: t.Iterable) -> int:
2656        return sum(len(arg) for arg in args)
2657
2658    def format_time(self, expression: exp.Expression) -> t.Optional[str]:
2659        return format_time(
2660            self.sql(expression, "format"), self.INVERSE_TIME_MAPPING, self.INVERSE_TIME_TRIE
2661        )
2662
2663    def expressions(
2664        self,
2665        expression: t.Optional[exp.Expression] = None,
2666        key: t.Optional[str] = None,
2667        sqls: t.Optional[t.Collection[str | exp.Expression]] = None,
2668        flat: bool = False,
2669        indent: bool = True,
2670        skip_first: bool = False,
2671        sep: str = ", ",
2672        prefix: str = "",
2673    ) -> str:
2674        expressions = expression.args.get(key or "expressions") if expression else sqls
2675
2676        if not expressions:
2677            return ""
2678
2679        if flat:
2680            return sep.join(sql for sql in (self.sql(e) for e in expressions) if sql)
2681
2682        num_sqls = len(expressions)
2683
2684        # These are calculated once in case we have the leading_comma / pretty option set, correspondingly
2685        pad = " " * self.pad
2686        stripped_sep = sep.strip()
2687
2688        result_sqls = []
2689        for i, e in enumerate(expressions):
2690            sql = self.sql(e, comment=False)
2691            if not sql:
2692                continue
2693
2694            comments = self.maybe_comment("", e) if isinstance(e, exp.Expression) else ""
2695
2696            if self.pretty:
2697                if self.leading_comma:
2698                    result_sqls.append(f"{sep if i > 0 else pad}{prefix}{sql}{comments}")
2699                else:
2700                    result_sqls.append(
2701                        f"{prefix}{sql}{stripped_sep if i + 1 < num_sqls else ''}{comments}"
2702                    )
2703            else:
2704                result_sqls.append(f"{prefix}{sql}{comments}{sep if i + 1 < num_sqls else ''}")
2705
2706        result_sql = "\n".join(result_sqls) if self.pretty else "".join(result_sqls)
2707        return self.indent(result_sql, skip_first=skip_first) if indent else result_sql
2708
2709    def op_expressions(self, op: str, expression: exp.Expression, flat: bool = False) -> str:
2710        flat = flat or isinstance(expression.parent, exp.Properties)
2711        expressions_sql = self.expressions(expression, flat=flat)
2712        if flat:
2713            return f"{op} {expressions_sql}"
2714        return f"{self.seg(op)}{self.sep() if expressions_sql else ''}{expressions_sql}"
2715
2716    def naked_property(self, expression: exp.Property) -> str:
2717        property_name = exp.Properties.PROPERTY_TO_NAME.get(expression.__class__)
2718        if not property_name:
2719            self.unsupported(f"Unsupported property {expression.__class__.__name__}")
2720        return f"{property_name} {self.sql(expression, 'this')}"
2721
2722    def set_operation(self, expression: exp.Union, op: str) -> str:
2723        this = self.maybe_comment(self.sql(expression, "this"), comments=expression.comments)
2724        op = self.seg(op)
2725        return self.query_modifiers(
2726            expression, f"{this}{op}{self.sep()}{self.sql(expression, 'expression')}"
2727        )
2728
2729    def tag_sql(self, expression: exp.Tag) -> str:
2730        return f"{expression.args.get('prefix')}{self.sql(expression.this)}{expression.args.get('postfix')}"
2731
2732    def token_sql(self, token_type: TokenType) -> str:
2733        return self.TOKEN_MAPPING.get(token_type, token_type.name)
2734
2735    def userdefinedfunction_sql(self, expression: exp.UserDefinedFunction) -> str:
2736        this = self.sql(expression, "this")
2737        expressions = self.no_identify(self.expressions, expression)
2738        expressions = (
2739            self.wrap(expressions) if expression.args.get("wrapped") else f" {expressions}"
2740        )
2741        return f"{this}{expressions}"
2742
2743    def joinhint_sql(self, expression: exp.JoinHint) -> str:
2744        this = self.sql(expression, "this")
2745        expressions = self.expressions(expression, flat=True)
2746        return f"{this}({expressions})"
2747
2748    def kwarg_sql(self, expression: exp.Kwarg) -> str:
2749        return self.binary(expression, "=>")
2750
2751    def when_sql(self, expression: exp.When) -> str:
2752        matched = "MATCHED" if expression.args["matched"] else "NOT MATCHED"
2753        source = " BY SOURCE" if self.MATCHED_BY_SOURCE and expression.args.get("source") else ""
2754        condition = self.sql(expression, "condition")
2755        condition = f" AND {condition}" if condition else ""
2756
2757        then_expression = expression.args.get("then")
2758        if isinstance(then_expression, exp.Insert):
2759            then = f"INSERT {self.sql(then_expression, 'this')}"
2760            if "expression" in then_expression.args:
2761                then += f" VALUES {self.sql(then_expression, 'expression')}"
2762        elif isinstance(then_expression, exp.Update):
2763            if isinstance(then_expression.args.get("expressions"), exp.Star):
2764                then = f"UPDATE {self.sql(then_expression, 'expressions')}"
2765            else:
2766                then = f"UPDATE SET {self.expressions(then_expression, flat=True)}"
2767        else:
2768            then = self.sql(then_expression)
2769        return f"WHEN {matched}{source}{condition} THEN {then}"
2770
2771    def merge_sql(self, expression: exp.Merge) -> str:
2772        table = expression.this
2773        table_alias = ""
2774
2775        hints = table.args.get("hints")
2776        if hints and table.alias and isinstance(hints[0], exp.WithTableHint):
2777            # T-SQL syntax is MERGE ... <target_table> [WITH (<merge_hint>)] [[AS] table_alias]
2778            table = table.copy()
2779            table_alias = f" AS {self.sql(table.args['alias'].pop())}"
2780
2781        this = self.sql(table)
2782        using = f"USING {self.sql(expression, 'using')}"
2783        on = f"ON {self.sql(expression, 'on')}"
2784        expressions = self.expressions(expression, sep=" ")
2785
2786        return f"MERGE INTO {this}{table_alias} {using} {on} {expressions}"
2787
2788    def tochar_sql(self, expression: exp.ToChar) -> str:
2789        if expression.args.get("format"):
2790            self.unsupported("Format argument unsupported for TO_CHAR/TO_VARCHAR function")
2791
2792        return self.sql(exp.cast(expression.this, "text"))
2793
2794    def dictproperty_sql(self, expression: exp.DictProperty) -> str:
2795        this = self.sql(expression, "this")
2796        kind = self.sql(expression, "kind")
2797        settings_sql = self.expressions(expression, key="settings", sep=" ")
2798        args = f"({self.sep('')}{settings_sql}{self.seg(')', sep='')}" if settings_sql else "()"
2799        return f"{this}({kind}{args})"
2800
2801    def dictrange_sql(self, expression: exp.DictRange) -> str:
2802        this = self.sql(expression, "this")
2803        max = self.sql(expression, "max")
2804        min = self.sql(expression, "min")
2805        return f"{this}(MIN {min} MAX {max})"
2806
2807    def dictsubproperty_sql(self, expression: exp.DictSubProperty) -> str:
2808        return f"{self.sql(expression, 'this')} {self.sql(expression, 'value')}"
2809
2810    def oncluster_sql(self, expression: exp.OnCluster) -> str:
2811        return ""
2812
2813    def clusteredbyproperty_sql(self, expression: exp.ClusteredByProperty) -> str:
2814        expressions = self.expressions(expression, key="expressions", flat=True)
2815        sorted_by = self.expressions(expression, key="sorted_by", flat=True)
2816        sorted_by = f" SORTED BY ({sorted_by})" if sorted_by else ""
2817        buckets = self.sql(expression, "buckets")
2818        return f"CLUSTERED BY ({expressions}){sorted_by} INTO {buckets} BUCKETS"
2819
2820    def anyvalue_sql(self, expression: exp.AnyValue) -> str:
2821        this = self.sql(expression, "this")
2822        having = self.sql(expression, "having")
2823
2824        if having:
2825            this = f"{this} HAVING {'MAX' if expression.args.get('max') else 'MIN'} {having}"
2826
2827        return self.func("ANY_VALUE", this)
2828
2829    def querytransform_sql(self, expression: exp.QueryTransform) -> str:
2830        transform = self.func("TRANSFORM", *expression.expressions)
2831        row_format_before = self.sql(expression, "row_format_before")
2832        row_format_before = f" {row_format_before}" if row_format_before else ""
2833        record_writer = self.sql(expression, "record_writer")
2834        record_writer = f" RECORDWRITER {record_writer}" if record_writer else ""
2835        using = f" USING {self.sql(expression, 'command_script')}"
2836        schema = self.sql(expression, "schema")
2837        schema = f" AS {schema}" if schema else ""
2838        row_format_after = self.sql(expression, "row_format_after")
2839        row_format_after = f" {row_format_after}" if row_format_after else ""
2840        record_reader = self.sql(expression, "record_reader")
2841        record_reader = f" RECORDREADER {record_reader}" if record_reader else ""
2842        return f"{transform}{row_format_before}{record_writer}{using}{schema}{row_format_after}{record_reader}"
2843
2844    def indexconstraintoption_sql(self, expression: exp.IndexConstraintOption) -> str:
2845        key_block_size = self.sql(expression, "key_block_size")
2846        if key_block_size:
2847            return f"KEY_BLOCK_SIZE = {key_block_size}"
2848
2849        using = self.sql(expression, "using")
2850        if using:
2851            return f"USING {using}"
2852
2853        parser = self.sql(expression, "parser")
2854        if parser:
2855            return f"WITH PARSER {parser}"
2856
2857        comment = self.sql(expression, "comment")
2858        if comment:
2859            return f"COMMENT {comment}"
2860
2861        visible = expression.args.get("visible")
2862        if visible is not None:
2863            return "VISIBLE" if visible else "INVISIBLE"
2864
2865        engine_attr = self.sql(expression, "engine_attr")
2866        if engine_attr:
2867            return f"ENGINE_ATTRIBUTE = {engine_attr}"
2868
2869        secondary_engine_attr = self.sql(expression, "secondary_engine_attr")
2870        if secondary_engine_attr:
2871            return f"SECONDARY_ENGINE_ATTRIBUTE = {secondary_engine_attr}"
2872
2873        self.unsupported("Unsupported index constraint option.")
2874        return ""
2875
2876    def indexcolumnconstraint_sql(self, expression: exp.IndexColumnConstraint) -> str:
2877        kind = self.sql(expression, "kind")
2878        kind = f"{kind} INDEX" if kind else "INDEX"
2879        this = self.sql(expression, "this")
2880        this = f" {this}" if this else ""
2881        index_type = self.sql(expression, "index_type")
2882        index_type = f" USING {index_type}" if index_type else ""
2883        schema = self.sql(expression, "schema")
2884        schema = f" {schema}" if schema else ""
2885        options = self.expressions(expression, key="options", sep=" ")
2886        options = f" {options}" if options else ""
2887        return f"{kind}{this}{index_type}{schema}{options}"
2888
2889    def nvl2_sql(self, expression: exp.Nvl2) -> str:
2890        if self.NVL2_SUPPORTED:
2891            return self.function_fallback_sql(expression)
2892
2893        case = exp.Case().when(
2894            expression.this.is_(exp.null()).not_(copy=False),
2895            expression.args["true"].copy(),
2896            copy=False,
2897        )
2898        else_cond = expression.args.get("false")
2899        if else_cond:
2900            case.else_(else_cond.copy(), copy=False)
2901
2902        return self.sql(case)
2903
2904    def comprehension_sql(self, expression: exp.Comprehension) -> str:
2905        this = self.sql(expression, "this")
2906        expr = self.sql(expression, "expression")
2907        iterator = self.sql(expression, "iterator")
2908        condition = self.sql(expression, "condition")
2909        condition = f" IF {condition}" if condition else ""
2910        return f"{this} FOR {expr} IN {iterator}{condition}"
2911
2912    def columnprefix_sql(self, expression: exp.ColumnPrefix) -> str:
2913        return f"{self.sql(expression, 'this')}({self.sql(expression, 'expression')})"
2914
2915    def opclass_sql(self, expression: exp.Opclass) -> str:
2916        return f"{self.sql(expression, 'this')} {self.sql(expression, 'expression')}"
2917
2918    def predict_sql(self, expression: exp.Predict) -> str:
2919        model = self.sql(expression, "this")
2920        model = f"MODEL {model}"
2921        table = self.sql(expression, "expression")
2922        table = f"TABLE {table}" if not isinstance(expression.expression, exp.Subquery) else table
2923        parameters = self.sql(expression, "params_struct")
2924        return self.func("PREDICT", model, table, parameters or None)
2925
2926    def _simplify_unless_literal(self, expression: E) -> E:
2927        if not isinstance(expression, exp.Literal):
2928            from sqlglot.optimizer.simplify import simplify
2929
2930            expression = simplify(expression.copy())
2931
2932        return expression
2933
2934
2935def cached_generator(
2936    cache: t.Optional[t.Dict[int, str]] = None
2937) -> t.Callable[[exp.Expression], str]:
2938    """Returns a cached generator."""
2939    cache = {} if cache is None else cache
2940    generator = Generator(normalize=True, identify="safe")
2941    return lambda e: generator.generate(e, cache)