sqlglot.generator

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