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sqlglot.dialects.snowflake

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  1from __future__ import annotations
  2
  3from sqlglot import exp, generator, parser, tokens
  4from sqlglot.dialects.dialect import (
  5    Dialect,
  6    datestrtodate_sql,
  7    format_time_lambda,
  8    inline_array_sql,
  9    rename_func,
 10    timestrtotime_sql,
 11    var_map_sql,
 12)
 13from sqlglot.expressions import Literal
 14from sqlglot.helper import flatten, seq_get
 15from sqlglot.tokens import TokenType
 16
 17
 18def _check_int(s):
 19    if s[0] in ("-", "+"):
 20        return s[1:].isdigit()
 21    return s.isdigit()
 22
 23
 24# from https://docs.snowflake.com/en/sql-reference/functions/to_timestamp.html
 25def _snowflake_to_timestamp(args):
 26    if len(args) == 2:
 27        first_arg, second_arg = args
 28        if second_arg.is_string:
 29            # case: <string_expr> [ , <format> ]
 30            return format_time_lambda(exp.StrToTime, "snowflake")(args)
 31
 32        # case: <numeric_expr> [ , <scale> ]
 33        if second_arg.name not in ["0", "3", "9"]:
 34            raise ValueError(
 35                f"Scale for snowflake numeric timestamp is {second_arg}, but should be 0, 3, or 9"
 36            )
 37
 38        if second_arg.name == "0":
 39            timescale = exp.UnixToTime.SECONDS
 40        elif second_arg.name == "3":
 41            timescale = exp.UnixToTime.MILLIS
 42        elif second_arg.name == "9":
 43            timescale = exp.UnixToTime.MICROS
 44
 45        return exp.UnixToTime(this=first_arg, scale=timescale)
 46
 47    first_arg = seq_get(args, 0)
 48    if not isinstance(first_arg, Literal):
 49        # case: <variant_expr>
 50        return format_time_lambda(exp.StrToTime, "snowflake", default=True)(args)
 51
 52    if first_arg.is_string:
 53        if _check_int(first_arg.this):
 54            # case: <integer>
 55            return exp.UnixToTime.from_arg_list(args)
 56
 57        # case: <date_expr>
 58        return format_time_lambda(exp.StrToTime, "snowflake", default=True)(args)
 59
 60    # case: <numeric_expr>
 61    return exp.UnixToTime.from_arg_list(args)
 62
 63
 64def _unix_to_time_sql(self, expression):
 65    scale = expression.args.get("scale")
 66    timestamp = self.sql(expression, "this")
 67    if scale in [None, exp.UnixToTime.SECONDS]:
 68        return f"TO_TIMESTAMP({timestamp})"
 69    if scale == exp.UnixToTime.MILLIS:
 70        return f"TO_TIMESTAMP({timestamp}, 3)"
 71    if scale == exp.UnixToTime.MICROS:
 72        return f"TO_TIMESTAMP({timestamp}, 9)"
 73
 74    raise ValueError("Improper scale for timestamp")
 75
 76
 77# https://docs.snowflake.com/en/sql-reference/functions/date_part.html
 78# https://docs.snowflake.com/en/sql-reference/functions-date-time.html#label-supported-date-time-parts
 79def _parse_date_part(self):
 80    this = self._parse_var() or self._parse_type()
 81    self._match(TokenType.COMMA)
 82    expression = self._parse_bitwise()
 83
 84    name = this.name.upper()
 85    if name.startswith("EPOCH"):
 86        if name.startswith("EPOCH_MILLISECOND"):
 87            scale = 10**3
 88        elif name.startswith("EPOCH_MICROSECOND"):
 89            scale = 10**6
 90        elif name.startswith("EPOCH_NANOSECOND"):
 91            scale = 10**9
 92        else:
 93            scale = None
 94
 95        ts = self.expression(exp.Cast, this=expression, to=exp.DataType.build("TIMESTAMP"))
 96        to_unix = self.expression(exp.TimeToUnix, this=ts)
 97
 98        if scale:
 99            to_unix = exp.Mul(this=to_unix, expression=exp.Literal.number(scale))
100
101        return to_unix
102
103    return self.expression(exp.Extract, this=this, expression=expression)
104
105
106def _datatype_sql(self, expression):
107    if expression.this == exp.DataType.Type.ARRAY:
108        return "ARRAY"
109    elif expression.this == exp.DataType.Type.MAP:
110        return "OBJECT"
111    return self.datatype_sql(expression)
112
113
114class Snowflake(Dialect):
115    null_ordering = "nulls_are_large"
116    time_format = "'yyyy-mm-dd hh24:mi:ss'"
117
118    time_mapping = {
119        "YYYY": "%Y",
120        "yyyy": "%Y",
121        "YY": "%y",
122        "yy": "%y",
123        "MMMM": "%B",
124        "mmmm": "%B",
125        "MON": "%b",
126        "mon": "%b",
127        "MM": "%m",
128        "mm": "%m",
129        "DD": "%d",
130        "dd": "%d",
131        "d": "%-d",
132        "DY": "%w",
133        "dy": "%w",
134        "HH24": "%H",
135        "hh24": "%H",
136        "HH12": "%I",
137        "hh12": "%I",
138        "MI": "%M",
139        "mi": "%M",
140        "SS": "%S",
141        "ss": "%S",
142        "FF": "%f",
143        "ff": "%f",
144        "FF6": "%f",
145        "ff6": "%f",
146    }
147
148    class Parser(parser.Parser):
149        FUNCTIONS = {
150            **parser.Parser.FUNCTIONS,
151            "ARRAYAGG": exp.ArrayAgg.from_arg_list,
152            "IFF": exp.If.from_arg_list,
153            "TO_TIMESTAMP": _snowflake_to_timestamp,
154            "ARRAY_CONSTRUCT": exp.Array.from_arg_list,
155            "RLIKE": exp.RegexpLike.from_arg_list,
156            "DECODE": exp.Matches.from_arg_list,
157            "OBJECT_CONSTRUCT": parser.parse_var_map,
158        }
159
160        FUNCTION_PARSERS = {
161            **parser.Parser.FUNCTION_PARSERS,
162            "DATE_PART": _parse_date_part,
163        }
164        FUNCTION_PARSERS.pop("TRIM")
165
166        FUNC_TOKENS = {
167            *parser.Parser.FUNC_TOKENS,
168            TokenType.RLIKE,
169            TokenType.TABLE,
170        }
171
172        COLUMN_OPERATORS = {
173            **parser.Parser.COLUMN_OPERATORS,  # type: ignore
174            TokenType.COLON: lambda self, this, path: self.expression(
175                exp.Bracket,
176                this=this,
177                expressions=[path],
178            ),
179        }
180
181    class Tokenizer(tokens.Tokenizer):
182        QUOTES = ["'", "$$"]
183        STRING_ESCAPES = ["\\", "'"]
184
185        SINGLE_TOKENS = {
186            **tokens.Tokenizer.SINGLE_TOKENS,
187            "$": TokenType.PARAMETER,
188        }
189
190        KEYWORDS = {
191            **tokens.Tokenizer.KEYWORDS,
192            "EXCLUDE": TokenType.EXCEPT,
193            "MATCH_RECOGNIZE": TokenType.MATCH_RECOGNIZE,
194            "PUT": TokenType.COMMAND,
195            "RENAME": TokenType.REPLACE,
196            "TIMESTAMP_LTZ": TokenType.TIMESTAMPLTZ,
197            "TIMESTAMP_NTZ": TokenType.TIMESTAMP,
198            "TIMESTAMP_TZ": TokenType.TIMESTAMPTZ,
199            "TIMESTAMPNTZ": TokenType.TIMESTAMP,
200            "MINUS": TokenType.EXCEPT,
201            "SAMPLE": TokenType.TABLE_SAMPLE,
202        }
203
204    class Generator(generator.Generator):
205        CREATE_TRANSIENT = True
206
207        TRANSFORMS = {
208            **generator.Generator.TRANSFORMS,  # type: ignore
209            exp.Array: inline_array_sql,
210            exp.ArrayConcat: rename_func("ARRAY_CAT"),
211            exp.DateAdd: rename_func("DATEADD"),
212            exp.DateStrToDate: datestrtodate_sql,
213            exp.DataType: _datatype_sql,
214            exp.If: rename_func("IFF"),
215            exp.Map: lambda self, e: var_map_sql(self, e, "OBJECT_CONSTRUCT"),
216            exp.VarMap: lambda self, e: var_map_sql(self, e, "OBJECT_CONSTRUCT"),
217            exp.Parameter: lambda self, e: f"${self.sql(e, 'this')}",
218            exp.PartitionedByProperty: lambda self, e: f"PARTITION BY {self.sql(e, 'this')}",
219            exp.Matches: rename_func("DECODE"),
220            exp.StrPosition: lambda self, e: f"{self.normalize_func('POSITION')}({self.format_args(e.args.get('substr'), e.this, e.args.get('position'))})",
221            exp.StrToTime: lambda self, e: f"TO_TIMESTAMP({self.sql(e, 'this')}, {self.format_time(e)})",
222            exp.TimeStrToTime: timestrtotime_sql,
223            exp.TimeToUnix: lambda self, e: f"EXTRACT(epoch_second FROM {self.sql(e, 'this')})",
224            exp.Trim: lambda self, e: f"TRIM({self.format_args(e.this, e.expression)})",
225            exp.UnixToTime: _unix_to_time_sql,
226            exp.DayOfWeek: rename_func("DAYOFWEEK"),
227        }
228
229        TYPE_MAPPING = {
230            **generator.Generator.TYPE_MAPPING,  # type: ignore
231            exp.DataType.Type.TIMESTAMP: "TIMESTAMPNTZ",
232        }
233
234        STAR_MAPPING = {
235            "except": "EXCLUDE",
236            "replace": "RENAME",
237        }
238
239        def except_op(self, expression):
240            if not expression.args.get("distinct", False):
241                self.unsupported("EXCEPT with All is not supported in Snowflake")
242            return super().except_op(expression)
243
244        def intersect_op(self, expression):
245            if not expression.args.get("distinct", False):
246                self.unsupported("INTERSECT with All is not supported in Snowflake")
247            return super().intersect_op(expression)
248
249        def values_sql(self, expression: exp.Values) -> str:
250            """Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted.
251
252            We also want to make sure that after we find matches where we need to unquote a column that we prevent users
253            from adding quotes to the column by using the `identify` argument when generating the SQL.
254            """
255            alias = expression.args.get("alias")
256            if alias and alias.args.get("columns"):
257                expression = expression.transform(
258                    lambda node: exp.Identifier(**{**node.args, "quoted": False})
259                    if isinstance(node, exp.Identifier)
260                    and isinstance(node.parent, exp.TableAlias)
261                    and node.arg_key == "columns"
262                    else node,
263                )
264                return self.no_identify(lambda: super(self.__class__, self).values_sql(expression))
265            return super().values_sql(expression)
266
267        def select_sql(self, expression: exp.Select) -> str:
268            """Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted and also
269            that all columns in a SELECT are unquoted. We also want to make sure that after we find matches where we need
270            to unquote a column that we prevent users from adding quotes to the column by using the `identify` argument when
271            generating the SQL.
272
273            Note: We make an assumption that any columns referenced in a VALUES expression should be unquoted throughout the
274            expression. This might not be true in a case where the same column name can be sourced from another table that can
275            properly quote but should be true in most cases.
276            """
277            values_expressions = expression.find_all(exp.Values)
278            values_identifiers = set(
279                flatten(
280                    v.args.get("alias", exp.Alias()).args.get("columns", [])
281                    for v in values_expressions
282                )
283            )
284            if values_identifiers:
285                expression = expression.transform(
286                    lambda node: exp.Identifier(**{**node.args, "quoted": False})
287                    if isinstance(node, exp.Identifier) and node in values_identifiers
288                    else node,
289                )
290                return self.no_identify(lambda: super(self.__class__, self).select_sql(expression))
291            return super().select_sql(expression)
292
293        def describe_sql(self, expression: exp.Describe) -> str:
294            # Default to table if kind is unknown
295            kind_value = expression.args.get("kind") or "TABLE"
296            kind = f" {kind_value}" if kind_value else ""
297            this = f" {self.sql(expression, 'this')}"
298            return f"DESCRIBE{kind}{this}"
299
300        def generatedasidentitycolumnconstraint_sql(
301            self, expression: exp.GeneratedAsIdentityColumnConstraint
302        ) -> str:
303            start = expression.args.get("start")
304            start = f" START {start}" if start else ""
305            increment = expression.args.get("increment")
306            increment = f" INCREMENT {increment}" if increment else ""
307            return f"AUTOINCREMENT{start}{increment}"

class Snowflake(sqlglot.dialects.dialect.Dialect): View Source

115class Snowflake(Dialect):
116    null_ordering = "nulls_are_large"
117    time_format = "'yyyy-mm-dd hh24:mi:ss'"
118
119    time_mapping = {
120        "YYYY": "%Y",
121        "yyyy": "%Y",
122        "YY": "%y",
123        "yy": "%y",
124        "MMMM": "%B",
125        "mmmm": "%B",
126        "MON": "%b",
127        "mon": "%b",
128        "MM": "%m",
129        "mm": "%m",
130        "DD": "%d",
131        "dd": "%d",
132        "d": "%-d",
133        "DY": "%w",
134        "dy": "%w",
135        "HH24": "%H",
136        "hh24": "%H",
137        "HH12": "%I",
138        "hh12": "%I",
139        "MI": "%M",
140        "mi": "%M",
141        "SS": "%S",
142        "ss": "%S",
143        "FF": "%f",
144        "ff": "%f",
145        "FF6": "%f",
146        "ff6": "%f",
147    }
148
149    class Parser(parser.Parser):
150        FUNCTIONS = {
151            **parser.Parser.FUNCTIONS,
152            "ARRAYAGG": exp.ArrayAgg.from_arg_list,
153            "IFF": exp.If.from_arg_list,
154            "TO_TIMESTAMP": _snowflake_to_timestamp,
155            "ARRAY_CONSTRUCT": exp.Array.from_arg_list,
156            "RLIKE": exp.RegexpLike.from_arg_list,
157            "DECODE": exp.Matches.from_arg_list,
158            "OBJECT_CONSTRUCT": parser.parse_var_map,
159        }
160
161        FUNCTION_PARSERS = {
162            **parser.Parser.FUNCTION_PARSERS,
163            "DATE_PART": _parse_date_part,
164        }
165        FUNCTION_PARSERS.pop("TRIM")
166
167        FUNC_TOKENS = {
168            *parser.Parser.FUNC_TOKENS,
169            TokenType.RLIKE,
170            TokenType.TABLE,
171        }
172
173        COLUMN_OPERATORS = {
174            **parser.Parser.COLUMN_OPERATORS,  # type: ignore
175            TokenType.COLON: lambda self, this, path: self.expression(
176                exp.Bracket,
177                this=this,
178                expressions=[path],
179            ),
180        }
181
182    class Tokenizer(tokens.Tokenizer):
183        QUOTES = ["'", "$$"]
184        STRING_ESCAPES = ["\\", "'"]
185
186        SINGLE_TOKENS = {
187            **tokens.Tokenizer.SINGLE_TOKENS,
188            "$": TokenType.PARAMETER,
189        }
190
191        KEYWORDS = {
192            **tokens.Tokenizer.KEYWORDS,
193            "EXCLUDE": TokenType.EXCEPT,
194            "MATCH_RECOGNIZE": TokenType.MATCH_RECOGNIZE,
195            "PUT": TokenType.COMMAND,
196            "RENAME": TokenType.REPLACE,
197            "TIMESTAMP_LTZ": TokenType.TIMESTAMPLTZ,
198            "TIMESTAMP_NTZ": TokenType.TIMESTAMP,
199            "TIMESTAMP_TZ": TokenType.TIMESTAMPTZ,
200            "TIMESTAMPNTZ": TokenType.TIMESTAMP,
201            "MINUS": TokenType.EXCEPT,
202            "SAMPLE": TokenType.TABLE_SAMPLE,
203        }
204
205    class Generator(generator.Generator):
206        CREATE_TRANSIENT = True
207
208        TRANSFORMS = {
209            **generator.Generator.TRANSFORMS,  # type: ignore
210            exp.Array: inline_array_sql,
211            exp.ArrayConcat: rename_func("ARRAY_CAT"),
212            exp.DateAdd: rename_func("DATEADD"),
213            exp.DateStrToDate: datestrtodate_sql,
214            exp.DataType: _datatype_sql,
215            exp.If: rename_func("IFF"),
216            exp.Map: lambda self, e: var_map_sql(self, e, "OBJECT_CONSTRUCT"),
217            exp.VarMap: lambda self, e: var_map_sql(self, e, "OBJECT_CONSTRUCT"),
218            exp.Parameter: lambda self, e: f"${self.sql(e, 'this')}",
219            exp.PartitionedByProperty: lambda self, e: f"PARTITION BY {self.sql(e, 'this')}",
220            exp.Matches: rename_func("DECODE"),
221            exp.StrPosition: lambda self, e: f"{self.normalize_func('POSITION')}({self.format_args(e.args.get('substr'), e.this, e.args.get('position'))})",
222            exp.StrToTime: lambda self, e: f"TO_TIMESTAMP({self.sql(e, 'this')}, {self.format_time(e)})",
223            exp.TimeStrToTime: timestrtotime_sql,
224            exp.TimeToUnix: lambda self, e: f"EXTRACT(epoch_second FROM {self.sql(e, 'this')})",
225            exp.Trim: lambda self, e: f"TRIM({self.format_args(e.this, e.expression)})",
226            exp.UnixToTime: _unix_to_time_sql,
227            exp.DayOfWeek: rename_func("DAYOFWEEK"),
228        }
229
230        TYPE_MAPPING = {
231            **generator.Generator.TYPE_MAPPING,  # type: ignore
232            exp.DataType.Type.TIMESTAMP: "TIMESTAMPNTZ",
233        }
234
235        STAR_MAPPING = {
236            "except": "EXCLUDE",
237            "replace": "RENAME",
238        }
239
240        def except_op(self, expression):
241            if not expression.args.get("distinct", False):
242                self.unsupported("EXCEPT with All is not supported in Snowflake")
243            return super().except_op(expression)
244
245        def intersect_op(self, expression):
246            if not expression.args.get("distinct", False):
247                self.unsupported("INTERSECT with All is not supported in Snowflake")
248            return super().intersect_op(expression)
249
250        def values_sql(self, expression: exp.Values) -> str:
251            """Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted.
252
253            We also want to make sure that after we find matches where we need to unquote a column that we prevent users
254            from adding quotes to the column by using the `identify` argument when generating the SQL.
255            """
256            alias = expression.args.get("alias")
257            if alias and alias.args.get("columns"):
258                expression = expression.transform(
259                    lambda node: exp.Identifier(**{**node.args, "quoted": False})
260                    if isinstance(node, exp.Identifier)
261                    and isinstance(node.parent, exp.TableAlias)
262                    and node.arg_key == "columns"
263                    else node,
264                )
265                return self.no_identify(lambda: super(self.__class__, self).values_sql(expression))
266            return super().values_sql(expression)
267
268        def select_sql(self, expression: exp.Select) -> str:
269            """Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted and also
270            that all columns in a SELECT are unquoted. We also want to make sure that after we find matches where we need
271            to unquote a column that we prevent users from adding quotes to the column by using the `identify` argument when
272            generating the SQL.
273
274            Note: We make an assumption that any columns referenced in a VALUES expression should be unquoted throughout the
275            expression. This might not be true in a case where the same column name can be sourced from another table that can
276            properly quote but should be true in most cases.
277            """
278            values_expressions = expression.find_all(exp.Values)
279            values_identifiers = set(
280                flatten(
281                    v.args.get("alias", exp.Alias()).args.get("columns", [])
282                    for v in values_expressions
283                )
284            )
285            if values_identifiers:
286                expression = expression.transform(
287                    lambda node: exp.Identifier(**{**node.args, "quoted": False})
288                    if isinstance(node, exp.Identifier) and node in values_identifiers
289                    else node,
290                )
291                return self.no_identify(lambda: super(self.__class__, self).select_sql(expression))
292            return super().select_sql(expression)
293
294        def describe_sql(self, expression: exp.Describe) -> str:
295            # Default to table if kind is unknown
296            kind_value = expression.args.get("kind") or "TABLE"
297            kind = f" {kind_value}" if kind_value else ""
298            this = f" {self.sql(expression, 'this')}"
299            return f"DESCRIBE{kind}{this}"
300
301        def generatedasidentitycolumnconstraint_sql(
302            self, expression: exp.GeneratedAsIdentityColumnConstraint
303        ) -> str:
304            start = expression.args.get("start")
305            start = f" START {start}" if start else ""
306            increment = expression.args.get("increment")
307            increment = f" INCREMENT {increment}" if increment else ""
308            return f"AUTOINCREMENT{start}{increment}"

Snowflake()

Inherited Members

sqlglot.dialects.dialect.Dialect: get_or_raise; format_time; parse; parse_into; generate; transpile; parser; generator

class Snowflake.Parser(sqlglot.parser.Parser): View Source

149    class Parser(parser.Parser):
150        FUNCTIONS = {
151            **parser.Parser.FUNCTIONS,
152            "ARRAYAGG": exp.ArrayAgg.from_arg_list,
153            "IFF": exp.If.from_arg_list,
154            "TO_TIMESTAMP": _snowflake_to_timestamp,
155            "ARRAY_CONSTRUCT": exp.Array.from_arg_list,
156            "RLIKE": exp.RegexpLike.from_arg_list,
157            "DECODE": exp.Matches.from_arg_list,
158            "OBJECT_CONSTRUCT": parser.parse_var_map,
159        }
160
161        FUNCTION_PARSERS = {
162            **parser.Parser.FUNCTION_PARSERS,
163            "DATE_PART": _parse_date_part,
164        }
165        FUNCTION_PARSERS.pop("TRIM")
166
167        FUNC_TOKENS = {
168            *parser.Parser.FUNC_TOKENS,
169            TokenType.RLIKE,
170            TokenType.TABLE,
171        }
172
173        COLUMN_OPERATORS = {
174            **parser.Parser.COLUMN_OPERATORS,  # type: ignore
175            TokenType.COLON: lambda self, this, path: self.expression(
176                exp.Bracket,
177                this=this,
178                expressions=[path],
179            ),
180        }

Parser consumes a list of tokens produced by the sqlglot.tokens.Tokenizer and produces a parsed syntax tree.

Arguments:

error_level: the desired error level. Default: ErrorLevel.RAISE
error_message_context: determines the amount of context to capture from a query string when displaying the error message (in number of characters). Default: 50.
index_offset: Index offset for arrays eg ARRAY[0] vs ARRAY[1] as the head of a list. Default: 0
alias_post_tablesample: If the table alias comes after tablesample. Default: False
max_errors: Maximum number of error messages to include in a raised ParseError. This is only relevant if error_level is ErrorLevel.RAISE. Default: 3
null_ordering: Indicates the default null ordering method to use if not explicitly set. Options are "nulls_are_small", "nulls_are_large", "nulls_are_last". Default: "nulls_are_small"

Inherited Members

sqlglot.parser.Parser: Parser; reset; parse; parse_into; check_errors; raise_error; expression; validate_expression

class Snowflake.Tokenizer(sqlglot.tokens.Tokenizer): View Source

182    class Tokenizer(tokens.Tokenizer):
183        QUOTES = ["'", "$$"]
184        STRING_ESCAPES = ["\\", "'"]
185
186        SINGLE_TOKENS = {
187            **tokens.Tokenizer.SINGLE_TOKENS,
188            "$": TokenType.PARAMETER,
189        }
190
191        KEYWORDS = {
192            **tokens.Tokenizer.KEYWORDS,
193            "EXCLUDE": TokenType.EXCEPT,
194            "MATCH_RECOGNIZE": TokenType.MATCH_RECOGNIZE,
195            "PUT": TokenType.COMMAND,
196            "RENAME": TokenType.REPLACE,
197            "TIMESTAMP_LTZ": TokenType.TIMESTAMPLTZ,
198            "TIMESTAMP_NTZ": TokenType.TIMESTAMP,
199            "TIMESTAMP_TZ": TokenType.TIMESTAMPTZ,
200            "TIMESTAMPNTZ": TokenType.TIMESTAMP,
201            "MINUS": TokenType.EXCEPT,
202            "SAMPLE": TokenType.TABLE_SAMPLE,
203        }

Inherited Members

sqlglot.tokens.Tokenizer: Tokenizer; reset; tokenize

class Snowflake.Generator(sqlglot.generator.Generator): View Source

205    class Generator(generator.Generator):
206        CREATE_TRANSIENT = True
207
208        TRANSFORMS = {
209            **generator.Generator.TRANSFORMS,  # type: ignore
210            exp.Array: inline_array_sql,
211            exp.ArrayConcat: rename_func("ARRAY_CAT"),
212            exp.DateAdd: rename_func("DATEADD"),
213            exp.DateStrToDate: datestrtodate_sql,
214            exp.DataType: _datatype_sql,
215            exp.If: rename_func("IFF"),
216            exp.Map: lambda self, e: var_map_sql(self, e, "OBJECT_CONSTRUCT"),
217            exp.VarMap: lambda self, e: var_map_sql(self, e, "OBJECT_CONSTRUCT"),
218            exp.Parameter: lambda self, e: f"${self.sql(e, 'this')}",
219            exp.PartitionedByProperty: lambda self, e: f"PARTITION BY {self.sql(e, 'this')}",
220            exp.Matches: rename_func("DECODE"),
221            exp.StrPosition: lambda self, e: f"{self.normalize_func('POSITION')}({self.format_args(e.args.get('substr'), e.this, e.args.get('position'))})",
222            exp.StrToTime: lambda self, e: f"TO_TIMESTAMP({self.sql(e, 'this')}, {self.format_time(e)})",
223            exp.TimeStrToTime: timestrtotime_sql,
224            exp.TimeToUnix: lambda self, e: f"EXTRACT(epoch_second FROM {self.sql(e, 'this')})",
225            exp.Trim: lambda self, e: f"TRIM({self.format_args(e.this, e.expression)})",
226            exp.UnixToTime: _unix_to_time_sql,
227            exp.DayOfWeek: rename_func("DAYOFWEEK"),
228        }
229
230        TYPE_MAPPING = {
231            **generator.Generator.TYPE_MAPPING,  # type: ignore
232            exp.DataType.Type.TIMESTAMP: "TIMESTAMPNTZ",
233        }
234
235        STAR_MAPPING = {
236            "except": "EXCLUDE",
237            "replace": "RENAME",
238        }
239
240        def except_op(self, expression):
241            if not expression.args.get("distinct", False):
242                self.unsupported("EXCEPT with All is not supported in Snowflake")
243            return super().except_op(expression)
244
245        def intersect_op(self, expression):
246            if not expression.args.get("distinct", False):
247                self.unsupported("INTERSECT with All is not supported in Snowflake")
248            return super().intersect_op(expression)
249
250        def values_sql(self, expression: exp.Values) -> str:
251            """Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted.
252
253            We also want to make sure that after we find matches where we need to unquote a column that we prevent users
254            from adding quotes to the column by using the `identify` argument when generating the SQL.
255            """
256            alias = expression.args.get("alias")
257            if alias and alias.args.get("columns"):
258                expression = expression.transform(
259                    lambda node: exp.Identifier(**{**node.args, "quoted": False})
260                    if isinstance(node, exp.Identifier)
261                    and isinstance(node.parent, exp.TableAlias)
262                    and node.arg_key == "columns"
263                    else node,
264                )
265                return self.no_identify(lambda: super(self.__class__, self).values_sql(expression))
266            return super().values_sql(expression)
267
268        def select_sql(self, expression: exp.Select) -> str:
269            """Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted and also
270            that all columns in a SELECT are unquoted. We also want to make sure that after we find matches where we need
271            to unquote a column that we prevent users from adding quotes to the column by using the `identify` argument when
272            generating the SQL.
273
274            Note: We make an assumption that any columns referenced in a VALUES expression should be unquoted throughout the
275            expression. This might not be true in a case where the same column name can be sourced from another table that can
276            properly quote but should be true in most cases.
277            """
278            values_expressions = expression.find_all(exp.Values)
279            values_identifiers = set(
280                flatten(
281                    v.args.get("alias", exp.Alias()).args.get("columns", [])
282                    for v in values_expressions
283                )
284            )
285            if values_identifiers:
286                expression = expression.transform(
287                    lambda node: exp.Identifier(**{**node.args, "quoted": False})
288                    if isinstance(node, exp.Identifier) and node in values_identifiers
289                    else node,
290                )
291                return self.no_identify(lambda: super(self.__class__, self).select_sql(expression))
292            return super().select_sql(expression)
293
294        def describe_sql(self, expression: exp.Describe) -> str:
295            # Default to table if kind is unknown
296            kind_value = expression.args.get("kind") or "TABLE"
297            kind = f" {kind_value}" if kind_value else ""
298            this = f" {self.sql(expression, 'this')}"
299            return f"DESCRIBE{kind}{this}"
300
301        def generatedasidentitycolumnconstraint_sql(
302            self, expression: exp.GeneratedAsIdentityColumnConstraint
303        ) -> str:
304            start = expression.args.get("start")
305            start = f" START {start}" if start else ""
306            increment = expression.args.get("increment")
307            increment = f" INCREMENT {increment}" if increment else ""
308            return f"AUTOINCREMENT{start}{increment}"

Generator interprets the given syntax tree and produces a SQL string as an output.

Arguments:

time_mapping (dict): the dictionary of custom time mappings in which the key represents a python time format and the output the target time format
time_trie (trie): a trie of the time_mapping keys
pretty (bool): if set to True the returned string will be formatted. Default: False.
quote_start (str): specifies which starting character to use to delimit quotes. Default: '.
quote_end (str): specifies which ending character to use to delimit quotes. Default: '.
identifier_start (str): specifies which starting character to use to delimit identifiers. Default: ".
identifier_end (str): specifies which ending character to use to delimit identifiers. Default: ".
identify (bool): if set to True all identifiers will be delimited by the corresponding character.
normalize (bool): if set to True all identifiers will lower cased
string_escape (str): specifies a string escape character. Default: '.
identifier_escape (str): specifies an identifier escape character. Default: ".
pad (int): determines padding in a formatted string. Default: 2.
indent (int): determines the size of indentation in a formatted string. Default: 4.
unnest_column_only (bool): if true unnest table aliases are considered only as column aliases
normalize_functions (str): normalize function names, "upper", "lower", or None Default: "upper"
alias_post_tablesample (bool): if the table alias comes after tablesample Default: False
unsupported_level (ErrorLevel): determines the generator's behavior when it encounters unsupported expressions. Default ErrorLevel.WARN.
null_ordering (str): Indicates the default null ordering method to use if not explicitly set. Options are "nulls_are_small", "nulls_are_large", "nulls_are_last". Default: "nulls_are_small"
max_unsupported (int): Maximum number of unsupported messages to include in a raised UnsupportedError. This is only relevant if unsupported_level is ErrorLevel.RAISE. Default: 3
leading_comma (bool): if the the comma is leading or trailing in select statements Default: False
max_text_width: The max number of characters in a segment before creating new lines in pretty mode. The default is on the smaller end because the length only represents a segment and not the true line length. Default: 80
comments: Whether or not to preserve comments in the output SQL code. Default: True

def except_op(self, expression): View Source

240        def except_op(self, expression):
241            if not expression.args.get("distinct", False):
242                self.unsupported("EXCEPT with All is not supported in Snowflake")
243            return super().except_op(expression)

def intersect_op(self, expression): View Source

245        def intersect_op(self, expression):
246            if not expression.args.get("distinct", False):
247                self.unsupported("INTERSECT with All is not supported in Snowflake")
248            return super().intersect_op(expression)

def values_sql(self, expression: sqlglot.expressions.Values) -> str: View Source

250        def values_sql(self, expression: exp.Values) -> str:
251            """Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted.
252
253            We also want to make sure that after we find matches where we need to unquote a column that we prevent users
254            from adding quotes to the column by using the `identify` argument when generating the SQL.
255            """
256            alias = expression.args.get("alias")
257            if alias and alias.args.get("columns"):
258                expression = expression.transform(
259                    lambda node: exp.Identifier(**{**node.args, "quoted": False})
260                    if isinstance(node, exp.Identifier)
261                    and isinstance(node.parent, exp.TableAlias)
262                    and node.arg_key == "columns"
263                    else node,
264                )
265                return self.no_identify(lambda: super(self.__class__, self).values_sql(expression))
266            return super().values_sql(expression)

Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted.

We also want to make sure that after we find matches where we need to unquote a column that we prevent users from adding quotes to the column by using the identify argument when generating the SQL.

def select_sql(self, expression: sqlglot.expressions.Select) -> str: View Source

268        def select_sql(self, expression: exp.Select) -> str:
269            """Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted and also
270            that all columns in a SELECT are unquoted. We also want to make sure that after we find matches where we need
271            to unquote a column that we prevent users from adding quotes to the column by using the `identify` argument when
272            generating the SQL.
273
274            Note: We make an assumption that any columns referenced in a VALUES expression should be unquoted throughout the
275            expression. This might not be true in a case where the same column name can be sourced from another table that can
276            properly quote but should be true in most cases.
277            """
278            values_expressions = expression.find_all(exp.Values)
279            values_identifiers = set(
280                flatten(
281                    v.args.get("alias", exp.Alias()).args.get("columns", [])
282                    for v in values_expressions
283                )
284            )
285            if values_identifiers:
286                expression = expression.transform(
287                    lambda node: exp.Identifier(**{**node.args, "quoted": False})
288                    if isinstance(node, exp.Identifier) and node in values_identifiers
289                    else node,
290                )
291                return self.no_identify(lambda: super(self.__class__, self).select_sql(expression))
292            return super().select_sql(expression)

Due to a bug in Snowflake we want to make sure that all columns in a VALUES table alias are unquoted and also that all columns in a SELECT are unquoted. We also want to make sure that after we find matches where we need to unquote a column that we prevent users from adding quotes to the column by using the identify argument when generating the SQL.

Note: We make an assumption that any columns referenced in a VALUES expression should be unquoted throughout the expression. This might not be true in a case where the same column name can be sourced from another table that can properly quote but should be true in most cases.

def describe_sql(self, expression: sqlglot.expressions.Describe) -> str: View Source

294        def describe_sql(self, expression: exp.Describe) -> str:
295            # Default to table if kind is unknown
296            kind_value = expression.args.get("kind") or "TABLE"
297            kind = f" {kind_value}" if kind_value else ""
298            this = f" {self.sql(expression, 'this')}"
299            return f"DESCRIBE{kind}{this}"

def generatedasidentitycolumnconstraint_sql( self, expression: sqlglot.expressions.GeneratedAsIdentityColumnConstraint) -> str: View Source

301        def generatedasidentitycolumnconstraint_sql(
302            self, expression: exp.GeneratedAsIdentityColumnConstraint
303        ) -> str:
304            start = expression.args.get("start")
305            start = f" START {start}" if start else ""
306            increment = expression.args.get("increment")
307            increment = f" INCREMENT {increment}" if increment else ""
308            return f"AUTOINCREMENT{start}{increment}"

Inherited Members

sqlglot.generator.Generator: Generator; generate; unsupported; sep; seg; pad_comment; maybe_comment; wrap; no_identify; normalize_func; indent; sql; uncache_sql; cache_sql; characterset_sql; column_sql; columndef_sql; columnconstraint_sql; autoincrementcolumnconstraint_sql; checkcolumnconstraint_sql; commentcolumnconstraint_sql; collatecolumnconstraint_sql; encodecolumnconstraint_sql; defaultcolumnconstraint_sql; notnullcolumnconstraint_sql; primarykeycolumnconstraint_sql; uniquecolumnconstraint_sql; create_sql; prepend_ctes; with_sql; cte_sql; tablealias_sql; bitstring_sql; hexstring_sql; datatype_sql; directory_sql; delete_sql; drop_sql; except_sql; fetch_sql; filter_sql; hint_sql; index_sql; identifier_sql; national_sql; partition_sql; properties_sql; root_properties; properties; with_properties; locate_properties; property_sql; likeproperty_sql; fallbackproperty_sql; journalproperty_sql; freespaceproperty_sql; afterjournalproperty_sql; checksumproperty_sql; mergeblockratioproperty_sql; datablocksizeproperty_sql; blockcompressionproperty_sql; isolatedloadingproperty_sql; insert_sql; intersect_sql; introducer_sql; pseudotype_sql; rowformatdelimitedproperty_sql; table_sql; tablesample_sql; pivot_sql; tuple_sql; update_sql; var_sql; into_sql; from_sql; group_sql; having_sql; join_sql; lambda_sql; lateral_sql; limit_sql; offset_sql; lock_sql; literal_sql; loaddata_sql; null_sql; boolean_sql; order_sql; cluster_sql; distribute_sql; sort_sql; ordered_sql; matchrecognize_sql; query_modifiers; schema_sql; star_sql; structkwarg_sql; parameter_sql; sessionparameter_sql; placeholder_sql; subquery_sql; qualify_sql; union_sql; union_op; unnest_sql; where_sql; window_sql; partition_by_sql; window_spec_sql; withingroup_sql; between_sql; bracket_sql; all_sql; any_sql; exists_sql; case_sql; constraint_sql; extract_sql; trim_sql; concat_sql; check_sql; foreignkey_sql; primarykey_sql; unique_sql; if_sql; in_sql; in_unnest_op; interval_sql; return_sql; reference_sql; anonymous_sql; paren_sql; neg_sql; not_sql; alias_sql; aliases_sql; attimezone_sql; add_sql; and_sql; connector_sql; bitwiseand_sql; bitwiseleftshift_sql; bitwisenot_sql; bitwiseor_sql; bitwiserightshift_sql; bitwisexor_sql; cast_sql; currentdate_sql; collate_sql; command_sql; transaction_sql; commit_sql; rollback_sql; altercolumn_sql; renametable_sql; altertable_sql; droppartition_sql; addconstraint_sql; distinct_sql; ignorenulls_sql; respectnulls_sql; intdiv_sql; dpipe_sql; div_sql; distance_sql; dot_sql; eq_sql; escape_sql; glob_sql; gt_sql; gte_sql; ilike_sql; is_sql; like_sql; similarto_sql; lt_sql; lte_sql; mod_sql; mul_sql; neq_sql; nullsafeeq_sql; nullsafeneq_sql; or_sql; slice_sql; sub_sql; trycast_sql; use_sql; binary; function_fallback_sql; format_args; text_width; format_time; expressions; op_expressions; naked_property; set_operation; tag_sql; token_sql; userdefinedfunction_sql; userdefinedfunctionkwarg_sql; joinhint_sql; kwarg_sql; when_sql; merge_sql