sqlglot.dialects.snowflake API documentation

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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