sqlglot.dialects.duckdb

   1from __future__ import annotations
   2
   3import typing as t
   4
   5from sqlglot import exp, generator, parser, tokens, transforms
   6from sqlglot.expressions import DATA_TYPE
   7from sqlglot.dialects.dialect import (
   8    Dialect,
   9    JSON_EXTRACT_TYPE,
  10    NormalizationStrategy,
  11    approx_count_distinct_sql,
  12    arrow_json_extract_sql,
  13    binary_from_function,
  14    bool_xor_sql,
  15    build_default_decimal_type,
  16    date_trunc_to_time,
  17    datestrtodate_sql,
  18    no_datetime_sql,
  19    encode_decode_sql,
  20    build_formatted_time,
  21    inline_array_unless_query,
  22    no_comment_column_constraint_sql,
  23    no_safe_divide_sql,
  24    no_time_sql,
  25    no_timestamp_sql,
  26    pivot_column_names,
  27    rename_func,
  28    str_position_sql,
  29    str_to_time_sql,
  30    timestamptrunc_sql,
  31    timestrtotime_sql,
  32    unit_to_var,
  33    unit_to_str,
  34    sha256_sql,
  35    build_regexp_extract,
  36    explode_to_unnest_sql,
  37    no_make_interval_sql,
  38)
  39from sqlglot.generator import unsupported_args
  40from sqlglot.helper import seq_get
  41from sqlglot.tokens import TokenType
  42from sqlglot.parser import binary_range_parser
  43
  44DATETIME_DELTA = t.Union[
  45    exp.DateAdd, exp.TimeAdd, exp.DatetimeAdd, exp.TsOrDsAdd, exp.DateSub, exp.DatetimeSub
  46]
  47
  48WINDOW_FUNCS_WITH_IGNORE_NULLS = (
  49    exp.FirstValue,
  50    exp.LastValue,
  51    exp.Lag,
  52    exp.Lead,
  53    exp.NthValue,
  54)
  55
  56
  57def _date_delta_sql(self: DuckDB.Generator, expression: DATETIME_DELTA) -> str:
  58    this = expression.this
  59    unit = unit_to_var(expression)
  60    op = (
  61        "+"
  62        if isinstance(expression, (exp.DateAdd, exp.TimeAdd, exp.DatetimeAdd, exp.TsOrDsAdd))
  63        else "-"
  64    )
  65
  66    to_type: t.Optional[DATA_TYPE] = None
  67    if isinstance(expression, exp.TsOrDsAdd):
  68        to_type = expression.return_type
  69    elif this.is_string:
  70        # Cast string literals (i.e function parameters) to the appropriate type for +/- interval to work
  71        to_type = (
  72            exp.DataType.Type.DATETIME
  73            if isinstance(expression, (exp.DatetimeAdd, exp.DatetimeSub))
  74            else exp.DataType.Type.DATE
  75        )
  76
  77    this = exp.cast(this, to_type) if to_type else this
  78
  79    return f"{self.sql(this)} {op} {self.sql(exp.Interval(this=expression.expression, unit=unit))}"
  80
  81
  82# BigQuery -> DuckDB conversion for the DATE function
  83def _date_sql(self: DuckDB.Generator, expression: exp.Date) -> str:
  84    result = f"CAST({self.sql(expression, 'this')} AS DATE)"
  85    zone = self.sql(expression, "zone")
  86
  87    if zone:
  88        date_str = self.func("STRFTIME", result, "'%d/%m/%Y'")
  89        date_str = f"{date_str} || ' ' || {zone}"
  90
  91        # This will create a TIMESTAMP with time zone information
  92        result = self.func("STRPTIME", date_str, "'%d/%m/%Y %Z'")
  93
  94    return result
  95
  96
  97# BigQuery -> DuckDB conversion for the TIME_DIFF function
  98def _timediff_sql(self: DuckDB.Generator, expression: exp.TimeDiff) -> str:
  99    this = exp.cast(expression.this, exp.DataType.Type.TIME)
 100    expr = exp.cast(expression.expression, exp.DataType.Type.TIME)
 101
 102    # Although the 2 dialects share similar signatures, BQ seems to inverse
 103    # the sign of the result so the start/end time operands are flipped
 104    return self.func("DATE_DIFF", unit_to_str(expression), expr, this)
 105
 106
 107@unsupported_args(("expression", "DuckDB's ARRAY_SORT does not support a comparator."))
 108def _array_sort_sql(self: DuckDB.Generator, expression: exp.ArraySort) -> str:
 109    return self.func("ARRAY_SORT", expression.this)
 110
 111
 112def _sort_array_sql(self: DuckDB.Generator, expression: exp.SortArray) -> str:
 113    name = "ARRAY_REVERSE_SORT" if expression.args.get("asc") == exp.false() else "ARRAY_SORT"
 114    return self.func(name, expression.this)
 115
 116
 117def _build_sort_array_desc(args: t.List) -> exp.Expression:
 118    return exp.SortArray(this=seq_get(args, 0), asc=exp.false())
 119
 120
 121def _build_date_diff(args: t.List) -> exp.Expression:
 122    return exp.DateDiff(this=seq_get(args, 2), expression=seq_get(args, 1), unit=seq_get(args, 0))
 123
 124
 125def _build_generate_series(end_exclusive: bool = False) -> t.Callable[[t.List], exp.GenerateSeries]:
 126    def _builder(args: t.List) -> exp.GenerateSeries:
 127        # Check https://duckdb.org/docs/sql/functions/nested.html#range-functions
 128        if len(args) == 1:
 129            # DuckDB uses 0 as a default for the series' start when it's omitted
 130            args.insert(0, exp.Literal.number("0"))
 131
 132        gen_series = exp.GenerateSeries.from_arg_list(args)
 133        gen_series.set("is_end_exclusive", end_exclusive)
 134
 135        return gen_series
 136
 137    return _builder
 138
 139
 140def _build_make_timestamp(args: t.List) -> exp.Expression:
 141    if len(args) == 1:
 142        return exp.UnixToTime(this=seq_get(args, 0), scale=exp.UnixToTime.MICROS)
 143
 144    return exp.TimestampFromParts(
 145        year=seq_get(args, 0),
 146        month=seq_get(args, 1),
 147        day=seq_get(args, 2),
 148        hour=seq_get(args, 3),
 149        min=seq_get(args, 4),
 150        sec=seq_get(args, 5),
 151    )
 152
 153
 154def _struct_sql(self: DuckDB.Generator, expression: exp.Struct) -> str:
 155    args: t.List[str] = []
 156
 157    # BigQuery allows inline construction such as "STRUCT<a STRING, b INTEGER>('str', 1)" which is
 158    # canonicalized to "ROW('str', 1) AS STRUCT(a TEXT, b INT)" in DuckDB
 159    # The transformation to ROW will take place if:
 160    #  1. The STRUCT itself does not have proper fields (key := value) as a "proper" STRUCT would
 161    #  2. A cast to STRUCT / ARRAY of STRUCTs is found
 162    ancestor_cast = expression.find_ancestor(exp.Cast)
 163    is_bq_inline_struct = (
 164        (expression.find(exp.PropertyEQ) is None)
 165        and ancestor_cast
 166        and any(
 167            casted_type.is_type(exp.DataType.Type.STRUCT)
 168            for casted_type in ancestor_cast.find_all(exp.DataType)
 169        )
 170    )
 171
 172    for i, expr in enumerate(expression.expressions):
 173        is_property_eq = isinstance(expr, exp.PropertyEQ)
 174        value = expr.expression if is_property_eq else expr
 175
 176        if is_bq_inline_struct:
 177            args.append(self.sql(value))
 178        else:
 179            key = expr.name if is_property_eq else f"_{i}"
 180            args.append(f"{self.sql(exp.Literal.string(key))}: {self.sql(value)}")
 181
 182    csv_args = ", ".join(args)
 183
 184    return f"ROW({csv_args})" if is_bq_inline_struct else f"{{{csv_args}}}"
 185
 186
 187def _datatype_sql(self: DuckDB.Generator, expression: exp.DataType) -> str:
 188    if expression.is_type("array"):
 189        return f"{self.expressions(expression, flat=True)}[{self.expressions(expression, key='values', flat=True)}]"
 190
 191    # Modifiers are not supported for TIME, [TIME | TIMESTAMP] WITH TIME ZONE
 192    if expression.is_type(
 193        exp.DataType.Type.TIME, exp.DataType.Type.TIMETZ, exp.DataType.Type.TIMESTAMPTZ
 194    ):
 195        return expression.this.value
 196
 197    return self.datatype_sql(expression)
 198
 199
 200def _json_format_sql(self: DuckDB.Generator, expression: exp.JSONFormat) -> str:
 201    sql = self.func("TO_JSON", expression.this, expression.args.get("options"))
 202    return f"CAST({sql} AS TEXT)"
 203
 204
 205def _unix_to_time_sql(self: DuckDB.Generator, expression: exp.UnixToTime) -> str:
 206    scale = expression.args.get("scale")
 207    timestamp = expression.this
 208
 209    if scale in (None, exp.UnixToTime.SECONDS):
 210        return self.func("TO_TIMESTAMP", timestamp)
 211    if scale == exp.UnixToTime.MILLIS:
 212        return self.func("EPOCH_MS", timestamp)
 213    if scale == exp.UnixToTime.MICROS:
 214        return self.func("MAKE_TIMESTAMP", timestamp)
 215
 216    return self.func("TO_TIMESTAMP", exp.Div(this=timestamp, expression=exp.func("POW", 10, scale)))
 217
 218
 219WRAPPED_JSON_EXTRACT_EXPRESSIONS = (exp.Binary, exp.Bracket, exp.In)
 220
 221
 222def _arrow_json_extract_sql(self: DuckDB.Generator, expression: JSON_EXTRACT_TYPE) -> str:
 223    arrow_sql = arrow_json_extract_sql(self, expression)
 224    if not expression.same_parent and isinstance(
 225        expression.parent, WRAPPED_JSON_EXTRACT_EXPRESSIONS
 226    ):
 227        arrow_sql = self.wrap(arrow_sql)
 228    return arrow_sql
 229
 230
 231def _implicit_datetime_cast(
 232    arg: t.Optional[exp.Expression], type: exp.DataType.Type = exp.DataType.Type.DATE
 233) -> t.Optional[exp.Expression]:
 234    return exp.cast(arg, type) if isinstance(arg, exp.Literal) else arg
 235
 236
 237def _date_diff_sql(self: DuckDB.Generator, expression: exp.DateDiff) -> str:
 238    this = _implicit_datetime_cast(expression.this)
 239    expr = _implicit_datetime_cast(expression.expression)
 240
 241    return self.func("DATE_DIFF", unit_to_str(expression), expr, this)
 242
 243
 244def _generate_datetime_array_sql(
 245    self: DuckDB.Generator, expression: t.Union[exp.GenerateDateArray, exp.GenerateTimestampArray]
 246) -> str:
 247    is_generate_date_array = isinstance(expression, exp.GenerateDateArray)
 248
 249    type = exp.DataType.Type.DATE if is_generate_date_array else exp.DataType.Type.TIMESTAMP
 250    start = _implicit_datetime_cast(expression.args.get("start"), type=type)
 251    end = _implicit_datetime_cast(expression.args.get("end"), type=type)
 252
 253    # BQ's GENERATE_DATE_ARRAY & GENERATE_TIMESTAMP_ARRAY are transformed to DuckDB'S GENERATE_SERIES
 254    gen_series: t.Union[exp.GenerateSeries, exp.Cast] = exp.GenerateSeries(
 255        start=start, end=end, step=expression.args.get("step")
 256    )
 257
 258    if is_generate_date_array:
 259        # The GENERATE_SERIES result type is TIMESTAMP array, so to match BQ's semantics for
 260        # GENERATE_DATE_ARRAY we must cast it back to DATE array
 261        gen_series = exp.cast(gen_series, exp.DataType.build("ARRAY<DATE>"))
 262
 263    return self.sql(gen_series)
 264
 265
 266def _json_extract_value_array_sql(
 267    self: DuckDB.Generator, expression: exp.JSONValueArray | exp.JSONExtractArray
 268) -> str:
 269    json_extract = exp.JSONExtract(this=expression.this, expression=expression.expression)
 270    data_type = "ARRAY<STRING>" if isinstance(expression, exp.JSONValueArray) else "ARRAY<JSON>"
 271    return self.sql(exp.cast(json_extract, to=exp.DataType.build(data_type)))
 272
 273
 274class DuckDB(Dialect):
 275    NULL_ORDERING = "nulls_are_last"
 276    SUPPORTS_USER_DEFINED_TYPES = False
 277    SAFE_DIVISION = True
 278    INDEX_OFFSET = 1
 279    CONCAT_COALESCE = True
 280    SUPPORTS_ORDER_BY_ALL = True
 281    SUPPORTS_FIXED_SIZE_ARRAYS = True
 282    STRICT_JSON_PATH_SYNTAX = False
 283
 284    # https://duckdb.org/docs/sql/introduction.html#creating-a-new-table
 285    NORMALIZATION_STRATEGY = NormalizationStrategy.CASE_INSENSITIVE
 286
 287    def to_json_path(self, path: t.Optional[exp.Expression]) -> t.Optional[exp.Expression]:
 288        if isinstance(path, exp.Literal):
 289            # DuckDB also supports the JSON pointer syntax, where every path starts with a `/`.
 290            # Additionally, it allows accessing the back of lists using the `[#-i]` syntax.
 291            # This check ensures we'll avoid trying to parse these as JSON paths, which can
 292            # either result in a noisy warning or in an invalid representation of the path.
 293            path_text = path.name
 294            if path_text.startswith("/") or "[#" in path_text:
 295                return path
 296
 297        return super().to_json_path(path)
 298
 299    class Tokenizer(tokens.Tokenizer):
 300        BYTE_STRINGS = [("e'", "'"), ("E'", "'")]
 301        HEREDOC_STRINGS = ["$"]
 302
 303        HEREDOC_TAG_IS_IDENTIFIER = True
 304        HEREDOC_STRING_ALTERNATIVE = TokenType.PARAMETER
 305
 306        KEYWORDS = {
 307            **tokens.Tokenizer.KEYWORDS,
 308            "//": TokenType.DIV,
 309            "**": TokenType.DSTAR,
 310            "^@": TokenType.CARET_AT,
 311            "@>": TokenType.AT_GT,
 312            "<@": TokenType.LT_AT,
 313            "ATTACH": TokenType.ATTACH,
 314            "BINARY": TokenType.VARBINARY,
 315            "BITSTRING": TokenType.BIT,
 316            "BPCHAR": TokenType.TEXT,
 317            "CHAR": TokenType.TEXT,
 318            "CHARACTER VARYING": TokenType.TEXT,
 319            "DETACH": TokenType.DETACH,
 320            "EXCLUDE": TokenType.EXCEPT,
 321            "LOGICAL": TokenType.BOOLEAN,
 322            "ONLY": TokenType.ONLY,
 323            "PIVOT_WIDER": TokenType.PIVOT,
 324            "POSITIONAL": TokenType.POSITIONAL,
 325            "SIGNED": TokenType.INT,
 326            "STRING": TokenType.TEXT,
 327            "SUMMARIZE": TokenType.SUMMARIZE,
 328            "TIMESTAMP_S": TokenType.TIMESTAMP_S,
 329            "TIMESTAMP_MS": TokenType.TIMESTAMP_MS,
 330            "TIMESTAMP_NS": TokenType.TIMESTAMP_NS,
 331            "TIMESTAMP_US": TokenType.TIMESTAMP,
 332            "UBIGINT": TokenType.UBIGINT,
 333            "UINTEGER": TokenType.UINT,
 334            "USMALLINT": TokenType.USMALLINT,
 335            "UTINYINT": TokenType.UTINYINT,
 336            "VARCHAR": TokenType.TEXT,
 337        }
 338        KEYWORDS.pop("/*+")
 339
 340        SINGLE_TOKENS = {
 341            **tokens.Tokenizer.SINGLE_TOKENS,
 342            "$": TokenType.PARAMETER,
 343        }
 344
 345    class Parser(parser.Parser):
 346        BITWISE = {
 347            **parser.Parser.BITWISE,
 348            TokenType.TILDA: exp.RegexpLike,
 349        }
 350        BITWISE.pop(TokenType.CARET)
 351
 352        RANGE_PARSERS = {
 353            **parser.Parser.RANGE_PARSERS,
 354            TokenType.DAMP: binary_range_parser(exp.ArrayOverlaps),
 355            TokenType.CARET_AT: binary_range_parser(exp.StartsWith),
 356        }
 357
 358        EXPONENT = {
 359            **parser.Parser.EXPONENT,
 360            TokenType.CARET: exp.Pow,
 361            TokenType.DSTAR: exp.Pow,
 362        }
 363
 364        FUNCTIONS_WITH_ALIASED_ARGS = {*parser.Parser.FUNCTIONS_WITH_ALIASED_ARGS, "STRUCT_PACK"}
 365
 366        FUNCTIONS = {
 367            **parser.Parser.FUNCTIONS,
 368            "ARRAY_REVERSE_SORT": _build_sort_array_desc,
 369            "ARRAY_SORT": exp.SortArray.from_arg_list,
 370            "DATEDIFF": _build_date_diff,
 371            "DATE_DIFF": _build_date_diff,
 372            "DATE_TRUNC": date_trunc_to_time,
 373            "DATETRUNC": date_trunc_to_time,
 374            "DECODE": lambda args: exp.Decode(
 375                this=seq_get(args, 0), charset=exp.Literal.string("utf-8")
 376            ),
 377            "ENCODE": lambda args: exp.Encode(
 378                this=seq_get(args, 0), charset=exp.Literal.string("utf-8")
 379            ),
 380            "EPOCH": exp.TimeToUnix.from_arg_list,
 381            "EPOCH_MS": lambda args: exp.UnixToTime(
 382                this=seq_get(args, 0), scale=exp.UnixToTime.MILLIS
 383            ),
 384            "JSON": exp.ParseJSON.from_arg_list,
 385            "JSON_EXTRACT_PATH": parser.build_extract_json_with_path(exp.JSONExtract),
 386            "JSON_EXTRACT_STRING": parser.build_extract_json_with_path(exp.JSONExtractScalar),
 387            "LIST_HAS": exp.ArrayContains.from_arg_list,
 388            "LIST_REVERSE_SORT": _build_sort_array_desc,
 389            "LIST_SORT": exp.SortArray.from_arg_list,
 390            "LIST_VALUE": lambda args: exp.Array(expressions=args),
 391            "MAKE_TIME": exp.TimeFromParts.from_arg_list,
 392            "MAKE_TIMESTAMP": _build_make_timestamp,
 393            "QUANTILE_CONT": exp.PercentileCont.from_arg_list,
 394            "QUANTILE_DISC": exp.PercentileDisc.from_arg_list,
 395            "REGEXP_EXTRACT": build_regexp_extract(exp.RegexpExtract),
 396            "REGEXP_EXTRACT_ALL": build_regexp_extract(exp.RegexpExtractAll),
 397            "REGEXP_MATCHES": exp.RegexpLike.from_arg_list,
 398            "REGEXP_REPLACE": lambda args: exp.RegexpReplace(
 399                this=seq_get(args, 0),
 400                expression=seq_get(args, 1),
 401                replacement=seq_get(args, 2),
 402                modifiers=seq_get(args, 3),
 403            ),
 404            "STRFTIME": build_formatted_time(exp.TimeToStr, "duckdb"),
 405            "STRING_SPLIT": exp.Split.from_arg_list,
 406            "STRING_SPLIT_REGEX": exp.RegexpSplit.from_arg_list,
 407            "STRING_TO_ARRAY": exp.Split.from_arg_list,
 408            "STRPTIME": build_formatted_time(exp.StrToTime, "duckdb"),
 409            "STRUCT_PACK": exp.Struct.from_arg_list,
 410            "STR_SPLIT": exp.Split.from_arg_list,
 411            "STR_SPLIT_REGEX": exp.RegexpSplit.from_arg_list,
 412            "TO_TIMESTAMP": exp.UnixToTime.from_arg_list,
 413            "UNNEST": exp.Explode.from_arg_list,
 414            "XOR": binary_from_function(exp.BitwiseXor),
 415            "GENERATE_SERIES": _build_generate_series(),
 416            "RANGE": _build_generate_series(end_exclusive=True),
 417            "EDITDIST3": exp.Levenshtein.from_arg_list,
 418        }
 419
 420        FUNCTIONS.pop("DATE_SUB")
 421        FUNCTIONS.pop("GLOB")
 422
 423        FUNCTION_PARSERS = parser.Parser.FUNCTION_PARSERS.copy()
 424        FUNCTION_PARSERS.pop("DECODE")
 425
 426        NO_PAREN_FUNCTION_PARSERS = {
 427            **parser.Parser.NO_PAREN_FUNCTION_PARSERS,
 428            "MAP": lambda self: self._parse_map(),
 429        }
 430
 431        TABLE_ALIAS_TOKENS = parser.Parser.TABLE_ALIAS_TOKENS - {
 432            TokenType.SEMI,
 433            TokenType.ANTI,
 434        }
 435
 436        PLACEHOLDER_PARSERS = {
 437            **parser.Parser.PLACEHOLDER_PARSERS,
 438            TokenType.PARAMETER: lambda self: (
 439                self.expression(exp.Placeholder, this=self._prev.text)
 440                if self._match(TokenType.NUMBER) or self._match_set(self.ID_VAR_TOKENS)
 441                else None
 442            ),
 443        }
 444
 445        TYPE_CONVERTERS = {
 446            # https://duckdb.org/docs/sql/data_types/numeric
 447            exp.DataType.Type.DECIMAL: build_default_decimal_type(precision=18, scale=3),
 448            # https://duckdb.org/docs/sql/data_types/text
 449            exp.DataType.Type.TEXT: lambda dtype: exp.DataType.build("TEXT"),
 450        }
 451
 452        STATEMENT_PARSERS = {
 453            **parser.Parser.STATEMENT_PARSERS,
 454            TokenType.ATTACH: lambda self: self._parse_attach_detach(),
 455            TokenType.DETACH: lambda self: self._parse_attach_detach(is_attach=False),
 456        }
 457
 458        def _parse_table_sample(self, as_modifier: bool = False) -> t.Optional[exp.TableSample]:
 459            # https://duckdb.org/docs/sql/samples.html
 460            sample = super()._parse_table_sample(as_modifier=as_modifier)
 461            if sample and not sample.args.get("method"):
 462                if sample.args.get("size"):
 463                    sample.set("method", exp.var("RESERVOIR"))
 464                else:
 465                    sample.set("method", exp.var("SYSTEM"))
 466
 467            return sample
 468
 469        def _parse_bracket(
 470            self, this: t.Optional[exp.Expression] = None
 471        ) -> t.Optional[exp.Expression]:
 472            bracket = super()._parse_bracket(this)
 473            if isinstance(bracket, exp.Bracket):
 474                bracket.set("returns_list_for_maps", True)
 475
 476            return bracket
 477
 478        def _parse_map(self) -> exp.ToMap | exp.Map:
 479            if self._match(TokenType.L_BRACE, advance=False):
 480                return self.expression(exp.ToMap, this=self._parse_bracket())
 481
 482            args = self._parse_wrapped_csv(self._parse_assignment)
 483            return self.expression(exp.Map, keys=seq_get(args, 0), values=seq_get(args, 1))
 484
 485        def _parse_struct_types(self, type_required: bool = False) -> t.Optional[exp.Expression]:
 486            return self._parse_field_def()
 487
 488        def _pivot_column_names(self, aggregations: t.List[exp.Expression]) -> t.List[str]:
 489            if len(aggregations) == 1:
 490                return super()._pivot_column_names(aggregations)
 491            return pivot_column_names(aggregations, dialect="duckdb")
 492
 493        def _parse_attach_detach(self, is_attach=True) -> exp.Attach | exp.Detach:
 494            def _parse_attach_option() -> exp.AttachOption:
 495                return self.expression(
 496                    exp.AttachOption,
 497                    this=self._parse_var(any_token=True),
 498                    expression=self._parse_field(any_token=True),
 499                )
 500
 501            self._match(TokenType.DATABASE)
 502            exists = self._parse_exists(not_=is_attach)
 503            this = self._parse_alias(self._parse_primary_or_var(), explicit=True)
 504
 505            if self._match(TokenType.L_PAREN, advance=False):
 506                expressions = self._parse_wrapped_csv(_parse_attach_option)
 507            else:
 508                expressions = None
 509
 510            return (
 511                self.expression(exp.Attach, this=this, exists=exists, expressions=expressions)
 512                if is_attach
 513                else self.expression(exp.Detach, this=this, exists=exists)
 514            )
 515
 516    class Generator(generator.Generator):
 517        PARAMETER_TOKEN = "$"
 518        NAMED_PLACEHOLDER_TOKEN = "$"
 519        JOIN_HINTS = False
 520        TABLE_HINTS = False
 521        QUERY_HINTS = False
 522        LIMIT_FETCH = "LIMIT"
 523        STRUCT_DELIMITER = ("(", ")")
 524        RENAME_TABLE_WITH_DB = False
 525        NVL2_SUPPORTED = False
 526        SEMI_ANTI_JOIN_WITH_SIDE = False
 527        TABLESAMPLE_KEYWORDS = "USING SAMPLE"
 528        TABLESAMPLE_SEED_KEYWORD = "REPEATABLE"
 529        LAST_DAY_SUPPORTS_DATE_PART = False
 530        JSON_KEY_VALUE_PAIR_SEP = ","
 531        IGNORE_NULLS_IN_FUNC = True
 532        JSON_PATH_BRACKETED_KEY_SUPPORTED = False
 533        SUPPORTS_CREATE_TABLE_LIKE = False
 534        MULTI_ARG_DISTINCT = False
 535        CAN_IMPLEMENT_ARRAY_ANY = True
 536        SUPPORTS_TO_NUMBER = False
 537        COPY_HAS_INTO_KEYWORD = False
 538        STAR_EXCEPT = "EXCLUDE"
 539        PAD_FILL_PATTERN_IS_REQUIRED = True
 540        ARRAY_CONCAT_IS_VAR_LEN = False
 541        ARRAY_SIZE_DIM_REQUIRED = False
 542
 543        TRANSFORMS = {
 544            **generator.Generator.TRANSFORMS,
 545            exp.ApproxDistinct: approx_count_distinct_sql,
 546            exp.Array: inline_array_unless_query,
 547            exp.ArrayFilter: rename_func("LIST_FILTER"),
 548            exp.ArraySort: _array_sort_sql,
 549            exp.ArraySum: rename_func("LIST_SUM"),
 550            exp.BitwiseXor: rename_func("XOR"),
 551            exp.CommentColumnConstraint: no_comment_column_constraint_sql,
 552            exp.CurrentDate: lambda *_: "CURRENT_DATE",
 553            exp.CurrentTime: lambda *_: "CURRENT_TIME",
 554            exp.CurrentTimestamp: lambda *_: "CURRENT_TIMESTAMP",
 555            exp.DayOfMonth: rename_func("DAYOFMONTH"),
 556            exp.DayOfWeek: rename_func("DAYOFWEEK"),
 557            exp.DayOfWeekIso: rename_func("ISODOW"),
 558            exp.DayOfYear: rename_func("DAYOFYEAR"),
 559            exp.DataType: _datatype_sql,
 560            exp.Date: _date_sql,
 561            exp.DateAdd: _date_delta_sql,
 562            exp.DateFromParts: rename_func("MAKE_DATE"),
 563            exp.DateSub: _date_delta_sql,
 564            exp.DateDiff: _date_diff_sql,
 565            exp.DateStrToDate: datestrtodate_sql,
 566            exp.Datetime: no_datetime_sql,
 567            exp.DatetimeSub: _date_delta_sql,
 568            exp.DatetimeAdd: _date_delta_sql,
 569            exp.DateToDi: lambda self,
 570            e: f"CAST(STRFTIME({self.sql(e, 'this')}, {DuckDB.DATEINT_FORMAT}) AS INT)",
 571            exp.Decode: lambda self, e: encode_decode_sql(self, e, "DECODE", replace=False),
 572            exp.DiToDate: lambda self,
 573            e: f"CAST(STRPTIME(CAST({self.sql(e, 'this')} AS TEXT), {DuckDB.DATEINT_FORMAT}) AS DATE)",
 574            exp.Encode: lambda self, e: encode_decode_sql(self, e, "ENCODE", replace=False),
 575            exp.GenerateDateArray: _generate_datetime_array_sql,
 576            exp.GenerateTimestampArray: _generate_datetime_array_sql,
 577            exp.Explode: rename_func("UNNEST"),
 578            exp.IntDiv: lambda self, e: self.binary(e, "//"),
 579            exp.IsInf: rename_func("ISINF"),
 580            exp.IsNan: rename_func("ISNAN"),
 581            exp.JSONBExists: rename_func("JSON_EXISTS"),
 582            exp.JSONExtract: _arrow_json_extract_sql,
 583            exp.JSONExtractArray: _json_extract_value_array_sql,
 584            exp.JSONExtractScalar: _arrow_json_extract_sql,
 585            exp.JSONFormat: _json_format_sql,
 586            exp.JSONValueArray: _json_extract_value_array_sql,
 587            exp.Lateral: explode_to_unnest_sql,
 588            exp.LogicalOr: rename_func("BOOL_OR"),
 589            exp.LogicalAnd: rename_func("BOOL_AND"),
 590            exp.MakeInterval: lambda self, e: no_make_interval_sql(self, e, sep=" "),
 591            exp.MD5Digest: lambda self, e: self.func("UNHEX", self.func("MD5", e.this)),
 592            exp.MonthsBetween: lambda self, e: self.func(
 593                "DATEDIFF",
 594                "'month'",
 595                exp.cast(e.expression, exp.DataType.Type.TIMESTAMP, copy=True),
 596                exp.cast(e.this, exp.DataType.Type.TIMESTAMP, copy=True),
 597            ),
 598            exp.PercentileCont: rename_func("QUANTILE_CONT"),
 599            exp.PercentileDisc: rename_func("QUANTILE_DISC"),
 600            # DuckDB doesn't allow qualified columns inside of PIVOT expressions.
 601            # See: https://github.com/duckdb/duckdb/blob/671faf92411182f81dce42ac43de8bfb05d9909e/src/planner/binder/tableref/bind_pivot.cpp#L61-L62
 602            exp.Pivot: transforms.preprocess([transforms.unqualify_columns]),
 603            exp.RegexpReplace: lambda self, e: self.func(
 604                "REGEXP_REPLACE",
 605                e.this,
 606                e.expression,
 607                e.args.get("replacement"),
 608                e.args.get("modifiers"),
 609            ),
 610            exp.RegexpLike: rename_func("REGEXP_MATCHES"),
 611            exp.RegexpSplit: rename_func("STR_SPLIT_REGEX"),
 612            exp.Return: lambda self, e: self.sql(e, "this"),
 613            exp.ReturnsProperty: lambda self, e: "TABLE" if isinstance(e.this, exp.Schema) else "",
 614            exp.Rand: rename_func("RANDOM"),
 615            exp.SafeDivide: no_safe_divide_sql,
 616            exp.SHA: rename_func("SHA1"),
 617            exp.SHA2: sha256_sql,
 618            exp.Split: rename_func("STR_SPLIT"),
 619            exp.SortArray: _sort_array_sql,
 620            exp.StrPosition: str_position_sql,
 621            exp.StrToUnix: lambda self, e: self.func(
 622                "EPOCH", self.func("STRPTIME", e.this, self.format_time(e))
 623            ),
 624            exp.Struct: _struct_sql,
 625            exp.Transform: rename_func("LIST_TRANSFORM"),
 626            exp.TimeAdd: _date_delta_sql,
 627            exp.Time: no_time_sql,
 628            exp.TimeDiff: _timediff_sql,
 629            exp.Timestamp: no_timestamp_sql,
 630            exp.TimestampDiff: lambda self, e: self.func(
 631                "DATE_DIFF", exp.Literal.string(e.unit), e.expression, e.this
 632            ),
 633            exp.TimestampTrunc: timestamptrunc_sql(),
 634            exp.TimeStrToDate: lambda self, e: self.sql(exp.cast(e.this, exp.DataType.Type.DATE)),
 635            exp.TimeStrToTime: timestrtotime_sql,
 636            exp.TimeStrToUnix: lambda self, e: self.func(
 637                "EPOCH", exp.cast(e.this, exp.DataType.Type.TIMESTAMP)
 638            ),
 639            exp.TimeToStr: lambda self, e: self.func("STRFTIME", e.this, self.format_time(e)),
 640            exp.TimeToUnix: rename_func("EPOCH"),
 641            exp.TsOrDiToDi: lambda self,
 642            e: f"CAST(SUBSTR(REPLACE(CAST({self.sql(e, 'this')} AS TEXT), '-', ''), 1, 8) AS INT)",
 643            exp.TsOrDsAdd: _date_delta_sql,
 644            exp.TsOrDsDiff: lambda self, e: self.func(
 645                "DATE_DIFF",
 646                f"'{e.args.get('unit') or 'DAY'}'",
 647                exp.cast(e.expression, exp.DataType.Type.TIMESTAMP),
 648                exp.cast(e.this, exp.DataType.Type.TIMESTAMP),
 649            ),
 650            exp.UnixToStr: lambda self, e: self.func(
 651                "STRFTIME", self.func("TO_TIMESTAMP", e.this), self.format_time(e)
 652            ),
 653            exp.DatetimeTrunc: lambda self, e: self.func(
 654                "DATE_TRUNC", unit_to_str(e), exp.cast(e.this, exp.DataType.Type.DATETIME)
 655            ),
 656            exp.UnixToTime: _unix_to_time_sql,
 657            exp.UnixToTimeStr: lambda self, e: f"CAST(TO_TIMESTAMP({self.sql(e, 'this')}) AS TEXT)",
 658            exp.VariancePop: rename_func("VAR_POP"),
 659            exp.WeekOfYear: rename_func("WEEKOFYEAR"),
 660            exp.Xor: bool_xor_sql,
 661            exp.Levenshtein: unsupported_args("ins_cost", "del_cost", "sub_cost", "max_dist")(
 662                rename_func("LEVENSHTEIN")
 663            ),
 664        }
 665
 666        SUPPORTED_JSON_PATH_PARTS = {
 667            exp.JSONPathKey,
 668            exp.JSONPathRoot,
 669            exp.JSONPathSubscript,
 670            exp.JSONPathWildcard,
 671        }
 672
 673        TYPE_MAPPING = {
 674            **generator.Generator.TYPE_MAPPING,
 675            exp.DataType.Type.BINARY: "BLOB",
 676            exp.DataType.Type.BPCHAR: "TEXT",
 677            exp.DataType.Type.CHAR: "TEXT",
 678            exp.DataType.Type.DATETIME: "TIMESTAMP",
 679            exp.DataType.Type.FLOAT: "REAL",
 680            exp.DataType.Type.NCHAR: "TEXT",
 681            exp.DataType.Type.NVARCHAR: "TEXT",
 682            exp.DataType.Type.UINT: "UINTEGER",
 683            exp.DataType.Type.VARBINARY: "BLOB",
 684            exp.DataType.Type.ROWVERSION: "BLOB",
 685            exp.DataType.Type.VARCHAR: "TEXT",
 686            exp.DataType.Type.TIMESTAMPNTZ: "TIMESTAMP",
 687            exp.DataType.Type.TIMESTAMP_S: "TIMESTAMP_S",
 688            exp.DataType.Type.TIMESTAMP_MS: "TIMESTAMP_MS",
 689            exp.DataType.Type.TIMESTAMP_NS: "TIMESTAMP_NS",
 690        }
 691
 692        # https://github.com/duckdb/duckdb/blob/ff7f24fd8e3128d94371827523dae85ebaf58713/third_party/libpg_query/grammar/keywords/reserved_keywords.list#L1-L77
 693        RESERVED_KEYWORDS = {
 694            "array",
 695            "analyse",
 696            "union",
 697            "all",
 698            "when",
 699            "in_p",
 700            "default",
 701            "create_p",
 702            "window",
 703            "asymmetric",
 704            "to",
 705            "else",
 706            "localtime",
 707            "from",
 708            "end_p",
 709            "select",
 710            "current_date",
 711            "foreign",
 712            "with",
 713            "grant",
 714            "session_user",
 715            "or",
 716            "except",
 717            "references",
 718            "fetch",
 719            "limit",
 720            "group_p",
 721            "leading",
 722            "into",
 723            "collate",
 724            "offset",
 725            "do",
 726            "then",
 727            "localtimestamp",
 728            "check_p",
 729            "lateral_p",
 730            "current_role",
 731            "where",
 732            "asc_p",
 733            "placing",
 734            "desc_p",
 735            "user",
 736            "unique",
 737            "initially",
 738            "column",
 739            "both",
 740            "some",
 741            "as",
 742            "any",
 743            "only",
 744            "deferrable",
 745            "null_p",
 746            "current_time",
 747            "true_p",
 748            "table",
 749            "case",
 750            "trailing",
 751            "variadic",
 752            "for",
 753            "on",
 754            "distinct",
 755            "false_p",
 756            "not",
 757            "constraint",
 758            "current_timestamp",
 759            "returning",
 760            "primary",
 761            "intersect",
 762            "having",
 763            "analyze",
 764            "current_user",
 765            "and",
 766            "cast",
 767            "symmetric",
 768            "using",
 769            "order",
 770            "current_catalog",
 771        }
 772
 773        UNWRAPPED_INTERVAL_VALUES = (exp.Literal, exp.Paren)
 774
 775        # DuckDB doesn't generally support CREATE TABLE .. properties
 776        # https://duckdb.org/docs/sql/statements/create_table.html
 777        PROPERTIES_LOCATION = {
 778            prop: exp.Properties.Location.UNSUPPORTED
 779            for prop in generator.Generator.PROPERTIES_LOCATION
 780        }
 781
 782        # There are a few exceptions (e.g. temporary tables) which are supported or
 783        # can be transpiled to DuckDB, so we explicitly override them accordingly
 784        PROPERTIES_LOCATION[exp.LikeProperty] = exp.Properties.Location.POST_SCHEMA
 785        PROPERTIES_LOCATION[exp.TemporaryProperty] = exp.Properties.Location.POST_CREATE
 786        PROPERTIES_LOCATION[exp.ReturnsProperty] = exp.Properties.Location.POST_ALIAS
 787
 788        def fromiso8601timestamp_sql(self, expression: exp.FromISO8601Timestamp) -> str:
 789            return self.sql(exp.cast(expression.this, exp.DataType.Type.TIMESTAMPTZ))
 790
 791        def strtotime_sql(self, expression: exp.StrToTime) -> str:
 792            if expression.args.get("safe"):
 793                formatted_time = self.format_time(expression)
 794                return f"CAST({self.func('TRY_STRPTIME', expression.this, formatted_time)} AS TIMESTAMP)"
 795            return str_to_time_sql(self, expression)
 796
 797        def strtodate_sql(self, expression: exp.StrToDate) -> str:
 798            if expression.args.get("safe"):
 799                formatted_time = self.format_time(expression)
 800                return f"CAST({self.func('TRY_STRPTIME', expression.this, formatted_time)} AS DATE)"
 801            return f"CAST({str_to_time_sql(self, expression)} AS DATE)"
 802
 803        def parsejson_sql(self, expression: exp.ParseJSON) -> str:
 804            arg = expression.this
 805            if expression.args.get("safe"):
 806                return self.sql(exp.case().when(exp.func("json_valid", arg), arg).else_(exp.null()))
 807            return self.func("JSON", arg)
 808
 809        def timefromparts_sql(self, expression: exp.TimeFromParts) -> str:
 810            nano = expression.args.get("nano")
 811            if nano is not None:
 812                expression.set(
 813                    "sec", expression.args["sec"] + nano.pop() / exp.Literal.number(1000000000.0)
 814                )
 815
 816            return rename_func("MAKE_TIME")(self, expression)
 817
 818        def timestampfromparts_sql(self, expression: exp.TimestampFromParts) -> str:
 819            sec = expression.args["sec"]
 820
 821            milli = expression.args.get("milli")
 822            if milli is not None:
 823                sec += milli.pop() / exp.Literal.number(1000.0)
 824
 825            nano = expression.args.get("nano")
 826            if nano is not None:
 827                sec += nano.pop() / exp.Literal.number(1000000000.0)
 828
 829            if milli or nano:
 830                expression.set("sec", sec)
 831
 832            return rename_func("MAKE_TIMESTAMP")(self, expression)
 833
 834        def tablesample_sql(
 835            self,
 836            expression: exp.TableSample,
 837            tablesample_keyword: t.Optional[str] = None,
 838        ) -> str:
 839            if not isinstance(expression.parent, exp.Select):
 840                # This sample clause only applies to a single source, not the entire resulting relation
 841                tablesample_keyword = "TABLESAMPLE"
 842
 843            if expression.args.get("size"):
 844                method = expression.args.get("method")
 845                if method and method.name.upper() != "RESERVOIR":
 846                    self.unsupported(
 847                        f"Sampling method {method} is not supported with a discrete sample count, "
 848                        "defaulting to reservoir sampling"
 849                    )
 850                    expression.set("method", exp.var("RESERVOIR"))
 851
 852            return super().tablesample_sql(expression, tablesample_keyword=tablesample_keyword)
 853
 854        def interval_sql(self, expression: exp.Interval) -> str:
 855            multiplier: t.Optional[int] = None
 856            unit = expression.text("unit").lower()
 857
 858            if unit.startswith("week"):
 859                multiplier = 7
 860            if unit.startswith("quarter"):
 861                multiplier = 90
 862
 863            if multiplier:
 864                return f"({multiplier} * {super().interval_sql(exp.Interval(this=expression.this, unit=exp.var('DAY')))})"
 865
 866            return super().interval_sql(expression)
 867
 868        def columndef_sql(self, expression: exp.ColumnDef, sep: str = " ") -> str:
 869            if isinstance(expression.parent, exp.UserDefinedFunction):
 870                return self.sql(expression, "this")
 871            return super().columndef_sql(expression, sep)
 872
 873        def join_sql(self, expression: exp.Join) -> str:
 874            if (
 875                expression.side == "LEFT"
 876                and not expression.args.get("on")
 877                and isinstance(expression.this, exp.Unnest)
 878            ):
 879                # Some dialects support `LEFT JOIN UNNEST(...)` without an explicit ON clause
 880                # DuckDB doesn't, but we can just add a dummy ON clause that is always true
 881                return super().join_sql(expression.on(exp.true()))
 882
 883            return super().join_sql(expression)
 884
 885        def generateseries_sql(self, expression: exp.GenerateSeries) -> str:
 886            # GENERATE_SERIES(a, b) -> [a, b], RANGE(a, b) -> [a, b)
 887            if expression.args.get("is_end_exclusive"):
 888                return rename_func("RANGE")(self, expression)
 889
 890            return self.function_fallback_sql(expression)
 891
 892        def bracket_sql(self, expression: exp.Bracket) -> str:
 893            this = expression.this
 894            if isinstance(this, exp.Array):
 895                this.replace(exp.paren(this))
 896
 897            bracket = super().bracket_sql(expression)
 898
 899            if not expression.args.get("returns_list_for_maps"):
 900                if not this.type:
 901                    from sqlglot.optimizer.annotate_types import annotate_types
 902
 903                    this = annotate_types(this)
 904
 905                if this.is_type(exp.DataType.Type.MAP):
 906                    bracket = f"({bracket})[1]"
 907
 908            return bracket
 909
 910        def withingroup_sql(self, expression: exp.WithinGroup) -> str:
 911            expression_sql = self.sql(expression, "expression")
 912
 913            func = expression.this
 914            if isinstance(func, exp.PERCENTILES):
 915                # Make the order key the first arg and slide the fraction to the right
 916                # https://duckdb.org/docs/sql/aggregates#ordered-set-aggregate-functions
 917                order_col = expression.find(exp.Ordered)
 918                if order_col:
 919                    func.set("expression", func.this)
 920                    func.set("this", order_col.this)
 921
 922            this = self.sql(expression, "this").rstrip(")")
 923
 924            return f"{this}{expression_sql})"
 925
 926        def length_sql(self, expression: exp.Length) -> str:
 927            arg = expression.this
 928
 929            # Dialects like BQ and Snowflake also accept binary values as args, so
 930            # DDB will attempt to infer the type or resort to case/when resolution
 931            if not expression.args.get("binary") or arg.is_string:
 932                return self.func("LENGTH", arg)
 933
 934            if not arg.type:
 935                from sqlglot.optimizer.annotate_types import annotate_types
 936
 937                arg = annotate_types(arg)
 938
 939            if arg.is_type(*exp.DataType.TEXT_TYPES):
 940                return self.func("LENGTH", arg)
 941
 942            # We need these casts to make duckdb's static type checker happy
 943            blob = exp.cast(arg, exp.DataType.Type.VARBINARY)
 944            varchar = exp.cast(arg, exp.DataType.Type.VARCHAR)
 945
 946            case = (
 947                exp.case(self.func("TYPEOF", arg))
 948                .when(
 949                    "'VARCHAR'", exp.Anonymous(this="LENGTH", expressions=[varchar])
 950                )  # anonymous to break length_sql recursion
 951                .when("'BLOB'", self.func("OCTET_LENGTH", blob))
 952            )
 953
 954            return self.sql(case)
 955
 956        def objectinsert_sql(self, expression: exp.ObjectInsert) -> str:
 957            this = expression.this
 958            key = expression.args.get("key")
 959            key_sql = key.name if isinstance(key, exp.Expression) else ""
 960            value_sql = self.sql(expression, "value")
 961
 962            kv_sql = f"{key_sql} := {value_sql}"
 963
 964            # If the input struct is empty e.g. transpiling OBJECT_INSERT(OBJECT_CONSTRUCT(), key, value) from Snowflake
 965            # then we can generate STRUCT_PACK which will build it since STRUCT_INSERT({}, key := value) is not valid DuckDB
 966            if isinstance(this, exp.Struct) and not this.expressions:
 967                return self.func("STRUCT_PACK", kv_sql)
 968
 969            return self.func("STRUCT_INSERT", this, kv_sql)
 970
 971        def unnest_sql(self, expression: exp.Unnest) -> str:
 972            explode_array = expression.args.get("explode_array")
 973            if explode_array:
 974                # In BigQuery, UNNESTing a nested array leads to explosion of the top-level array & struct
 975                # This is transpiled to DDB by transforming "FROM UNNEST(...)" to "FROM (SELECT UNNEST(..., max_depth => 2))"
 976                expression.expressions.append(
 977                    exp.Kwarg(this=exp.var("max_depth"), expression=exp.Literal.number(2))
 978                )
 979
 980                # If BQ's UNNEST is aliased, we transform it from a column alias to a table alias in DDB
 981                alias = expression.args.get("alias")
 982                if alias:
 983                    expression.set("alias", None)
 984                    alias = exp.TableAlias(this=seq_get(alias.args.get("columns"), 0))
 985
 986                unnest_sql = super().unnest_sql(expression)
 987                select = exp.Select(expressions=[unnest_sql]).subquery(alias)
 988                return self.sql(select)
 989
 990            return super().unnest_sql(expression)
 991
 992        def ignorenulls_sql(self, expression: exp.IgnoreNulls) -> str:
 993            if isinstance(expression.this, WINDOW_FUNCS_WITH_IGNORE_NULLS):
 994                # DuckDB should render IGNORE NULLS only for the general-purpose
 995                # window functions that accept it e.g. FIRST_VALUE(... IGNORE NULLS) OVER (...)
 996                return super().ignorenulls_sql(expression)
 997
 998            return self.sql(expression, "this")
 999
1000        def arraytostring_sql(self, expression: exp.ArrayToString) -> str:
1001            this = self.sql(expression, "this")
1002            null_text = self.sql(expression, "null")
1003
1004            if null_text:
1005                this = f"LIST_TRANSFORM({this}, x -> COALESCE(x, {null_text}))"
1006
1007            return self.func("ARRAY_TO_STRING", this, expression.expression)
1008
1009        @unsupported_args("position", "occurrence")
1010        def regexpextract_sql(self, expression: exp.RegexpExtract) -> str:
1011            group = expression.args.get("group")
1012            params = expression.args.get("parameters")
1013
1014            # Do not render group if there is no following argument,
1015            # and it's the default value for this dialect
1016            if (
1017                not params
1018                and group
1019                and group.name == str(self.dialect.REGEXP_EXTRACT_DEFAULT_GROUP)
1020            ):
1021                group = None
1022            return self.func(
1023                "REGEXP_EXTRACT", expression.this, expression.expression, group, params
1024            )
1025
1026        @unsupported_args("culture")
1027        def numbertostr_sql(self, expression: exp.NumberToStr) -> str:
1028            fmt = expression.args.get("format")
1029            if fmt and fmt.is_int:
1030                return self.func("FORMAT", f"'{{:,.{fmt.name}f}}'", expression.this)
1031
1032            self.unsupported("Only integer formats are supported by NumberToStr")
1033            return self.function_fallback_sql(expression)