sqlglot.dialects.bigquery

   1from __future__ import annotations
   2
   3import logging
   4import re
   5import typing as t
   6
   7from sqlglot import exp, generator, parser, tokens, transforms
   8from sqlglot._typing import E
   9from sqlglot.dialects.dialect import (
  10    Dialect,
  11    NormalizationStrategy,
  12    annotate_with_type_lambda,
  13    arg_max_or_min_no_count,
  14    binary_from_function,
  15    date_add_interval_sql,
  16    datestrtodate_sql,
  17    build_formatted_time,
  18    filter_array_using_unnest,
  19    if_sql,
  20    inline_array_unless_query,
  21    max_or_greatest,
  22    min_or_least,
  23    no_ilike_sql,
  24    build_date_delta_with_interval,
  25    regexp_replace_sql,
  26    rename_func,
  27    sha256_sql,
  28    timestrtotime_sql,
  29    ts_or_ds_add_cast,
  30    unit_to_var,
  31    strposition_sql,
  32    groupconcat_sql,
  33    space_sql,
  34)
  35from sqlglot.helper import seq_get, split_num_words
  36from sqlglot.tokens import TokenType
  37from sqlglot.generator import unsupported_args
  38
  39if t.TYPE_CHECKING:
  40    from sqlglot._typing import Lit
  41
  42    from sqlglot.optimizer.annotate_types import TypeAnnotator
  43
  44logger = logging.getLogger("sqlglot")
  45
  46
  47JSON_EXTRACT_TYPE = t.Union[exp.JSONExtract, exp.JSONExtractScalar, exp.JSONExtractArray]
  48
  49DQUOTES_ESCAPING_JSON_FUNCTIONS = ("JSON_QUERY", "JSON_VALUE", "JSON_QUERY_ARRAY")
  50
  51
  52def _derived_table_values_to_unnest(self: BigQuery.Generator, expression: exp.Values) -> str:
  53    if not expression.find_ancestor(exp.From, exp.Join):
  54        return self.values_sql(expression)
  55
  56    structs = []
  57    alias = expression.args.get("alias")
  58    for tup in expression.find_all(exp.Tuple):
  59        field_aliases = (
  60            alias.columns
  61            if alias and alias.columns
  62            else (f"_c{i}" for i in range(len(tup.expressions)))
  63        )
  64        expressions = [
  65            exp.PropertyEQ(this=exp.to_identifier(name), expression=fld)
  66            for name, fld in zip(field_aliases, tup.expressions)
  67        ]
  68        structs.append(exp.Struct(expressions=expressions))
  69
  70    # Due to `UNNEST_COLUMN_ONLY`, it is expected that the table alias be contained in the columns expression
  71    alias_name_only = exp.TableAlias(columns=[alias.this]) if alias else None
  72    return self.unnest_sql(
  73        exp.Unnest(expressions=[exp.array(*structs, copy=False)], alias=alias_name_only)
  74    )
  75
  76
  77def _returnsproperty_sql(self: BigQuery.Generator, expression: exp.ReturnsProperty) -> str:
  78    this = expression.this
  79    if isinstance(this, exp.Schema):
  80        this = f"{self.sql(this, 'this')} <{self.expressions(this)}>"
  81    else:
  82        this = self.sql(this)
  83    return f"RETURNS {this}"
  84
  85
  86def _create_sql(self: BigQuery.Generator, expression: exp.Create) -> str:
  87    returns = expression.find(exp.ReturnsProperty)
  88    if expression.kind == "FUNCTION" and returns and returns.args.get("is_table"):
  89        expression.set("kind", "TABLE FUNCTION")
  90
  91        if isinstance(expression.expression, (exp.Subquery, exp.Literal)):
  92            expression.set("expression", expression.expression.this)
  93
  94    return self.create_sql(expression)
  95
  96
  97# https://issuetracker.google.com/issues/162294746
  98# workaround for bigquery bug when grouping by an expression and then ordering
  99# WITH x AS (SELECT 1 y)
 100# SELECT y + 1 z
 101# FROM x
 102# GROUP BY x + 1
 103# ORDER by z
 104def _alias_ordered_group(expression: exp.Expression) -> exp.Expression:
 105    if isinstance(expression, exp.Select):
 106        group = expression.args.get("group")
 107        order = expression.args.get("order")
 108
 109        if group and order:
 110            aliases = {
 111                select.this: select.args["alias"]
 112                for select in expression.selects
 113                if isinstance(select, exp.Alias)
 114            }
 115
 116            for grouped in group.expressions:
 117                if grouped.is_int:
 118                    continue
 119                alias = aliases.get(grouped)
 120                if alias:
 121                    grouped.replace(exp.column(alias))
 122
 123    return expression
 124
 125
 126def _pushdown_cte_column_names(expression: exp.Expression) -> exp.Expression:
 127    """BigQuery doesn't allow column names when defining a CTE, so we try to push them down."""
 128    if isinstance(expression, exp.CTE) and expression.alias_column_names:
 129        cte_query = expression.this
 130
 131        if cte_query.is_star:
 132            logger.warning(
 133                "Can't push down CTE column names for star queries. Run the query through"
 134                " the optimizer or use 'qualify' to expand the star projections first."
 135            )
 136            return expression
 137
 138        column_names = expression.alias_column_names
 139        expression.args["alias"].set("columns", None)
 140
 141        for name, select in zip(column_names, cte_query.selects):
 142            to_replace = select
 143
 144            if isinstance(select, exp.Alias):
 145                select = select.this
 146
 147            # Inner aliases are shadowed by the CTE column names
 148            to_replace.replace(exp.alias_(select, name))
 149
 150    return expression
 151
 152
 153def _build_parse_timestamp(args: t.List) -> exp.StrToTime:
 154    this = build_formatted_time(exp.StrToTime, "bigquery")([seq_get(args, 1), seq_get(args, 0)])
 155    this.set("zone", seq_get(args, 2))
 156    return this
 157
 158
 159def _build_timestamp(args: t.List) -> exp.Timestamp:
 160    timestamp = exp.Timestamp.from_arg_list(args)
 161    timestamp.set("with_tz", True)
 162    return timestamp
 163
 164
 165def _build_date(args: t.List) -> exp.Date | exp.DateFromParts:
 166    expr_type = exp.DateFromParts if len(args) == 3 else exp.Date
 167    return expr_type.from_arg_list(args)
 168
 169
 170def _build_to_hex(args: t.List) -> exp.Hex | exp.MD5:
 171    # TO_HEX(MD5(..)) is common in BigQuery, so it's parsed into MD5 to simplify its transpilation
 172    arg = seq_get(args, 0)
 173    return exp.MD5(this=arg.this) if isinstance(arg, exp.MD5Digest) else exp.LowerHex(this=arg)
 174
 175
 176def _array_contains_sql(self: BigQuery.Generator, expression: exp.ArrayContains) -> str:
 177    return self.sql(
 178        exp.Exists(
 179            this=exp.select("1")
 180            .from_(exp.Unnest(expressions=[expression.left]).as_("_unnest", table=["_col"]))
 181            .where(exp.column("_col").eq(expression.right))
 182        )
 183    )
 184
 185
 186def _ts_or_ds_add_sql(self: BigQuery.Generator, expression: exp.TsOrDsAdd) -> str:
 187    return date_add_interval_sql("DATE", "ADD")(self, ts_or_ds_add_cast(expression))
 188
 189
 190def _ts_or_ds_diff_sql(self: BigQuery.Generator, expression: exp.TsOrDsDiff) -> str:
 191    expression.this.replace(exp.cast(expression.this, exp.DataType.Type.TIMESTAMP))
 192    expression.expression.replace(exp.cast(expression.expression, exp.DataType.Type.TIMESTAMP))
 193    unit = unit_to_var(expression)
 194    return self.func("DATE_DIFF", expression.this, expression.expression, unit)
 195
 196
 197def _unix_to_time_sql(self: BigQuery.Generator, expression: exp.UnixToTime) -> str:
 198    scale = expression.args.get("scale")
 199    timestamp = expression.this
 200
 201    if scale in (None, exp.UnixToTime.SECONDS):
 202        return self.func("TIMESTAMP_SECONDS", timestamp)
 203    if scale == exp.UnixToTime.MILLIS:
 204        return self.func("TIMESTAMP_MILLIS", timestamp)
 205    if scale == exp.UnixToTime.MICROS:
 206        return self.func("TIMESTAMP_MICROS", timestamp)
 207
 208    unix_seconds = exp.cast(
 209        exp.Div(this=timestamp, expression=exp.func("POW", 10, scale)), exp.DataType.Type.BIGINT
 210    )
 211    return self.func("TIMESTAMP_SECONDS", unix_seconds)
 212
 213
 214def _build_time(args: t.List) -> exp.Func:
 215    if len(args) == 1:
 216        return exp.TsOrDsToTime(this=args[0])
 217    if len(args) == 2:
 218        return exp.Time.from_arg_list(args)
 219    return exp.TimeFromParts.from_arg_list(args)
 220
 221
 222def _build_datetime(args: t.List) -> exp.Func:
 223    if len(args) == 1:
 224        return exp.TsOrDsToDatetime.from_arg_list(args)
 225    if len(args) == 2:
 226        return exp.Datetime.from_arg_list(args)
 227    return exp.TimestampFromParts.from_arg_list(args)
 228
 229
 230def _build_regexp_extract(
 231    expr_type: t.Type[E], default_group: t.Optional[exp.Expression] = None
 232) -> t.Callable[[t.List], E]:
 233    def _builder(args: t.List) -> E:
 234        try:
 235            group = re.compile(args[1].name).groups == 1
 236        except re.error:
 237            group = False
 238
 239        # Default group is used for the transpilation of REGEXP_EXTRACT_ALL
 240        return expr_type(
 241            this=seq_get(args, 0),
 242            expression=seq_get(args, 1),
 243            position=seq_get(args, 2),
 244            occurrence=seq_get(args, 3),
 245            group=exp.Literal.number(1) if group else default_group,
 246        )
 247
 248    return _builder
 249
 250
 251def _build_extract_json_with_default_path(expr_type: t.Type[E]) -> t.Callable[[t.List, Dialect], E]:
 252    def _builder(args: t.List, dialect: Dialect) -> E:
 253        if len(args) == 1:
 254            # The default value for the JSONPath is '$' i.e all of the data
 255            args.append(exp.Literal.string("$"))
 256        return parser.build_extract_json_with_path(expr_type)(args, dialect)
 257
 258    return _builder
 259
 260
 261def _str_to_datetime_sql(
 262    self: BigQuery.Generator, expression: exp.StrToDate | exp.StrToTime
 263) -> str:
 264    this = self.sql(expression, "this")
 265    dtype = "DATE" if isinstance(expression, exp.StrToDate) else "TIMESTAMP"
 266
 267    if expression.args.get("safe"):
 268        fmt = self.format_time(
 269            expression,
 270            self.dialect.INVERSE_FORMAT_MAPPING,
 271            self.dialect.INVERSE_FORMAT_TRIE,
 272        )
 273        return f"SAFE_CAST({this} AS {dtype} FORMAT {fmt})"
 274
 275    fmt = self.format_time(expression)
 276    return self.func(f"PARSE_{dtype}", fmt, this, expression.args.get("zone"))
 277
 278
 279def _annotate_math_functions(self: TypeAnnotator, expression: E) -> E:
 280    """
 281    Many BigQuery math functions such as CEIL, FLOOR etc follow this return type convention:
 282    +---------+---------+---------+------------+---------+
 283    |  INPUT  | INT64   | NUMERIC | BIGNUMERIC | FLOAT64 |
 284    +---------+---------+---------+------------+---------+
 285    |  OUTPUT | FLOAT64 | NUMERIC | BIGNUMERIC | FLOAT64 |
 286    +---------+---------+---------+------------+---------+
 287    """
 288    self._annotate_args(expression)
 289
 290    this: exp.Expression = expression.this
 291
 292    self._set_type(
 293        expression,
 294        exp.DataType.Type.DOUBLE if this.is_type(*exp.DataType.INTEGER_TYPES) else this.type,
 295    )
 296    return expression
 297
 298
 299@unsupported_args("ins_cost", "del_cost", "sub_cost")
 300def _levenshtein_sql(self: BigQuery.Generator, expression: exp.Levenshtein) -> str:
 301    max_dist = expression.args.get("max_dist")
 302    if max_dist:
 303        max_dist = exp.Kwarg(this=exp.var("max_distance"), expression=max_dist)
 304
 305    return self.func("EDIT_DISTANCE", expression.this, expression.expression, max_dist)
 306
 307
 308def _build_levenshtein(args: t.List) -> exp.Levenshtein:
 309    max_dist = seq_get(args, 2)
 310    return exp.Levenshtein(
 311        this=seq_get(args, 0),
 312        expression=seq_get(args, 1),
 313        max_dist=max_dist.expression if max_dist else None,
 314    )
 315
 316
 317def _build_format_time(expr_type: t.Type[exp.Expression]) -> t.Callable[[t.List], exp.TimeToStr]:
 318    def _builder(args: t.List) -> exp.TimeToStr:
 319        return exp.TimeToStr(
 320            this=expr_type(this=seq_get(args, 1)),
 321            format=seq_get(args, 0),
 322            zone=seq_get(args, 2),
 323        )
 324
 325    return _builder
 326
 327
 328def _build_contains_substring(args: t.List) -> exp.Contains | exp.Anonymous:
 329    if len(args) == 3:
 330        return exp.Anonymous(this="CONTAINS_SUBSTR", expressions=args)
 331
 332    # Lowercase the operands in case of transpilation, as exp.Contains
 333    # is case-sensitive on other dialects
 334    this = exp.Lower(this=seq_get(args, 0))
 335    expr = exp.Lower(this=seq_get(args, 1))
 336
 337    return exp.Contains(this=this, expression=expr)
 338
 339
 340def _json_extract_sql(self: BigQuery.Generator, expression: JSON_EXTRACT_TYPE) -> str:
 341    name = (expression._meta and expression.meta.get("name")) or expression.sql_name()
 342    upper = name.upper()
 343
 344    dquote_escaping = upper in DQUOTES_ESCAPING_JSON_FUNCTIONS
 345
 346    if dquote_escaping:
 347        self._quote_json_path_key_using_brackets = False
 348
 349    sql = rename_func(upper)(self, expression)
 350
 351    if dquote_escaping:
 352        self._quote_json_path_key_using_brackets = True
 353
 354    return sql
 355
 356
 357def _annotate_concat(self: TypeAnnotator, expression: exp.Concat) -> exp.Concat:
 358    annotated = self._annotate_by_args(expression, "expressions")
 359
 360    # Args must be BYTES or types that can be cast to STRING, return type is either BYTES or STRING
 361    # https://cloud.google.com/bigquery/docs/reference/standard-sql/string_functions#concat
 362    if not annotated.is_type(exp.DataType.Type.BINARY, exp.DataType.Type.UNKNOWN):
 363        annotated.type = exp.DataType.Type.VARCHAR
 364
 365    return annotated
 366
 367
 368class BigQuery(Dialect):
 369    WEEK_OFFSET = -1
 370    UNNEST_COLUMN_ONLY = True
 371    SUPPORTS_USER_DEFINED_TYPES = False
 372    SUPPORTS_SEMI_ANTI_JOIN = False
 373    LOG_BASE_FIRST = False
 374    HEX_LOWERCASE = True
 375    FORCE_EARLY_ALIAS_REF_EXPANSION = True
 376    PRESERVE_ORIGINAL_NAMES = True
 377    HEX_STRING_IS_INTEGER_TYPE = True
 378
 379    # https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#case_sensitivity
 380    NORMALIZATION_STRATEGY = NormalizationStrategy.CASE_INSENSITIVE
 381
 382    # bigquery udfs are case sensitive
 383    NORMALIZE_FUNCTIONS = False
 384
 385    # https://cloud.google.com/bigquery/docs/reference/standard-sql/format-elements#format_elements_date_time
 386    TIME_MAPPING = {
 387        "%D": "%m/%d/%y",
 388        "%E6S": "%S.%f",
 389        "%e": "%-d",
 390    }
 391
 392    FORMAT_MAPPING = {
 393        "DD": "%d",
 394        "MM": "%m",
 395        "MON": "%b",
 396        "MONTH": "%B",
 397        "YYYY": "%Y",
 398        "YY": "%y",
 399        "HH": "%I",
 400        "HH12": "%I",
 401        "HH24": "%H",
 402        "MI": "%M",
 403        "SS": "%S",
 404        "SSSSS": "%f",
 405        "TZH": "%z",
 406    }
 407
 408    # The _PARTITIONTIME and _PARTITIONDATE pseudo-columns are not returned by a SELECT * statement
 409    # https://cloud.google.com/bigquery/docs/querying-partitioned-tables#query_an_ingestion-time_partitioned_table
 410    PSEUDOCOLUMNS = {"_PARTITIONTIME", "_PARTITIONDATE"}
 411
 412    # All set operations require either a DISTINCT or ALL specifier
 413    SET_OP_DISTINCT_BY_DEFAULT = dict.fromkeys((exp.Except, exp.Intersect, exp.Union), None)
 414
 415    # BigQuery maps Type.TIMESTAMP to DATETIME, so we need to amend the inferred types
 416    TYPE_TO_EXPRESSIONS = {
 417        **Dialect.TYPE_TO_EXPRESSIONS,
 418        exp.DataType.Type.TIMESTAMPTZ: Dialect.TYPE_TO_EXPRESSIONS[exp.DataType.Type.TIMESTAMP],
 419    }
 420    TYPE_TO_EXPRESSIONS.pop(exp.DataType.Type.TIMESTAMP)
 421
 422    ANNOTATORS = {
 423        **Dialect.ANNOTATORS,
 424        **{
 425            expr_type: annotate_with_type_lambda(data_type)
 426            for data_type, expressions in TYPE_TO_EXPRESSIONS.items()
 427            for expr_type in expressions
 428        },
 429        **{
 430            expr_type: lambda self, e: _annotate_math_functions(self, e)
 431            for expr_type in (exp.Floor, exp.Ceil, exp.Log, exp.Ln, exp.Sqrt, exp.Exp, exp.Round)
 432        },
 433        **{
 434            expr_type: lambda self, e: self._annotate_by_args(e, "this")
 435            for expr_type in (
 436                exp.Left,
 437                exp.Right,
 438                exp.Lower,
 439                exp.Upper,
 440                exp.Pad,
 441                exp.Trim,
 442                exp.RegexpExtract,
 443                exp.RegexpReplace,
 444                exp.Repeat,
 445                exp.Substring,
 446            )
 447        },
 448        exp.ArrayConcat: lambda self, e: self._annotate_by_args(e, "this", "expressions"),
 449        exp.Ascii: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.BIGINT),
 450        exp.BitwiseAndAgg: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.BIGINT),
 451        exp.BitwiseOrAgg: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.BIGINT),
 452        exp.BitwiseXorAgg: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.BIGINT),
 453        exp.BitwiseCountAgg: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.BIGINT),
 454        exp.Concat: _annotate_concat,
 455        exp.Corr: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.DOUBLE),
 456        exp.CovarPop: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.DOUBLE),
 457        exp.CovarSamp: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.DOUBLE),
 458        exp.JSONArray: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.JSON),
 459        exp.JSONExtractScalar: lambda self, e: self._annotate_with_type(
 460            e, exp.DataType.Type.VARCHAR
 461        ),
 462        exp.JSONValueArray: lambda self, e: self._annotate_with_type(
 463            e, exp.DataType.build("ARRAY<VARCHAR>")
 464        ),
 465        exp.JSONType: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.VARCHAR),
 466        exp.Lag: lambda self, e: self._annotate_by_args(e, "this", "default"),
 467        exp.SHA: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.BINARY),
 468        exp.SHA2: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.BINARY),
 469        exp.Sign: lambda self, e: self._annotate_by_args(e, "this"),
 470        exp.Split: lambda self, e: self._annotate_by_args(e, "this", array=True),
 471        exp.TimestampFromParts: lambda self, e: self._annotate_with_type(
 472            e, exp.DataType.Type.DATETIME
 473        ),
 474        exp.Unicode: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.BIGINT),
 475    }
 476
 477    def normalize_identifier(self, expression: E) -> E:
 478        if (
 479            isinstance(expression, exp.Identifier)
 480            and self.normalization_strategy is NormalizationStrategy.CASE_INSENSITIVE
 481        ):
 482            parent = expression.parent
 483            while isinstance(parent, exp.Dot):
 484                parent = parent.parent
 485
 486            # In BigQuery, CTEs are case-insensitive, but UDF and table names are case-sensitive
 487            # by default. The following check uses a heuristic to detect tables based on whether
 488            # they are qualified. This should generally be correct, because tables in BigQuery
 489            # must be qualified with at least a dataset, unless @@dataset_id is set.
 490            case_sensitive = (
 491                isinstance(parent, exp.UserDefinedFunction)
 492                or (
 493                    isinstance(parent, exp.Table)
 494                    and parent.db
 495                    and (parent.meta.get("quoted_table") or not parent.meta.get("maybe_column"))
 496                )
 497                or expression.meta.get("is_table")
 498            )
 499            if not case_sensitive:
 500                expression.set("this", expression.this.lower())
 501
 502            return t.cast(E, expression)
 503
 504        return super().normalize_identifier(expression)
 505
 506    class Tokenizer(tokens.Tokenizer):
 507        QUOTES = ["'", '"', '"""', "'''"]
 508        COMMENTS = ["--", "#", ("/*", "*/")]
 509        IDENTIFIERS = ["`"]
 510        STRING_ESCAPES = ["\\"]
 511
 512        HEX_STRINGS = [("0x", ""), ("0X", "")]
 513
 514        BYTE_STRINGS = [
 515            (prefix + q, q) for q in t.cast(t.List[str], QUOTES) for prefix in ("b", "B")
 516        ]
 517
 518        RAW_STRINGS = [
 519            (prefix + q, q) for q in t.cast(t.List[str], QUOTES) for prefix in ("r", "R")
 520        ]
 521
 522        NESTED_COMMENTS = False
 523
 524        KEYWORDS = {
 525            **tokens.Tokenizer.KEYWORDS,
 526            "ANY TYPE": TokenType.VARIANT,
 527            "BEGIN": TokenType.COMMAND,
 528            "BEGIN TRANSACTION": TokenType.BEGIN,
 529            "BYTEINT": TokenType.INT,
 530            "BYTES": TokenType.BINARY,
 531            "CURRENT_DATETIME": TokenType.CURRENT_DATETIME,
 532            "DATETIME": TokenType.TIMESTAMP,
 533            "DECLARE": TokenType.COMMAND,
 534            "ELSEIF": TokenType.COMMAND,
 535            "EXCEPTION": TokenType.COMMAND,
 536            "EXPORT": TokenType.EXPORT,
 537            "FLOAT64": TokenType.DOUBLE,
 538            "FOR SYSTEM_TIME": TokenType.TIMESTAMP_SNAPSHOT,
 539            "MODEL": TokenType.MODEL,
 540            "NOT DETERMINISTIC": TokenType.VOLATILE,
 541            "RECORD": TokenType.STRUCT,
 542            "TIMESTAMP": TokenType.TIMESTAMPTZ,
 543        }
 544        KEYWORDS.pop("DIV")
 545        KEYWORDS.pop("VALUES")
 546        KEYWORDS.pop("/*+")
 547
 548    class Parser(parser.Parser):
 549        PREFIXED_PIVOT_COLUMNS = True
 550        LOG_DEFAULTS_TO_LN = True
 551        SUPPORTS_IMPLICIT_UNNEST = True
 552        JOINS_HAVE_EQUAL_PRECEDENCE = True
 553
 554        # BigQuery does not allow ASC/DESC to be used as an identifier
 555        ID_VAR_TOKENS = parser.Parser.ID_VAR_TOKENS - {TokenType.ASC, TokenType.DESC}
 556        ALIAS_TOKENS = parser.Parser.ALIAS_TOKENS - {TokenType.ASC, TokenType.DESC}
 557        TABLE_ALIAS_TOKENS = parser.Parser.TABLE_ALIAS_TOKENS - {TokenType.ASC, TokenType.DESC}
 558        COMMENT_TABLE_ALIAS_TOKENS = parser.Parser.COMMENT_TABLE_ALIAS_TOKENS - {
 559            TokenType.ASC,
 560            TokenType.DESC,
 561        }
 562        UPDATE_ALIAS_TOKENS = parser.Parser.UPDATE_ALIAS_TOKENS - {TokenType.ASC, TokenType.DESC}
 563
 564        FUNCTIONS = {
 565            **parser.Parser.FUNCTIONS,
 566            "CONTAINS_SUBSTR": _build_contains_substring,
 567            "DATE": _build_date,
 568            "DATE_ADD": build_date_delta_with_interval(exp.DateAdd),
 569            "DATE_SUB": build_date_delta_with_interval(exp.DateSub),
 570            "DATE_TRUNC": lambda args: exp.DateTrunc(
 571                unit=seq_get(args, 1),
 572                this=seq_get(args, 0),
 573                zone=seq_get(args, 2),
 574            ),
 575            "DATETIME": _build_datetime,
 576            "DATETIME_ADD": build_date_delta_with_interval(exp.DatetimeAdd),
 577            "DATETIME_SUB": build_date_delta_with_interval(exp.DatetimeSub),
 578            "DIV": binary_from_function(exp.IntDiv),
 579            "EDIT_DISTANCE": _build_levenshtein,
 580            "FORMAT_DATE": _build_format_time(exp.TsOrDsToDate),
 581            "GENERATE_ARRAY": exp.GenerateSeries.from_arg_list,
 582            "JSON_EXTRACT_SCALAR": _build_extract_json_with_default_path(exp.JSONExtractScalar),
 583            "JSON_EXTRACT_ARRAY": _build_extract_json_with_default_path(exp.JSONExtractArray),
 584            "JSON_QUERY": parser.build_extract_json_with_path(exp.JSONExtract),
 585            "JSON_QUERY_ARRAY": _build_extract_json_with_default_path(exp.JSONExtractArray),
 586            "JSON_VALUE": _build_extract_json_with_default_path(exp.JSONExtractScalar),
 587            "JSON_VALUE_ARRAY": _build_extract_json_with_default_path(exp.JSONValueArray),
 588            "LENGTH": lambda args: exp.Length(this=seq_get(args, 0), binary=True),
 589            "MD5": exp.MD5Digest.from_arg_list,
 590            "TO_HEX": _build_to_hex,
 591            "PARSE_DATE": lambda args: build_formatted_time(exp.StrToDate, "bigquery")(
 592                [seq_get(args, 1), seq_get(args, 0)]
 593            ),
 594            "PARSE_TIMESTAMP": _build_parse_timestamp,
 595            "REGEXP_CONTAINS": exp.RegexpLike.from_arg_list,
 596            "REGEXP_EXTRACT": _build_regexp_extract(exp.RegexpExtract),
 597            "REGEXP_SUBSTR": _build_regexp_extract(exp.RegexpExtract),
 598            "REGEXP_EXTRACT_ALL": _build_regexp_extract(
 599                exp.RegexpExtractAll, default_group=exp.Literal.number(0)
 600            ),
 601            "SHA256": lambda args: exp.SHA2(this=seq_get(args, 0), length=exp.Literal.number(256)),
 602            "SHA512": lambda args: exp.SHA2(this=seq_get(args, 0), length=exp.Literal.number(512)),
 603            "SPLIT": lambda args: exp.Split(
 604                # https://cloud.google.com/bigquery/docs/reference/standard-sql/string_functions#split
 605                this=seq_get(args, 0),
 606                expression=seq_get(args, 1) or exp.Literal.string(","),
 607            ),
 608            "STRPOS": exp.StrPosition.from_arg_list,
 609            "TIME": _build_time,
 610            "TIME_ADD": build_date_delta_with_interval(exp.TimeAdd),
 611            "TIME_SUB": build_date_delta_with_interval(exp.TimeSub),
 612            "TIMESTAMP": _build_timestamp,
 613            "TIMESTAMP_ADD": build_date_delta_with_interval(exp.TimestampAdd),
 614            "TIMESTAMP_SUB": build_date_delta_with_interval(exp.TimestampSub),
 615            "TIMESTAMP_MICROS": lambda args: exp.UnixToTime(
 616                this=seq_get(args, 0), scale=exp.UnixToTime.MICROS
 617            ),
 618            "TIMESTAMP_MILLIS": lambda args: exp.UnixToTime(
 619                this=seq_get(args, 0), scale=exp.UnixToTime.MILLIS
 620            ),
 621            "TIMESTAMP_SECONDS": lambda args: exp.UnixToTime(this=seq_get(args, 0)),
 622            "TO_JSON_STRING": exp.JSONFormat.from_arg_list,
 623            "FORMAT_DATETIME": _build_format_time(exp.TsOrDsToDatetime),
 624            "FORMAT_TIMESTAMP": _build_format_time(exp.TsOrDsToTimestamp),
 625        }
 626
 627        FUNCTION_PARSERS = {
 628            **parser.Parser.FUNCTION_PARSERS,
 629            "ARRAY": lambda self: self.expression(exp.Array, expressions=[self._parse_statement()]),
 630            "JSON_ARRAY": lambda self: self.expression(
 631                exp.JSONArray, expressions=self._parse_csv(self._parse_bitwise)
 632            ),
 633            "MAKE_INTERVAL": lambda self: self._parse_make_interval(),
 634            "FEATURES_AT_TIME": lambda self: self._parse_features_at_time(),
 635        }
 636        FUNCTION_PARSERS.pop("TRIM")
 637
 638        NO_PAREN_FUNCTIONS = {
 639            **parser.Parser.NO_PAREN_FUNCTIONS,
 640            TokenType.CURRENT_DATETIME: exp.CurrentDatetime,
 641        }
 642
 643        NESTED_TYPE_TOKENS = {
 644            *parser.Parser.NESTED_TYPE_TOKENS,
 645            TokenType.TABLE,
 646        }
 647
 648        PROPERTY_PARSERS = {
 649            **parser.Parser.PROPERTY_PARSERS,
 650            "NOT DETERMINISTIC": lambda self: self.expression(
 651                exp.StabilityProperty, this=exp.Literal.string("VOLATILE")
 652            ),
 653            "OPTIONS": lambda self: self._parse_with_property(),
 654        }
 655
 656        CONSTRAINT_PARSERS = {
 657            **parser.Parser.CONSTRAINT_PARSERS,
 658            "OPTIONS": lambda self: exp.Properties(expressions=self._parse_with_property()),
 659        }
 660
 661        RANGE_PARSERS = parser.Parser.RANGE_PARSERS.copy()
 662        RANGE_PARSERS.pop(TokenType.OVERLAPS)
 663
 664        NULL_TOKENS = {TokenType.NULL, TokenType.UNKNOWN}
 665
 666        DASHED_TABLE_PART_FOLLOW_TOKENS = {TokenType.DOT, TokenType.L_PAREN, TokenType.R_PAREN}
 667
 668        STATEMENT_PARSERS = {
 669            **parser.Parser.STATEMENT_PARSERS,
 670            TokenType.ELSE: lambda self: self._parse_as_command(self._prev),
 671            TokenType.END: lambda self: self._parse_as_command(self._prev),
 672            TokenType.FOR: lambda self: self._parse_for_in(),
 673            TokenType.EXPORT: lambda self: self._parse_export_data(),
 674        }
 675
 676        BRACKET_OFFSETS = {
 677            "OFFSET": (0, False),
 678            "ORDINAL": (1, False),
 679            "SAFE_OFFSET": (0, True),
 680            "SAFE_ORDINAL": (1, True),
 681        }
 682
 683        def _parse_for_in(self) -> exp.ForIn:
 684            this = self._parse_range()
 685            self._match_text_seq("DO")
 686            return self.expression(exp.ForIn, this=this, expression=self._parse_statement())
 687
 688        def _parse_table_part(self, schema: bool = False) -> t.Optional[exp.Expression]:
 689            this = super()._parse_table_part(schema=schema) or self._parse_number()
 690
 691            # https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#table_names
 692            if isinstance(this, exp.Identifier):
 693                table_name = this.name
 694                while self._match(TokenType.DASH, advance=False) and self._next:
 695                    start = self._curr
 696                    while self._is_connected() and not self._match_set(
 697                        self.DASHED_TABLE_PART_FOLLOW_TOKENS, advance=False
 698                    ):
 699                        self._advance()
 700
 701                    if start == self._curr:
 702                        break
 703
 704                    table_name += self._find_sql(start, self._prev)
 705
 706                this = exp.Identifier(
 707                    this=table_name, quoted=this.args.get("quoted")
 708                ).update_positions(this)
 709            elif isinstance(this, exp.Literal):
 710                table_name = this.name
 711
 712                if self._is_connected() and self._parse_var(any_token=True):
 713                    table_name += self._prev.text
 714
 715                this = exp.Identifier(this=table_name, quoted=True).update_positions(this)
 716
 717            return this
 718
 719        def _parse_table_parts(
 720            self, schema: bool = False, is_db_reference: bool = False, wildcard: bool = False
 721        ) -> exp.Table:
 722            table = super()._parse_table_parts(
 723                schema=schema, is_db_reference=is_db_reference, wildcard=True
 724            )
 725
 726            # proj-1.db.tbl -- `1.` is tokenized as a float so we need to unravel it here
 727            if not table.catalog:
 728                if table.db:
 729                    previous_db = table.args["db"]
 730                    parts = table.db.split(".")
 731                    if len(parts) == 2 and not table.args["db"].quoted:
 732                        table.set(
 733                            "catalog", exp.Identifier(this=parts[0]).update_positions(previous_db)
 734                        )
 735                        table.set("db", exp.Identifier(this=parts[1]).update_positions(previous_db))
 736                else:
 737                    previous_this = table.this
 738                    parts = table.name.split(".")
 739                    if len(parts) == 2 and not table.this.quoted:
 740                        table.set(
 741                            "db", exp.Identifier(this=parts[0]).update_positions(previous_this)
 742                        )
 743                        table.set(
 744                            "this", exp.Identifier(this=parts[1]).update_positions(previous_this)
 745                        )
 746
 747            if isinstance(table.this, exp.Identifier) and any("." in p.name for p in table.parts):
 748                alias = table.this
 749                catalog, db, this, *rest = (
 750                    exp.to_identifier(p, quoted=True)
 751                    for p in split_num_words(".".join(p.name for p in table.parts), ".", 3)
 752                )
 753
 754                for part in (catalog, db, this):
 755                    if part:
 756                        part.update_positions(table.this)
 757
 758                if rest and this:
 759                    this = exp.Dot.build([this, *rest])  # type: ignore
 760
 761                table = exp.Table(
 762                    this=this, db=db, catalog=catalog, pivots=table.args.get("pivots")
 763                )
 764                table.meta["quoted_table"] = True
 765            else:
 766                alias = None
 767
 768            # The `INFORMATION_SCHEMA` views in BigQuery need to be qualified by a region or
 769            # dataset, so if the project identifier is omitted we need to fix the ast so that
 770            # the `INFORMATION_SCHEMA.X` bit is represented as a single (quoted) Identifier.
 771            # Otherwise, we wouldn't correctly qualify a `Table` node that references these
 772            # views, because it would seem like the "catalog" part is set, when it'd actually
 773            # be the region/dataset. Merging the two identifiers into a single one is done to
 774            # avoid producing a 4-part Table reference, which would cause issues in the schema
 775            # module, when there are 3-part table names mixed with information schema views.
 776            #
 777            # See: https://cloud.google.com/bigquery/docs/information-schema-intro#syntax
 778            table_parts = table.parts
 779            if len(table_parts) > 1 and table_parts[-2].name.upper() == "INFORMATION_SCHEMA":
 780                # We need to alias the table here to avoid breaking existing qualified columns.
 781                # This is expected to be safe, because if there's an actual alias coming up in
 782                # the token stream, it will overwrite this one. If there isn't one, we are only
 783                # exposing the name that can be used to reference the view explicitly (a no-op).
 784                exp.alias_(
 785                    table,
 786                    t.cast(exp.Identifier, alias or table_parts[-1]),
 787                    table=True,
 788                    copy=False,
 789                )
 790
 791                info_schema_view = f"{table_parts[-2].name}.{table_parts[-1].name}"
 792                new_this = exp.Identifier(this=info_schema_view, quoted=True).update_positions(
 793                    line=table_parts[-2].meta.get("line"),
 794                    col=table_parts[-1].meta.get("col"),
 795                    start=table_parts[-2].meta.get("start"),
 796                    end=table_parts[-1].meta.get("end"),
 797                )
 798                table.set("this", new_this)
 799                table.set("db", seq_get(table_parts, -3))
 800                table.set("catalog", seq_get(table_parts, -4))
 801
 802            return table
 803
 804        def _parse_column(self) -> t.Optional[exp.Expression]:
 805            column = super()._parse_column()
 806            if isinstance(column, exp.Column):
 807                parts = column.parts
 808                if any("." in p.name for p in parts):
 809                    catalog, db, table, this, *rest = (
 810                        exp.to_identifier(p, quoted=True)
 811                        for p in split_num_words(".".join(p.name for p in parts), ".", 4)
 812                    )
 813
 814                    if rest and this:
 815                        this = exp.Dot.build([this, *rest])  # type: ignore
 816
 817                    column = exp.Column(this=this, table=table, db=db, catalog=catalog)
 818                    column.meta["quoted_column"] = True
 819
 820            return column
 821
 822        @t.overload
 823        def _parse_json_object(self, agg: Lit[False]) -> exp.JSONObject: ...
 824
 825        @t.overload
 826        def _parse_json_object(self, agg: Lit[True]) -> exp.JSONObjectAgg: ...
 827
 828        def _parse_json_object(self, agg=False):
 829            json_object = super()._parse_json_object()
 830            array_kv_pair = seq_get(json_object.expressions, 0)
 831
 832            # Converts BQ's "signature 2" of JSON_OBJECT into SQLGlot's canonical representation
 833            # https://cloud.google.com/bigquery/docs/reference/standard-sql/json_functions#json_object_signature2
 834            if (
 835                array_kv_pair
 836                and isinstance(array_kv_pair.this, exp.Array)
 837                and isinstance(array_kv_pair.expression, exp.Array)
 838            ):
 839                keys = array_kv_pair.this.expressions
 840                values = array_kv_pair.expression.expressions
 841
 842                json_object.set(
 843                    "expressions",
 844                    [exp.JSONKeyValue(this=k, expression=v) for k, v in zip(keys, values)],
 845                )
 846
 847            return json_object
 848
 849        def _parse_bracket(
 850            self, this: t.Optional[exp.Expression] = None
 851        ) -> t.Optional[exp.Expression]:
 852            bracket = super()._parse_bracket(this)
 853
 854            if this is bracket:
 855                return bracket
 856
 857            if isinstance(bracket, exp.Bracket):
 858                for expression in bracket.expressions:
 859                    name = expression.name.upper()
 860
 861                    if name not in self.BRACKET_OFFSETS:
 862                        break
 863
 864                    offset, safe = self.BRACKET_OFFSETS[name]
 865                    bracket.set("offset", offset)
 866                    bracket.set("safe", safe)
 867                    expression.replace(expression.expressions[0])
 868
 869            return bracket
 870
 871        def _parse_unnest(self, with_alias: bool = True) -> t.Optional[exp.Unnest]:
 872            unnest = super()._parse_unnest(with_alias=with_alias)
 873
 874            if not unnest:
 875                return None
 876
 877            unnest_expr = seq_get(unnest.expressions, 0)
 878            if unnest_expr:
 879                from sqlglot.optimizer.annotate_types import annotate_types
 880
 881                unnest_expr = annotate_types(unnest_expr, dialect=self.dialect)
 882
 883                # Unnesting a nested array (i.e array of structs) explodes the top-level struct fields,
 884                # in contrast to other dialects such as DuckDB which flattens only the array by default
 885                if unnest_expr.is_type(exp.DataType.Type.ARRAY) and any(
 886                    array_elem.is_type(exp.DataType.Type.STRUCT)
 887                    for array_elem in unnest_expr._type.expressions
 888                ):
 889                    unnest.set("explode_array", True)
 890
 891            return unnest
 892
 893        def _parse_make_interval(self) -> exp.MakeInterval:
 894            expr = exp.MakeInterval()
 895
 896            for arg_key in expr.arg_types:
 897                value = self._parse_lambda()
 898
 899                if not value:
 900                    break
 901
 902                # Non-named arguments are filled sequentially, (optionally) followed by named arguments
 903                # that can appear in any order e.g MAKE_INTERVAL(1, minute => 5, day => 2)
 904                if isinstance(value, exp.Kwarg):
 905                    arg_key = value.this.name
 906
 907                expr.set(arg_key, value)
 908
 909                self._match(TokenType.COMMA)
 910
 911            return expr
 912
 913        def _parse_features_at_time(self) -> exp.FeaturesAtTime:
 914            expr = self.expression(
 915                exp.FeaturesAtTime,
 916                this=(self._match(TokenType.TABLE) and self._parse_table())
 917                or self._parse_select(nested=True),
 918            )
 919
 920            while self._match(TokenType.COMMA):
 921                arg = self._parse_lambda()
 922
 923                # Get the LHS of the Kwarg and set the arg to that value, e.g
 924                # "num_rows => 1" sets the expr's `num_rows` arg
 925                if arg:
 926                    expr.set(arg.this.name, arg)
 927
 928            return expr
 929
 930        def _parse_export_data(self) -> exp.Export:
 931            self._match_text_seq("DATA")
 932
 933            return self.expression(
 934                exp.Export,
 935                connection=self._match_text_seq("WITH", "CONNECTION") and self._parse_table_parts(),
 936                options=self._parse_properties(),
 937                this=self._match_text_seq("AS") and self._parse_select(),
 938            )
 939
 940    class Generator(generator.Generator):
 941        INTERVAL_ALLOWS_PLURAL_FORM = False
 942        JOIN_HINTS = False
 943        QUERY_HINTS = False
 944        TABLE_HINTS = False
 945        LIMIT_FETCH = "LIMIT"
 946        RENAME_TABLE_WITH_DB = False
 947        NVL2_SUPPORTED = False
 948        UNNEST_WITH_ORDINALITY = False
 949        COLLATE_IS_FUNC = True
 950        LIMIT_ONLY_LITERALS = True
 951        SUPPORTS_TABLE_ALIAS_COLUMNS = False
 952        UNPIVOT_ALIASES_ARE_IDENTIFIERS = False
 953        JSON_KEY_VALUE_PAIR_SEP = ","
 954        NULL_ORDERING_SUPPORTED = False
 955        IGNORE_NULLS_IN_FUNC = True
 956        JSON_PATH_SINGLE_QUOTE_ESCAPE = True
 957        CAN_IMPLEMENT_ARRAY_ANY = True
 958        SUPPORTS_TO_NUMBER = False
 959        NAMED_PLACEHOLDER_TOKEN = "@"
 960        HEX_FUNC = "TO_HEX"
 961        WITH_PROPERTIES_PREFIX = "OPTIONS"
 962        SUPPORTS_EXPLODING_PROJECTIONS = False
 963        EXCEPT_INTERSECT_SUPPORT_ALL_CLAUSE = False
 964        SUPPORTS_UNIX_SECONDS = True
 965
 966        TRANSFORMS = {
 967            **generator.Generator.TRANSFORMS,
 968            exp.ApproxDistinct: rename_func("APPROX_COUNT_DISTINCT"),
 969            exp.ArgMax: arg_max_or_min_no_count("MAX_BY"),
 970            exp.ArgMin: arg_max_or_min_no_count("MIN_BY"),
 971            exp.Array: inline_array_unless_query,
 972            exp.ArrayContains: _array_contains_sql,
 973            exp.ArrayFilter: filter_array_using_unnest,
 974            exp.ArrayRemove: filter_array_using_unnest,
 975            exp.Cast: transforms.preprocess([transforms.remove_precision_parameterized_types]),
 976            exp.CollateProperty: lambda self, e: (
 977                f"DEFAULT COLLATE {self.sql(e, 'this')}"
 978                if e.args.get("default")
 979                else f"COLLATE {self.sql(e, 'this')}"
 980            ),
 981            exp.Commit: lambda *_: "COMMIT TRANSACTION",
 982            exp.CountIf: rename_func("COUNTIF"),
 983            exp.Create: _create_sql,
 984            exp.CTE: transforms.preprocess([_pushdown_cte_column_names]),
 985            exp.DateAdd: date_add_interval_sql("DATE", "ADD"),
 986            exp.DateDiff: lambda self, e: self.func(
 987                "DATE_DIFF", e.this, e.expression, unit_to_var(e)
 988            ),
 989            exp.DateFromParts: rename_func("DATE"),
 990            exp.DateStrToDate: datestrtodate_sql,
 991            exp.DateSub: date_add_interval_sql("DATE", "SUB"),
 992            exp.DatetimeAdd: date_add_interval_sql("DATETIME", "ADD"),
 993            exp.DatetimeSub: date_add_interval_sql("DATETIME", "SUB"),
 994            exp.FromTimeZone: lambda self, e: self.func(
 995                "DATETIME", self.func("TIMESTAMP", e.this, e.args.get("zone")), "'UTC'"
 996            ),
 997            exp.GenerateSeries: rename_func("GENERATE_ARRAY"),
 998            exp.GroupConcat: lambda self, e: groupconcat_sql(
 999                self, e, func_name="STRING_AGG", within_group=False
1000            ),
1001            exp.Hex: lambda self, e: self.func("UPPER", self.func("TO_HEX", self.sql(e, "this"))),
1002            exp.HexString: lambda self, e: self.hexstring_sql(e, binary_function_repr="FROM_HEX"),
1003            exp.If: if_sql(false_value="NULL"),
1004            exp.ILike: no_ilike_sql,
1005            exp.IntDiv: rename_func("DIV"),
1006            exp.Int64: rename_func("INT64"),
1007            exp.JSONExtract: _json_extract_sql,
1008            exp.JSONExtractArray: _json_extract_sql,
1009            exp.JSONExtractScalar: _json_extract_sql,
1010            exp.JSONFormat: rename_func("TO_JSON_STRING"),
1011            exp.Levenshtein: _levenshtein_sql,
1012            exp.Max: max_or_greatest,
1013            exp.MD5: lambda self, e: self.func("TO_HEX", self.func("MD5", e.this)),
1014            exp.MD5Digest: rename_func("MD5"),
1015            exp.Min: min_or_least,
1016            exp.PartitionedByProperty: lambda self, e: f"PARTITION BY {self.sql(e, 'this')}",
1017            exp.RegexpExtract: lambda self, e: self.func(
1018                "REGEXP_EXTRACT",
1019                e.this,
1020                e.expression,
1021                e.args.get("position"),
1022                e.args.get("occurrence"),
1023            ),
1024            exp.RegexpExtractAll: lambda self, e: self.func(
1025                "REGEXP_EXTRACT_ALL", e.this, e.expression
1026            ),
1027            exp.RegexpReplace: regexp_replace_sql,
1028            exp.RegexpLike: rename_func("REGEXP_CONTAINS"),
1029            exp.ReturnsProperty: _returnsproperty_sql,
1030            exp.Rollback: lambda *_: "ROLLBACK TRANSACTION",
1031            exp.Select: transforms.preprocess(
1032                [
1033                    transforms.explode_projection_to_unnest(),
1034                    transforms.unqualify_unnest,
1035                    transforms.eliminate_distinct_on,
1036                    _alias_ordered_group,
1037                    transforms.eliminate_semi_and_anti_joins,
1038                ]
1039            ),
1040            exp.SHA: rename_func("SHA1"),
1041            exp.SHA2: sha256_sql,
1042            exp.Space: space_sql,
1043            exp.StabilityProperty: lambda self, e: (
1044                "DETERMINISTIC" if e.name == "IMMUTABLE" else "NOT DETERMINISTIC"
1045            ),
1046            exp.String: rename_func("STRING"),
1047            exp.StrPosition: lambda self, e: (
1048                strposition_sql(
1049                    self, e, func_name="INSTR", supports_position=True, supports_occurrence=True
1050                )
1051            ),
1052            exp.StrToDate: _str_to_datetime_sql,
1053            exp.StrToTime: _str_to_datetime_sql,
1054            exp.TimeAdd: date_add_interval_sql("TIME", "ADD"),
1055            exp.TimeFromParts: rename_func("TIME"),
1056            exp.TimestampFromParts: rename_func("DATETIME"),
1057            exp.TimeSub: date_add_interval_sql("TIME", "SUB"),
1058            exp.TimestampAdd: date_add_interval_sql("TIMESTAMP", "ADD"),
1059            exp.TimestampDiff: rename_func("TIMESTAMP_DIFF"),
1060            exp.TimestampSub: date_add_interval_sql("TIMESTAMP", "SUB"),
1061            exp.TimeStrToTime: timestrtotime_sql,
1062            exp.Transaction: lambda *_: "BEGIN TRANSACTION",
1063            exp.TsOrDsAdd: _ts_or_ds_add_sql,
1064            exp.TsOrDsDiff: _ts_or_ds_diff_sql,
1065            exp.TsOrDsToTime: rename_func("TIME"),
1066            exp.TsOrDsToDatetime: rename_func("DATETIME"),
1067            exp.TsOrDsToTimestamp: rename_func("TIMESTAMP"),
1068            exp.Unhex: rename_func("FROM_HEX"),
1069            exp.UnixDate: rename_func("UNIX_DATE"),
1070            exp.UnixToTime: _unix_to_time_sql,
1071            exp.Uuid: lambda *_: "GENERATE_UUID()",
1072            exp.Values: _derived_table_values_to_unnest,
1073            exp.VariancePop: rename_func("VAR_POP"),
1074            exp.SafeDivide: rename_func("SAFE_DIVIDE"),
1075        }
1076
1077        SUPPORTED_JSON_PATH_PARTS = {
1078            exp.JSONPathKey,
1079            exp.JSONPathRoot,
1080            exp.JSONPathSubscript,
1081        }
1082
1083        TYPE_MAPPING = {
1084            **generator.Generator.TYPE_MAPPING,
1085            exp.DataType.Type.BIGDECIMAL: "BIGNUMERIC",
1086            exp.DataType.Type.BIGINT: "INT64",
1087            exp.DataType.Type.BINARY: "BYTES",
1088            exp.DataType.Type.BLOB: "BYTES",
1089            exp.DataType.Type.BOOLEAN: "BOOL",
1090            exp.DataType.Type.CHAR: "STRING",
1091            exp.DataType.Type.DECIMAL: "NUMERIC",
1092            exp.DataType.Type.DOUBLE: "FLOAT64",
1093            exp.DataType.Type.FLOAT: "FLOAT64",
1094            exp.DataType.Type.INT: "INT64",
1095            exp.DataType.Type.NCHAR: "STRING",
1096            exp.DataType.Type.NVARCHAR: "STRING",
1097            exp.DataType.Type.SMALLINT: "INT64",
1098            exp.DataType.Type.TEXT: "STRING",
1099            exp.DataType.Type.TIMESTAMP: "DATETIME",
1100            exp.DataType.Type.TIMESTAMPNTZ: "DATETIME",
1101            exp.DataType.Type.TIMESTAMPTZ: "TIMESTAMP",
1102            exp.DataType.Type.TIMESTAMPLTZ: "TIMESTAMP",
1103            exp.DataType.Type.TINYINT: "INT64",
1104            exp.DataType.Type.ROWVERSION: "BYTES",
1105            exp.DataType.Type.UUID: "STRING",
1106            exp.DataType.Type.VARBINARY: "BYTES",
1107            exp.DataType.Type.VARCHAR: "STRING",
1108            exp.DataType.Type.VARIANT: "ANY TYPE",
1109        }
1110
1111        PROPERTIES_LOCATION = {
1112            **generator.Generator.PROPERTIES_LOCATION,
1113            exp.PartitionedByProperty: exp.Properties.Location.POST_SCHEMA,
1114            exp.VolatileProperty: exp.Properties.Location.UNSUPPORTED,
1115        }
1116
1117        # WINDOW comes after QUALIFY
1118        # https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#window_clause
1119        AFTER_HAVING_MODIFIER_TRANSFORMS = {
1120            "qualify": generator.Generator.AFTER_HAVING_MODIFIER_TRANSFORMS["qualify"],
1121            "windows": generator.Generator.AFTER_HAVING_MODIFIER_TRANSFORMS["windows"],
1122        }
1123
1124        # from: https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#reserved_keywords
1125        RESERVED_KEYWORDS = {
1126            "all",
1127            "and",
1128            "any",
1129            "array",
1130            "as",
1131            "asc",
1132            "assert_rows_modified",
1133            "at",
1134            "between",
1135            "by",
1136            "case",
1137            "cast",
1138            "collate",
1139            "contains",
1140            "create",
1141            "cross",
1142            "cube",
1143            "current",
1144            "default",
1145            "define",
1146            "desc",
1147            "distinct",
1148            "else",
1149            "end",
1150            "enum",
1151            "escape",
1152            "except",
1153            "exclude",
1154            "exists",
1155            "extract",
1156            "false",
1157            "fetch",
1158            "following",
1159            "for",
1160            "from",
1161            "full",
1162            "group",
1163            "grouping",
1164            "groups",
1165            "hash",
1166            "having",
1167            "if",
1168            "ignore",
1169            "in",
1170            "inner",
1171            "intersect",
1172            "interval",
1173            "into",
1174            "is",
1175            "join",
1176            "lateral",
1177            "left",
1178            "like",
1179            "limit",
1180            "lookup",
1181            "merge",
1182            "natural",
1183            "new",
1184            "no",
1185            "not",
1186            "null",
1187            "nulls",
1188            "of",
1189            "on",
1190            "or",
1191            "order",
1192            "outer",
1193            "over",
1194            "partition",
1195            "preceding",
1196            "proto",
1197            "qualify",
1198            "range",
1199            "recursive",
1200            "respect",
1201            "right",
1202            "rollup",
1203            "rows",
1204            "select",
1205            "set",
1206            "some",
1207            "struct",
1208            "tablesample",
1209            "then",
1210            "to",
1211            "treat",
1212            "true",
1213            "unbounded",
1214            "union",
1215            "unnest",
1216            "using",
1217            "when",
1218            "where",
1219            "window",
1220            "with",
1221            "within",
1222        }
1223
1224        def datetrunc_sql(self, expression: exp.DateTrunc) -> str:
1225            unit = expression.unit
1226            unit_sql = unit.name if unit.is_string else self.sql(unit)
1227            return self.func("DATE_TRUNC", expression.this, unit_sql, expression.args.get("zone"))
1228
1229        def mod_sql(self, expression: exp.Mod) -> str:
1230            this = expression.this
1231            expr = expression.expression
1232            return self.func(
1233                "MOD",
1234                this.unnest() if isinstance(this, exp.Paren) else this,
1235                expr.unnest() if isinstance(expr, exp.Paren) else expr,
1236            )
1237
1238        def column_parts(self, expression: exp.Column) -> str:
1239            if expression.meta.get("quoted_column"):
1240                # If a column reference is of the form `dataset.table`.name, we need
1241                # to preserve the quoted table path, otherwise the reference breaks
1242                table_parts = ".".join(p.name for p in expression.parts[:-1])
1243                table_path = self.sql(exp.Identifier(this=table_parts, quoted=True))
1244                return f"{table_path}.{self.sql(expression, 'this')}"
1245
1246            return super().column_parts(expression)
1247
1248        def table_parts(self, expression: exp.Table) -> str:
1249            # Depending on the context, `x.y` may not resolve to the same data source as `x`.`y`, so
1250            # we need to make sure the correct quoting is used in each case.
1251            #
1252            # For example, if there is a CTE x that clashes with a schema name, then the former will
1253            # return the table y in that schema, whereas the latter will return the CTE's y column:
1254            #
1255            # - WITH x AS (SELECT [1, 2] AS y) SELECT * FROM x, `x.y`   -> cross join
1256            # - WITH x AS (SELECT [1, 2] AS y) SELECT * FROM x, `x`.`y` -> implicit unnest
1257            if expression.meta.get("quoted_table"):
1258                table_parts = ".".join(p.name for p in expression.parts)
1259                return self.sql(exp.Identifier(this=table_parts, quoted=True))
1260
1261            return super().table_parts(expression)
1262
1263        def timetostr_sql(self, expression: exp.TimeToStr) -> str:
1264            this = expression.this
1265            if isinstance(this, exp.TsOrDsToDatetime):
1266                func_name = "FORMAT_DATETIME"
1267            elif isinstance(this, exp.TsOrDsToTimestamp):
1268                func_name = "FORMAT_TIMESTAMP"
1269            else:
1270                func_name = "FORMAT_DATE"
1271
1272            time_expr = (
1273                this
1274                if isinstance(this, (exp.TsOrDsToDatetime, exp.TsOrDsToTimestamp, exp.TsOrDsToDate))
1275                else expression
1276            )
1277            return self.func(
1278                func_name, self.format_time(expression), time_expr.this, expression.args.get("zone")
1279            )
1280
1281        def eq_sql(self, expression: exp.EQ) -> str:
1282            # Operands of = cannot be NULL in BigQuery
1283            if isinstance(expression.left, exp.Null) or isinstance(expression.right, exp.Null):
1284                if not isinstance(expression.parent, exp.Update):
1285                    return "NULL"
1286
1287            return self.binary(expression, "=")
1288
1289        def attimezone_sql(self, expression: exp.AtTimeZone) -> str:
1290            parent = expression.parent
1291
1292            # BigQuery allows CAST(.. AS {STRING|TIMESTAMP} [FORMAT <fmt> [AT TIME ZONE <tz>]]).
1293            # Only the TIMESTAMP one should use the below conversion, when AT TIME ZONE is included.
1294            if not isinstance(parent, exp.Cast) or not parent.to.is_type("text"):
1295                return self.func(
1296                    "TIMESTAMP", self.func("DATETIME", expression.this, expression.args.get("zone"))
1297                )
1298
1299            return super().attimezone_sql(expression)
1300
1301        def trycast_sql(self, expression: exp.TryCast) -> str:
1302            return self.cast_sql(expression, safe_prefix="SAFE_")
1303
1304        def bracket_sql(self, expression: exp.Bracket) -> str:
1305            this = expression.this
1306            expressions = expression.expressions
1307
1308            if len(expressions) == 1 and this and this.is_type(exp.DataType.Type.STRUCT):
1309                arg = expressions[0]
1310                if arg.type is None:
1311                    from sqlglot.optimizer.annotate_types import annotate_types
1312
1313                    arg = annotate_types(arg, dialect=self.dialect)
1314
1315                if arg.type and arg.type.this in exp.DataType.TEXT_TYPES:
1316                    # BQ doesn't support bracket syntax with string values for structs
1317                    return f"{self.sql(this)}.{arg.name}"
1318
1319            expressions_sql = self.expressions(expression, flat=True)
1320            offset = expression.args.get("offset")
1321
1322            if offset == 0:
1323                expressions_sql = f"OFFSET({expressions_sql})"
1324            elif offset == 1:
1325                expressions_sql = f"ORDINAL({expressions_sql})"
1326            elif offset is not None:
1327                self.unsupported(f"Unsupported array offset: {offset}")
1328
1329            if expression.args.get("safe"):
1330                expressions_sql = f"SAFE_{expressions_sql}"
1331
1332            return f"{self.sql(this)}[{expressions_sql}]"
1333
1334        def in_unnest_op(self, expression: exp.Unnest) -> str:
1335            return self.sql(expression)
1336
1337        def version_sql(self, expression: exp.Version) -> str:
1338            if expression.name == "TIMESTAMP":
1339                expression.set("this", "SYSTEM_TIME")
1340            return super().version_sql(expression)
1341
1342        def contains_sql(self, expression: exp.Contains) -> str:
1343            this = expression.this
1344            expr = expression.expression
1345
1346            if isinstance(this, exp.Lower) and isinstance(expr, exp.Lower):
1347                this = this.this
1348                expr = expr.this
1349
1350            return self.func("CONTAINS_SUBSTR", this, expr)
1351
1352        def cast_sql(self, expression: exp.Cast, safe_prefix: t.Optional[str] = None) -> str:
1353            this = expression.this
1354
1355            # This ensures that inline type-annotated ARRAY literals like ARRAY<INT64>[1, 2, 3]
1356            # are roundtripped unaffected. The inner check excludes ARRAY(SELECT ...) expressions,
1357            # because they aren't literals and so the above syntax is invalid BigQuery.
1358            if isinstance(this, exp.Array):
1359                elem = seq_get(this.expressions, 0)
1360                if not (elem and elem.find(exp.Query)):
1361                    return f"{self.sql(expression, 'to')}{self.sql(this)}"
1362
1363            return super().cast_sql(expression, safe_prefix=safe_prefix)