sqlglot.dialects.mysql

   1from __future__ import annotations
   2
   3import typing as t
   4
   5from sqlglot import exp, generator, parser, tokens, transforms
   6from sqlglot.dialects.dialect import (
   7    Dialect,
   8    NormalizationStrategy,
   9    arrow_json_extract_sql,
  10    date_add_interval_sql,
  11    datestrtodate_sql,
  12    build_formatted_time,
  13    isnull_to_is_null,
  14    length_or_char_length_sql,
  15    max_or_greatest,
  16    min_or_least,
  17    no_ilike_sql,
  18    no_paren_current_date_sql,
  19    no_pivot_sql,
  20    no_tablesample_sql,
  21    no_trycast_sql,
  22    build_date_delta,
  23    build_date_delta_with_interval,
  24    rename_func,
  25    strposition_sql,
  26    unit_to_var,
  27    trim_sql,
  28    timestrtotime_sql,
  29)
  30from sqlglot.generator import unsupported_args
  31from sqlglot.helper import seq_get
  32from sqlglot.tokens import TokenType
  33
  34
  35def _show_parser(*args: t.Any, **kwargs: t.Any) -> t.Callable[[MySQL.Parser], exp.Show]:
  36    def _parse(self: MySQL.Parser) -> exp.Show:
  37        return self._parse_show_mysql(*args, **kwargs)
  38
  39    return _parse
  40
  41
  42def _date_trunc_sql(self: MySQL.Generator, expression: exp.DateTrunc) -> str:
  43    expr = self.sql(expression, "this")
  44    unit = expression.text("unit").upper()
  45
  46    if unit == "WEEK":
  47        concat = f"CONCAT(YEAR({expr}), ' ', WEEK({expr}, 1), ' 1')"
  48        date_format = "%Y %u %w"
  49    elif unit == "MONTH":
  50        concat = f"CONCAT(YEAR({expr}), ' ', MONTH({expr}), ' 1')"
  51        date_format = "%Y %c %e"
  52    elif unit == "QUARTER":
  53        concat = f"CONCAT(YEAR({expr}), ' ', QUARTER({expr}) * 3 - 2, ' 1')"
  54        date_format = "%Y %c %e"
  55    elif unit == "YEAR":
  56        concat = f"CONCAT(YEAR({expr}), ' 1 1')"
  57        date_format = "%Y %c %e"
  58    else:
  59        if unit != "DAY":
  60            self.unsupported(f"Unexpected interval unit: {unit}")
  61        return self.func("DATE", expr)
  62
  63    return self.func("STR_TO_DATE", concat, f"'{date_format}'")
  64
  65
  66# All specifiers for time parts (as opposed to date parts)
  67# https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_date-format
  68TIME_SPECIFIERS = {"f", "H", "h", "I", "i", "k", "l", "p", "r", "S", "s", "T"}
  69
  70
  71def _has_time_specifier(date_format: str) -> bool:
  72    i = 0
  73    length = len(date_format)
  74
  75    while i < length:
  76        if date_format[i] == "%":
  77            i += 1
  78            if i < length and date_format[i] in TIME_SPECIFIERS:
  79                return True
  80        i += 1
  81    return False
  82
  83
  84def _str_to_date(args: t.List) -> exp.StrToDate | exp.StrToTime:
  85    mysql_date_format = seq_get(args, 1)
  86    date_format = MySQL.format_time(mysql_date_format)
  87    this = seq_get(args, 0)
  88
  89    if mysql_date_format and _has_time_specifier(mysql_date_format.name):
  90        return exp.StrToTime(this=this, format=date_format)
  91
  92    return exp.StrToDate(this=this, format=date_format)
  93
  94
  95def _str_to_date_sql(
  96    self: MySQL.Generator, expression: exp.StrToDate | exp.StrToTime | exp.TsOrDsToDate
  97) -> str:
  98    return self.func("STR_TO_DATE", expression.this, self.format_time(expression))
  99
 100
 101def _unix_to_time_sql(self: MySQL.Generator, expression: exp.UnixToTime) -> str:
 102    scale = expression.args.get("scale")
 103    timestamp = expression.this
 104
 105    if scale in (None, exp.UnixToTime.SECONDS):
 106        return self.func("FROM_UNIXTIME", timestamp, self.format_time(expression))
 107
 108    return self.func(
 109        "FROM_UNIXTIME",
 110        exp.Div(this=timestamp, expression=exp.func("POW", 10, scale)),
 111        self.format_time(expression),
 112    )
 113
 114
 115def date_add_sql(
 116    kind: str,
 117) -> t.Callable[[generator.Generator, exp.Expression], str]:
 118    def func(self: generator.Generator, expression: exp.Expression) -> str:
 119        return self.func(
 120            f"DATE_{kind}",
 121            expression.this,
 122            exp.Interval(this=expression.expression, unit=unit_to_var(expression)),
 123        )
 124
 125    return func
 126
 127
 128def _ts_or_ds_to_date_sql(self: MySQL.Generator, expression: exp.TsOrDsToDate) -> str:
 129    time_format = expression.args.get("format")
 130    return _str_to_date_sql(self, expression) if time_format else self.func("DATE", expression.this)
 131
 132
 133def _remove_ts_or_ds_to_date(
 134    to_sql: t.Optional[t.Callable[[MySQL.Generator, exp.Expression], str]] = None,
 135    args: t.Tuple[str, ...] = ("this",),
 136) -> t.Callable[[MySQL.Generator, exp.Func], str]:
 137    def func(self: MySQL.Generator, expression: exp.Func) -> str:
 138        for arg_key in args:
 139            arg = expression.args.get(arg_key)
 140            if isinstance(arg, exp.TsOrDsToDate) and not arg.args.get("format"):
 141                expression.set(arg_key, arg.this)
 142
 143        return to_sql(self, expression) if to_sql else self.function_fallback_sql(expression)
 144
 145    return func
 146
 147
 148class MySQL(Dialect):
 149    PROMOTE_TO_INFERRED_DATETIME_TYPE = True
 150
 151    # https://dev.mysql.com/doc/refman/8.0/en/identifiers.html
 152    IDENTIFIERS_CAN_START_WITH_DIGIT = True
 153
 154    # We default to treating all identifiers as case-sensitive, since it matches MySQL's
 155    # behavior on Linux systems. For MacOS and Windows systems, one can override this
 156    # setting by specifying `dialect="mysql, normalization_strategy = lowercase"`.
 157    #
 158    # See also https://dev.mysql.com/doc/refman/8.2/en/identifier-case-sensitivity.html
 159    NORMALIZATION_STRATEGY = NormalizationStrategy.CASE_SENSITIVE
 160
 161    TIME_FORMAT = "'%Y-%m-%d %T'"
 162    DPIPE_IS_STRING_CONCAT = False
 163    SUPPORTS_USER_DEFINED_TYPES = False
 164    SUPPORTS_SEMI_ANTI_JOIN = False
 165    SAFE_DIVISION = True
 166
 167    # https://prestodb.io/docs/current/functions/datetime.html#mysql-date-functions
 168    TIME_MAPPING = {
 169        "%M": "%B",
 170        "%c": "%-m",
 171        "%e": "%-d",
 172        "%h": "%I",
 173        "%i": "%M",
 174        "%s": "%S",
 175        "%u": "%W",
 176        "%k": "%-H",
 177        "%l": "%-I",
 178        "%T": "%H:%M:%S",
 179        "%W": "%A",
 180    }
 181
 182    class Tokenizer(tokens.Tokenizer):
 183        QUOTES = ["'", '"']
 184        COMMENTS = ["--", "#", ("/*", "*/")]
 185        IDENTIFIERS = ["`"]
 186        STRING_ESCAPES = ["'", '"', "\\"]
 187        BIT_STRINGS = [("b'", "'"), ("B'", "'"), ("0b", "")]
 188        HEX_STRINGS = [("x'", "'"), ("X'", "'"), ("0x", "")]
 189
 190        NESTED_COMMENTS = False
 191
 192        KEYWORDS = {
 193            **tokens.Tokenizer.KEYWORDS,
 194            "CHARSET": TokenType.CHARACTER_SET,
 195            # The DESCRIBE and EXPLAIN statements are synonyms.
 196            # https://dev.mysql.com/doc/refman/8.4/en/explain.html
 197            "BLOB": TokenType.BLOB,
 198            "EXPLAIN": TokenType.DESCRIBE,
 199            "FORCE": TokenType.FORCE,
 200            "IGNORE": TokenType.IGNORE,
 201            "KEY": TokenType.KEY,
 202            "LOCK TABLES": TokenType.COMMAND,
 203            "LONGBLOB": TokenType.LONGBLOB,
 204            "LONGTEXT": TokenType.LONGTEXT,
 205            "MEDIUMBLOB": TokenType.MEDIUMBLOB,
 206            "TINYBLOB": TokenType.TINYBLOB,
 207            "TINYTEXT": TokenType.TINYTEXT,
 208            "MEDIUMTEXT": TokenType.MEDIUMTEXT,
 209            "MEDIUMINT": TokenType.MEDIUMINT,
 210            "MEMBER OF": TokenType.MEMBER_OF,
 211            "SEPARATOR": TokenType.SEPARATOR,
 212            "SERIAL": TokenType.SERIAL,
 213            "START": TokenType.BEGIN,
 214            "SIGNED": TokenType.BIGINT,
 215            "SIGNED INTEGER": TokenType.BIGINT,
 216            "TIMESTAMP": TokenType.TIMESTAMPTZ,
 217            "UNLOCK TABLES": TokenType.COMMAND,
 218            "UNSIGNED": TokenType.UBIGINT,
 219            "UNSIGNED INTEGER": TokenType.UBIGINT,
 220            "YEAR": TokenType.YEAR,
 221            "_ARMSCII8": TokenType.INTRODUCER,
 222            "_ASCII": TokenType.INTRODUCER,
 223            "_BIG5": TokenType.INTRODUCER,
 224            "_BINARY": TokenType.INTRODUCER,
 225            "_CP1250": TokenType.INTRODUCER,
 226            "_CP1251": TokenType.INTRODUCER,
 227            "_CP1256": TokenType.INTRODUCER,
 228            "_CP1257": TokenType.INTRODUCER,
 229            "_CP850": TokenType.INTRODUCER,
 230            "_CP852": TokenType.INTRODUCER,
 231            "_CP866": TokenType.INTRODUCER,
 232            "_CP932": TokenType.INTRODUCER,
 233            "_DEC8": TokenType.INTRODUCER,
 234            "_EUCJPMS": TokenType.INTRODUCER,
 235            "_EUCKR": TokenType.INTRODUCER,
 236            "_GB18030": TokenType.INTRODUCER,
 237            "_GB2312": TokenType.INTRODUCER,
 238            "_GBK": TokenType.INTRODUCER,
 239            "_GEOSTD8": TokenType.INTRODUCER,
 240            "_GREEK": TokenType.INTRODUCER,
 241            "_HEBREW": TokenType.INTRODUCER,
 242            "_HP8": TokenType.INTRODUCER,
 243            "_KEYBCS2": TokenType.INTRODUCER,
 244            "_KOI8R": TokenType.INTRODUCER,
 245            "_KOI8U": TokenType.INTRODUCER,
 246            "_LATIN1": TokenType.INTRODUCER,
 247            "_LATIN2": TokenType.INTRODUCER,
 248            "_LATIN5": TokenType.INTRODUCER,
 249            "_LATIN7": TokenType.INTRODUCER,
 250            "_MACCE": TokenType.INTRODUCER,
 251            "_MACROMAN": TokenType.INTRODUCER,
 252            "_SJIS": TokenType.INTRODUCER,
 253            "_SWE7": TokenType.INTRODUCER,
 254            "_TIS620": TokenType.INTRODUCER,
 255            "_UCS2": TokenType.INTRODUCER,
 256            "_UJIS": TokenType.INTRODUCER,
 257            # https://dev.mysql.com/doc/refman/8.0/en/string-literals.html
 258            "_UTF8": TokenType.INTRODUCER,
 259            "_UTF16": TokenType.INTRODUCER,
 260            "_UTF16LE": TokenType.INTRODUCER,
 261            "_UTF32": TokenType.INTRODUCER,
 262            "_UTF8MB3": TokenType.INTRODUCER,
 263            "_UTF8MB4": TokenType.INTRODUCER,
 264            "@@": TokenType.SESSION_PARAMETER,
 265        }
 266
 267        COMMANDS = {*tokens.Tokenizer.COMMANDS, TokenType.REPLACE} - {TokenType.SHOW}
 268
 269    class Parser(parser.Parser):
 270        FUNC_TOKENS = {
 271            *parser.Parser.FUNC_TOKENS,
 272            TokenType.DATABASE,
 273            TokenType.SCHEMA,
 274            TokenType.VALUES,
 275        }
 276
 277        CONJUNCTION = {
 278            **parser.Parser.CONJUNCTION,
 279            TokenType.DAMP: exp.And,
 280            TokenType.XOR: exp.Xor,
 281        }
 282
 283        DISJUNCTION = {
 284            **parser.Parser.DISJUNCTION,
 285            TokenType.DPIPE: exp.Or,
 286        }
 287
 288        TABLE_ALIAS_TOKENS = (
 289            parser.Parser.TABLE_ALIAS_TOKENS - parser.Parser.TABLE_INDEX_HINT_TOKENS
 290        )
 291
 292        RANGE_PARSERS = {
 293            **parser.Parser.RANGE_PARSERS,
 294            TokenType.MEMBER_OF: lambda self, this: self.expression(
 295                exp.JSONArrayContains,
 296                this=this,
 297                expression=self._parse_wrapped(self._parse_expression),
 298            ),
 299        }
 300
 301        FUNCTIONS = {
 302            **parser.Parser.FUNCTIONS,
 303            "CONVERT_TZ": lambda args: exp.ConvertTimezone(
 304                source_tz=seq_get(args, 1), target_tz=seq_get(args, 2), timestamp=seq_get(args, 0)
 305            ),
 306            "CURDATE": exp.CurrentDate.from_arg_list,
 307            "DATE": lambda args: exp.TsOrDsToDate(this=seq_get(args, 0)),
 308            "DATE_ADD": build_date_delta_with_interval(exp.DateAdd),
 309            "DATE_FORMAT": build_formatted_time(exp.TimeToStr, "mysql"),
 310            "DATE_SUB": build_date_delta_with_interval(exp.DateSub),
 311            "DAY": lambda args: exp.Day(this=exp.TsOrDsToDate(this=seq_get(args, 0))),
 312            "DAYOFMONTH": lambda args: exp.DayOfMonth(this=exp.TsOrDsToDate(this=seq_get(args, 0))),
 313            "DAYOFWEEK": lambda args: exp.DayOfWeek(this=exp.TsOrDsToDate(this=seq_get(args, 0))),
 314            "DAYOFYEAR": lambda args: exp.DayOfYear(this=exp.TsOrDsToDate(this=seq_get(args, 0))),
 315            "FORMAT": exp.NumberToStr.from_arg_list,
 316            "FROM_UNIXTIME": build_formatted_time(exp.UnixToTime, "mysql"),
 317            "ISNULL": isnull_to_is_null,
 318            "LENGTH": lambda args: exp.Length(this=seq_get(args, 0), binary=True),
 319            "MAKETIME": exp.TimeFromParts.from_arg_list,
 320            "MONTH": lambda args: exp.Month(this=exp.TsOrDsToDate(this=seq_get(args, 0))),
 321            "MONTHNAME": lambda args: exp.TimeToStr(
 322                this=exp.TsOrDsToDate(this=seq_get(args, 0)),
 323                format=exp.Literal.string("%B"),
 324            ),
 325            "SCHEMA": exp.CurrentSchema.from_arg_list,
 326            "DATABASE": exp.CurrentSchema.from_arg_list,
 327            "STR_TO_DATE": _str_to_date,
 328            "TIMESTAMPDIFF": build_date_delta(exp.TimestampDiff),
 329            "TO_DAYS": lambda args: exp.paren(
 330                exp.DateDiff(
 331                    this=exp.TsOrDsToDate(this=seq_get(args, 0)),
 332                    expression=exp.TsOrDsToDate(this=exp.Literal.string("0000-01-01")),
 333                    unit=exp.var("DAY"),
 334                )
 335                + 1
 336            ),
 337            "WEEK": lambda args: exp.Week(
 338                this=exp.TsOrDsToDate(this=seq_get(args, 0)), mode=seq_get(args, 1)
 339            ),
 340            "WEEKOFYEAR": lambda args: exp.WeekOfYear(this=exp.TsOrDsToDate(this=seq_get(args, 0))),
 341            "YEAR": lambda args: exp.Year(this=exp.TsOrDsToDate(this=seq_get(args, 0))),
 342        }
 343
 344        FUNCTION_PARSERS = {
 345            **parser.Parser.FUNCTION_PARSERS,
 346            "CHAR": lambda self: self.expression(
 347                exp.Chr,
 348                expressions=self._parse_csv(self._parse_assignment),
 349                charset=self._match(TokenType.USING) and self._parse_var(),
 350            ),
 351            "GROUP_CONCAT": lambda self: self._parse_group_concat(),
 352            # https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values
 353            "VALUES": lambda self: self.expression(
 354                exp.Anonymous, this="VALUES", expressions=[self._parse_id_var()]
 355            ),
 356            "JSON_VALUE": lambda self: self._parse_json_value(),
 357        }
 358
 359        STATEMENT_PARSERS = {
 360            **parser.Parser.STATEMENT_PARSERS,
 361            TokenType.SHOW: lambda self: self._parse_show(),
 362        }
 363
 364        SHOW_PARSERS = {
 365            "BINARY LOGS": _show_parser("BINARY LOGS"),
 366            "MASTER LOGS": _show_parser("BINARY LOGS"),
 367            "BINLOG EVENTS": _show_parser("BINLOG EVENTS"),
 368            "CHARACTER SET": _show_parser("CHARACTER SET"),
 369            "CHARSET": _show_parser("CHARACTER SET"),
 370            "COLLATION": _show_parser("COLLATION"),
 371            "FULL COLUMNS": _show_parser("COLUMNS", target="FROM", full=True),
 372            "COLUMNS": _show_parser("COLUMNS", target="FROM"),
 373            "CREATE DATABASE": _show_parser("CREATE DATABASE", target=True),
 374            "CREATE EVENT": _show_parser("CREATE EVENT", target=True),
 375            "CREATE FUNCTION": _show_parser("CREATE FUNCTION", target=True),
 376            "CREATE PROCEDURE": _show_parser("CREATE PROCEDURE", target=True),
 377            "CREATE TABLE": _show_parser("CREATE TABLE", target=True),
 378            "CREATE TRIGGER": _show_parser("CREATE TRIGGER", target=True),
 379            "CREATE VIEW": _show_parser("CREATE VIEW", target=True),
 380            "DATABASES": _show_parser("DATABASES"),
 381            "SCHEMAS": _show_parser("DATABASES"),
 382            "ENGINE": _show_parser("ENGINE", target=True),
 383            "STORAGE ENGINES": _show_parser("ENGINES"),
 384            "ENGINES": _show_parser("ENGINES"),
 385            "ERRORS": _show_parser("ERRORS"),
 386            "EVENTS": _show_parser("EVENTS"),
 387            "FUNCTION CODE": _show_parser("FUNCTION CODE", target=True),
 388            "FUNCTION STATUS": _show_parser("FUNCTION STATUS"),
 389            "GRANTS": _show_parser("GRANTS", target="FOR"),
 390            "INDEX": _show_parser("INDEX", target="FROM"),
 391            "MASTER STATUS": _show_parser("MASTER STATUS"),
 392            "OPEN TABLES": _show_parser("OPEN TABLES"),
 393            "PLUGINS": _show_parser("PLUGINS"),
 394            "PROCEDURE CODE": _show_parser("PROCEDURE CODE", target=True),
 395            "PROCEDURE STATUS": _show_parser("PROCEDURE STATUS"),
 396            "PRIVILEGES": _show_parser("PRIVILEGES"),
 397            "FULL PROCESSLIST": _show_parser("PROCESSLIST", full=True),
 398            "PROCESSLIST": _show_parser("PROCESSLIST"),
 399            "PROFILE": _show_parser("PROFILE"),
 400            "PROFILES": _show_parser("PROFILES"),
 401            "RELAYLOG EVENTS": _show_parser("RELAYLOG EVENTS"),
 402            "REPLICAS": _show_parser("REPLICAS"),
 403            "SLAVE HOSTS": _show_parser("REPLICAS"),
 404            "REPLICA STATUS": _show_parser("REPLICA STATUS"),
 405            "SLAVE STATUS": _show_parser("REPLICA STATUS"),
 406            "GLOBAL STATUS": _show_parser("STATUS", global_=True),
 407            "SESSION STATUS": _show_parser("STATUS"),
 408            "STATUS": _show_parser("STATUS"),
 409            "TABLE STATUS": _show_parser("TABLE STATUS"),
 410            "FULL TABLES": _show_parser("TABLES", full=True),
 411            "TABLES": _show_parser("TABLES"),
 412            "TRIGGERS": _show_parser("TRIGGERS"),
 413            "GLOBAL VARIABLES": _show_parser("VARIABLES", global_=True),
 414            "SESSION VARIABLES": _show_parser("VARIABLES"),
 415            "VARIABLES": _show_parser("VARIABLES"),
 416            "WARNINGS": _show_parser("WARNINGS"),
 417        }
 418
 419        PROPERTY_PARSERS = {
 420            **parser.Parser.PROPERTY_PARSERS,
 421            "LOCK": lambda self: self._parse_property_assignment(exp.LockProperty),
 422        }
 423
 424        SET_PARSERS = {
 425            **parser.Parser.SET_PARSERS,
 426            "PERSIST": lambda self: self._parse_set_item_assignment("PERSIST"),
 427            "PERSIST_ONLY": lambda self: self._parse_set_item_assignment("PERSIST_ONLY"),
 428            "CHARACTER SET": lambda self: self._parse_set_item_charset("CHARACTER SET"),
 429            "CHARSET": lambda self: self._parse_set_item_charset("CHARACTER SET"),
 430            "NAMES": lambda self: self._parse_set_item_names(),
 431        }
 432
 433        CONSTRAINT_PARSERS = {
 434            **parser.Parser.CONSTRAINT_PARSERS,
 435            "FULLTEXT": lambda self: self._parse_index_constraint(kind="FULLTEXT"),
 436            "INDEX": lambda self: self._parse_index_constraint(),
 437            "KEY": lambda self: self._parse_index_constraint(),
 438            "SPATIAL": lambda self: self._parse_index_constraint(kind="SPATIAL"),
 439        }
 440
 441        ALTER_PARSERS = {
 442            **parser.Parser.ALTER_PARSERS,
 443            "MODIFY": lambda self: self._parse_alter_table_alter(),
 444        }
 445
 446        ALTER_ALTER_PARSERS = {
 447            **parser.Parser.ALTER_ALTER_PARSERS,
 448            "INDEX": lambda self: self._parse_alter_table_alter_index(),
 449        }
 450
 451        SCHEMA_UNNAMED_CONSTRAINTS = {
 452            *parser.Parser.SCHEMA_UNNAMED_CONSTRAINTS,
 453            "FULLTEXT",
 454            "INDEX",
 455            "KEY",
 456            "SPATIAL",
 457        }
 458
 459        PROFILE_TYPES: parser.OPTIONS_TYPE = {
 460            **dict.fromkeys(("ALL", "CPU", "IPC", "MEMORY", "SOURCE", "SWAPS"), tuple()),
 461            "BLOCK": ("IO",),
 462            "CONTEXT": ("SWITCHES",),
 463            "PAGE": ("FAULTS",),
 464        }
 465
 466        TYPE_TOKENS = {
 467            *parser.Parser.TYPE_TOKENS,
 468            TokenType.SET,
 469        }
 470
 471        ENUM_TYPE_TOKENS = {
 472            *parser.Parser.ENUM_TYPE_TOKENS,
 473            TokenType.SET,
 474        }
 475
 476        # SELECT [ ALL | DISTINCT | DISTINCTROW ] [ <OPERATION_MODIFIERS> ]
 477        OPERATION_MODIFIERS = {
 478            "HIGH_PRIORITY",
 479            "STRAIGHT_JOIN",
 480            "SQL_SMALL_RESULT",
 481            "SQL_BIG_RESULT",
 482            "SQL_BUFFER_RESULT",
 483            "SQL_NO_CACHE",
 484            "SQL_CALC_FOUND_ROWS",
 485        }
 486
 487        LOG_DEFAULTS_TO_LN = True
 488        STRING_ALIASES = True
 489        VALUES_FOLLOWED_BY_PAREN = False
 490        SUPPORTS_PARTITION_SELECTION = True
 491
 492        def _parse_generated_as_identity(
 493            self,
 494        ) -> (
 495            exp.GeneratedAsIdentityColumnConstraint
 496            | exp.ComputedColumnConstraint
 497            | exp.GeneratedAsRowColumnConstraint
 498        ):
 499            this = super()._parse_generated_as_identity()
 500
 501            if self._match_texts(("STORED", "VIRTUAL")):
 502                persisted = self._prev.text.upper() == "STORED"
 503
 504                if isinstance(this, exp.ComputedColumnConstraint):
 505                    this.set("persisted", persisted)
 506                elif isinstance(this, exp.GeneratedAsIdentityColumnConstraint):
 507                    this = self.expression(
 508                        exp.ComputedColumnConstraint, this=this.expression, persisted=persisted
 509                    )
 510
 511            return this
 512
 513        def _parse_primary_key_part(self) -> t.Optional[exp.Expression]:
 514            this = self._parse_id_var()
 515            if not self._match(TokenType.L_PAREN):
 516                return this
 517
 518            expression = self._parse_number()
 519            self._match_r_paren()
 520            return self.expression(exp.ColumnPrefix, this=this, expression=expression)
 521
 522        def _parse_index_constraint(
 523            self, kind: t.Optional[str] = None
 524        ) -> exp.IndexColumnConstraint:
 525            if kind:
 526                self._match_texts(("INDEX", "KEY"))
 527
 528            this = self._parse_id_var(any_token=False)
 529            index_type = self._match(TokenType.USING) and self._advance_any() and self._prev.text
 530            expressions = self._parse_wrapped_csv(self._parse_ordered)
 531
 532            options = []
 533            while True:
 534                if self._match_text_seq("KEY_BLOCK_SIZE"):
 535                    self._match(TokenType.EQ)
 536                    opt = exp.IndexConstraintOption(key_block_size=self._parse_number())
 537                elif self._match(TokenType.USING):
 538                    opt = exp.IndexConstraintOption(using=self._advance_any() and self._prev.text)
 539                elif self._match_text_seq("WITH", "PARSER"):
 540                    opt = exp.IndexConstraintOption(parser=self._parse_var(any_token=True))
 541                elif self._match(TokenType.COMMENT):
 542                    opt = exp.IndexConstraintOption(comment=self._parse_string())
 543                elif self._match_text_seq("VISIBLE"):
 544                    opt = exp.IndexConstraintOption(visible=True)
 545                elif self._match_text_seq("INVISIBLE"):
 546                    opt = exp.IndexConstraintOption(visible=False)
 547                elif self._match_text_seq("ENGINE_ATTRIBUTE"):
 548                    self._match(TokenType.EQ)
 549                    opt = exp.IndexConstraintOption(engine_attr=self._parse_string())
 550                elif self._match_text_seq("SECONDARY_ENGINE_ATTRIBUTE"):
 551                    self._match(TokenType.EQ)
 552                    opt = exp.IndexConstraintOption(secondary_engine_attr=self._parse_string())
 553                else:
 554                    opt = None
 555
 556                if not opt:
 557                    break
 558
 559                options.append(opt)
 560
 561            return self.expression(
 562                exp.IndexColumnConstraint,
 563                this=this,
 564                expressions=expressions,
 565                kind=kind,
 566                index_type=index_type,
 567                options=options,
 568            )
 569
 570        def _parse_show_mysql(
 571            self,
 572            this: str,
 573            target: bool | str = False,
 574            full: t.Optional[bool] = None,
 575            global_: t.Optional[bool] = None,
 576        ) -> exp.Show:
 577            if target:
 578                if isinstance(target, str):
 579                    self._match_text_seq(target)
 580                target_id = self._parse_id_var()
 581            else:
 582                target_id = None
 583
 584            log = self._parse_string() if self._match_text_seq("IN") else None
 585
 586            if this in ("BINLOG EVENTS", "RELAYLOG EVENTS"):
 587                position = self._parse_number() if self._match_text_seq("FROM") else None
 588                db = None
 589            else:
 590                position = None
 591                db = None
 592
 593                if self._match(TokenType.FROM):
 594                    db = self._parse_id_var()
 595                elif self._match(TokenType.DOT):
 596                    db = target_id
 597                    target_id = self._parse_id_var()
 598
 599            channel = self._parse_id_var() if self._match_text_seq("FOR", "CHANNEL") else None
 600
 601            like = self._parse_string() if self._match_text_seq("LIKE") else None
 602            where = self._parse_where()
 603
 604            if this == "PROFILE":
 605                types = self._parse_csv(lambda: self._parse_var_from_options(self.PROFILE_TYPES))
 606                query = self._parse_number() if self._match_text_seq("FOR", "QUERY") else None
 607                offset = self._parse_number() if self._match_text_seq("OFFSET") else None
 608                limit = self._parse_number() if self._match_text_seq("LIMIT") else None
 609            else:
 610                types, query = None, None
 611                offset, limit = self._parse_oldstyle_limit()
 612
 613            mutex = True if self._match_text_seq("MUTEX") else None
 614            mutex = False if self._match_text_seq("STATUS") else mutex
 615
 616            return self.expression(
 617                exp.Show,
 618                this=this,
 619                target=target_id,
 620                full=full,
 621                log=log,
 622                position=position,
 623                db=db,
 624                channel=channel,
 625                like=like,
 626                where=where,
 627                types=types,
 628                query=query,
 629                offset=offset,
 630                limit=limit,
 631                mutex=mutex,
 632                **{"global": global_},  # type: ignore
 633            )
 634
 635        def _parse_oldstyle_limit(
 636            self,
 637        ) -> t.Tuple[t.Optional[exp.Expression], t.Optional[exp.Expression]]:
 638            limit = None
 639            offset = None
 640            if self._match_text_seq("LIMIT"):
 641                parts = self._parse_csv(self._parse_number)
 642                if len(parts) == 1:
 643                    limit = parts[0]
 644                elif len(parts) == 2:
 645                    limit = parts[1]
 646                    offset = parts[0]
 647
 648            return offset, limit
 649
 650        def _parse_set_item_charset(self, kind: str) -> exp.Expression:
 651            this = self._parse_string() or self._parse_unquoted_field()
 652            return self.expression(exp.SetItem, this=this, kind=kind)
 653
 654        def _parse_set_item_names(self) -> exp.Expression:
 655            charset = self._parse_string() or self._parse_unquoted_field()
 656            if self._match_text_seq("COLLATE"):
 657                collate = self._parse_string() or self._parse_unquoted_field()
 658            else:
 659                collate = None
 660
 661            return self.expression(exp.SetItem, this=charset, collate=collate, kind="NAMES")
 662
 663        def _parse_type(
 664            self, parse_interval: bool = True, fallback_to_identifier: bool = False
 665        ) -> t.Optional[exp.Expression]:
 666            # mysql binary is special and can work anywhere, even in order by operations
 667            # it operates like a no paren func
 668            if self._match(TokenType.BINARY, advance=False):
 669                data_type = self._parse_types(check_func=True, allow_identifiers=False)
 670
 671                if isinstance(data_type, exp.DataType):
 672                    return self.expression(exp.Cast, this=self._parse_column(), to=data_type)
 673
 674            return super()._parse_type(
 675                parse_interval=parse_interval, fallback_to_identifier=fallback_to_identifier
 676            )
 677
 678        def _parse_group_concat(self) -> t.Optional[exp.Expression]:
 679            def concat_exprs(
 680                node: t.Optional[exp.Expression], exprs: t.List[exp.Expression]
 681            ) -> exp.Expression:
 682                if isinstance(node, exp.Distinct) and len(node.expressions) > 1:
 683                    concat_exprs = [
 684                        self.expression(exp.Concat, expressions=node.expressions, safe=True)
 685                    ]
 686                    node.set("expressions", concat_exprs)
 687                    return node
 688                if len(exprs) == 1:
 689                    return exprs[0]
 690                return self.expression(exp.Concat, expressions=args, safe=True)
 691
 692            args = self._parse_csv(self._parse_lambda)
 693
 694            if args:
 695                order = args[-1] if isinstance(args[-1], exp.Order) else None
 696
 697                if order:
 698                    # Order By is the last (or only) expression in the list and has consumed the 'expr' before it,
 699                    # remove 'expr' from exp.Order and add it back to args
 700                    args[-1] = order.this
 701                    order.set("this", concat_exprs(order.this, args))
 702
 703                this = order or concat_exprs(args[0], args)
 704            else:
 705                this = None
 706
 707            separator = self._parse_field() if self._match(TokenType.SEPARATOR) else None
 708
 709            return self.expression(exp.GroupConcat, this=this, separator=separator)
 710
 711        def _parse_json_value(self) -> exp.JSONValue:
 712            this = self._parse_bitwise()
 713            self._match(TokenType.COMMA)
 714            path = self._parse_bitwise()
 715
 716            returning = self._match(TokenType.RETURNING) and self._parse_type()
 717
 718            return self.expression(
 719                exp.JSONValue,
 720                this=this,
 721                path=self.dialect.to_json_path(path),
 722                returning=returning,
 723                on_condition=self._parse_on_condition(),
 724            )
 725
 726        def _parse_alter_table_alter_index(self) -> exp.AlterIndex:
 727            index = self._parse_field(any_token=True)
 728
 729            if self._match_text_seq("VISIBLE"):
 730                visible = True
 731            elif self._match_text_seq("INVISIBLE"):
 732                visible = False
 733            else:
 734                visible = None
 735
 736            return self.expression(exp.AlterIndex, this=index, visible=visible)
 737
 738    class Generator(generator.Generator):
 739        INTERVAL_ALLOWS_PLURAL_FORM = False
 740        LOCKING_READS_SUPPORTED = True
 741        NULL_ORDERING_SUPPORTED = None
 742        JOIN_HINTS = False
 743        TABLE_HINTS = True
 744        DUPLICATE_KEY_UPDATE_WITH_SET = False
 745        QUERY_HINT_SEP = " "
 746        VALUES_AS_TABLE = False
 747        NVL2_SUPPORTED = False
 748        LAST_DAY_SUPPORTS_DATE_PART = False
 749        JSON_TYPE_REQUIRED_FOR_EXTRACTION = True
 750        JSON_PATH_BRACKETED_KEY_SUPPORTED = False
 751        JSON_KEY_VALUE_PAIR_SEP = ","
 752        SUPPORTS_TO_NUMBER = False
 753        PARSE_JSON_NAME: t.Optional[str] = None
 754        PAD_FILL_PATTERN_IS_REQUIRED = True
 755        WRAP_DERIVED_VALUES = False
 756        VARCHAR_REQUIRES_SIZE = True
 757        SUPPORTS_MEDIAN = False
 758
 759        TRANSFORMS = {
 760            **generator.Generator.TRANSFORMS,
 761            exp.ArrayAgg: rename_func("GROUP_CONCAT"),
 762            exp.CurrentDate: no_paren_current_date_sql,
 763            exp.DateDiff: _remove_ts_or_ds_to_date(
 764                lambda self, e: self.func("DATEDIFF", e.this, e.expression), ("this", "expression")
 765            ),
 766            exp.DateAdd: _remove_ts_or_ds_to_date(date_add_sql("ADD")),
 767            exp.DateStrToDate: datestrtodate_sql,
 768            exp.DateSub: _remove_ts_or_ds_to_date(date_add_sql("SUB")),
 769            exp.DateTrunc: _date_trunc_sql,
 770            exp.Day: _remove_ts_or_ds_to_date(),
 771            exp.DayOfMonth: _remove_ts_or_ds_to_date(rename_func("DAYOFMONTH")),
 772            exp.DayOfWeek: _remove_ts_or_ds_to_date(rename_func("DAYOFWEEK")),
 773            exp.DayOfYear: _remove_ts_or_ds_to_date(rename_func("DAYOFYEAR")),
 774            exp.GroupConcat: lambda self,
 775            e: f"""GROUP_CONCAT({self.sql(e, "this")} SEPARATOR {self.sql(e, "separator") or "','"})""",
 776            exp.ILike: no_ilike_sql,
 777            exp.JSONExtractScalar: arrow_json_extract_sql,
 778            exp.Length: length_or_char_length_sql,
 779            exp.LogicalOr: rename_func("MAX"),
 780            exp.LogicalAnd: rename_func("MIN"),
 781            exp.Max: max_or_greatest,
 782            exp.Min: min_or_least,
 783            exp.Month: _remove_ts_or_ds_to_date(),
 784            exp.NullSafeEQ: lambda self, e: self.binary(e, "<=>"),
 785            exp.NullSafeNEQ: lambda self, e: f"NOT {self.binary(e, '<=>')}",
 786            exp.NumberToStr: rename_func("FORMAT"),
 787            exp.Pivot: no_pivot_sql,
 788            exp.Select: transforms.preprocess(
 789                [
 790                    transforms.eliminate_distinct_on,
 791                    transforms.eliminate_semi_and_anti_joins,
 792                    transforms.eliminate_qualify,
 793                    transforms.eliminate_full_outer_join,
 794                    transforms.unnest_generate_date_array_using_recursive_cte,
 795                ]
 796            ),
 797            exp.StrPosition: lambda self, e: strposition_sql(
 798                self, e, func_name="LOCATE", supports_position=True
 799            ),
 800            exp.StrToDate: _str_to_date_sql,
 801            exp.StrToTime: _str_to_date_sql,
 802            exp.Stuff: rename_func("INSERT"),
 803            exp.TableSample: no_tablesample_sql,
 804            exp.TimeFromParts: rename_func("MAKETIME"),
 805            exp.TimestampAdd: date_add_interval_sql("DATE", "ADD"),
 806            exp.TimestampDiff: lambda self, e: self.func(
 807                "TIMESTAMPDIFF", unit_to_var(e), e.expression, e.this
 808            ),
 809            exp.TimestampSub: date_add_interval_sql("DATE", "SUB"),
 810            exp.TimeStrToUnix: rename_func("UNIX_TIMESTAMP"),
 811            exp.TimeStrToTime: lambda self, e: timestrtotime_sql(
 812                self,
 813                e,
 814                include_precision=not e.args.get("zone"),
 815            ),
 816            exp.TimeToStr: _remove_ts_or_ds_to_date(
 817                lambda self, e: self.func("DATE_FORMAT", e.this, self.format_time(e))
 818            ),
 819            exp.Trim: trim_sql,
 820            exp.TryCast: no_trycast_sql,
 821            exp.TsOrDsAdd: date_add_sql("ADD"),
 822            exp.TsOrDsDiff: lambda self, e: self.func("DATEDIFF", e.this, e.expression),
 823            exp.TsOrDsToDate: _ts_or_ds_to_date_sql,
 824            exp.Unicode: lambda self, e: f"ORD(CONVERT({self.sql(e.this)} USING utf32))",
 825            exp.UnixToTime: _unix_to_time_sql,
 826            exp.Week: _remove_ts_or_ds_to_date(),
 827            exp.WeekOfYear: _remove_ts_or_ds_to_date(rename_func("WEEKOFYEAR")),
 828            exp.Year: _remove_ts_or_ds_to_date(),
 829        }
 830
 831        UNSIGNED_TYPE_MAPPING = {
 832            exp.DataType.Type.UBIGINT: "BIGINT",
 833            exp.DataType.Type.UINT: "INT",
 834            exp.DataType.Type.UMEDIUMINT: "MEDIUMINT",
 835            exp.DataType.Type.USMALLINT: "SMALLINT",
 836            exp.DataType.Type.UTINYINT: "TINYINT",
 837            exp.DataType.Type.UDECIMAL: "DECIMAL",
 838            exp.DataType.Type.UDOUBLE: "DOUBLE",
 839        }
 840
 841        TIMESTAMP_TYPE_MAPPING = {
 842            exp.DataType.Type.DATETIME2: "DATETIME",
 843            exp.DataType.Type.SMALLDATETIME: "DATETIME",
 844            exp.DataType.Type.TIMESTAMP: "DATETIME",
 845            exp.DataType.Type.TIMESTAMPNTZ: "DATETIME",
 846            exp.DataType.Type.TIMESTAMPTZ: "TIMESTAMP",
 847            exp.DataType.Type.TIMESTAMPLTZ: "TIMESTAMP",
 848        }
 849
 850        TYPE_MAPPING = {
 851            **generator.Generator.TYPE_MAPPING,
 852            **UNSIGNED_TYPE_MAPPING,
 853            **TIMESTAMP_TYPE_MAPPING,
 854        }
 855
 856        TYPE_MAPPING.pop(exp.DataType.Type.MEDIUMTEXT)
 857        TYPE_MAPPING.pop(exp.DataType.Type.LONGTEXT)
 858        TYPE_MAPPING.pop(exp.DataType.Type.TINYTEXT)
 859        TYPE_MAPPING.pop(exp.DataType.Type.BLOB)
 860        TYPE_MAPPING.pop(exp.DataType.Type.MEDIUMBLOB)
 861        TYPE_MAPPING.pop(exp.DataType.Type.LONGBLOB)
 862        TYPE_MAPPING.pop(exp.DataType.Type.TINYBLOB)
 863
 864        PROPERTIES_LOCATION = {
 865            **generator.Generator.PROPERTIES_LOCATION,
 866            exp.TransientProperty: exp.Properties.Location.UNSUPPORTED,
 867            exp.VolatileProperty: exp.Properties.Location.UNSUPPORTED,
 868        }
 869
 870        LIMIT_FETCH = "LIMIT"
 871
 872        LIMIT_ONLY_LITERALS = True
 873
 874        CHAR_CAST_MAPPING = dict.fromkeys(
 875            (
 876                exp.DataType.Type.LONGTEXT,
 877                exp.DataType.Type.LONGBLOB,
 878                exp.DataType.Type.MEDIUMBLOB,
 879                exp.DataType.Type.MEDIUMTEXT,
 880                exp.DataType.Type.TEXT,
 881                exp.DataType.Type.TINYBLOB,
 882                exp.DataType.Type.TINYTEXT,
 883                exp.DataType.Type.VARCHAR,
 884            ),
 885            "CHAR",
 886        )
 887        SIGNED_CAST_MAPPING = dict.fromkeys(
 888            (
 889                exp.DataType.Type.BIGINT,
 890                exp.DataType.Type.BOOLEAN,
 891                exp.DataType.Type.INT,
 892                exp.DataType.Type.SMALLINT,
 893                exp.DataType.Type.TINYINT,
 894                exp.DataType.Type.MEDIUMINT,
 895            ),
 896            "SIGNED",
 897        )
 898
 899        # MySQL doesn't support many datatypes in cast.
 900        # https://dev.mysql.com/doc/refman/8.0/en/cast-functions.html#function_cast
 901        CAST_MAPPING = {
 902            **CHAR_CAST_MAPPING,
 903            **SIGNED_CAST_MAPPING,
 904            exp.DataType.Type.UBIGINT: "UNSIGNED",
 905        }
 906
 907        TIMESTAMP_FUNC_TYPES = {
 908            exp.DataType.Type.TIMESTAMPTZ,
 909            exp.DataType.Type.TIMESTAMPLTZ,
 910        }
 911
 912        # https://dev.mysql.com/doc/refman/8.0/en/keywords.html
 913        RESERVED_KEYWORDS = {
 914            "accessible",
 915            "add",
 916            "all",
 917            "alter",
 918            "analyze",
 919            "and",
 920            "as",
 921            "asc",
 922            "asensitive",
 923            "before",
 924            "between",
 925            "bigint",
 926            "binary",
 927            "blob",
 928            "both",
 929            "by",
 930            "call",
 931            "cascade",
 932            "case",
 933            "change",
 934            "char",
 935            "character",
 936            "check",
 937            "collate",
 938            "column",
 939            "condition",
 940            "constraint",
 941            "continue",
 942            "convert",
 943            "create",
 944            "cross",
 945            "cube",
 946            "cume_dist",
 947            "current_date",
 948            "current_time",
 949            "current_timestamp",
 950            "current_user",
 951            "cursor",
 952            "database",
 953            "databases",
 954            "day_hour",
 955            "day_microsecond",
 956            "day_minute",
 957            "day_second",
 958            "dec",
 959            "decimal",
 960            "declare",
 961            "default",
 962            "delayed",
 963            "delete",
 964            "dense_rank",
 965            "desc",
 966            "describe",
 967            "deterministic",
 968            "distinct",
 969            "distinctrow",
 970            "div",
 971            "double",
 972            "drop",
 973            "dual",
 974            "each",
 975            "else",
 976            "elseif",
 977            "empty",
 978            "enclosed",
 979            "escaped",
 980            "except",
 981            "exists",
 982            "exit",
 983            "explain",
 984            "false",
 985            "fetch",
 986            "first_value",
 987            "float",
 988            "float4",
 989            "float8",
 990            "for",
 991            "force",
 992            "foreign",
 993            "from",
 994            "fulltext",
 995            "function",
 996            "generated",
 997            "get",
 998            "grant",
 999            "group",
1000            "grouping",
1001            "groups",
1002            "having",
1003            "high_priority",
1004            "hour_microsecond",
1005            "hour_minute",
1006            "hour_second",
1007            "if",
1008            "ignore",
1009            "in",
1010            "index",
1011            "infile",
1012            "inner",
1013            "inout",
1014            "insensitive",
1015            "insert",
1016            "int",
1017            "int1",
1018            "int2",
1019            "int3",
1020            "int4",
1021            "int8",
1022            "integer",
1023            "intersect",
1024            "interval",
1025            "into",
1026            "io_after_gtids",
1027            "io_before_gtids",
1028            "is",
1029            "iterate",
1030            "join",
1031            "json_table",
1032            "key",
1033            "keys",
1034            "kill",
1035            "lag",
1036            "last_value",
1037            "lateral",
1038            "lead",
1039            "leading",
1040            "leave",
1041            "left",
1042            "like",
1043            "limit",
1044            "linear",
1045            "lines",
1046            "load",
1047            "localtime",
1048            "localtimestamp",
1049            "lock",
1050            "long",
1051            "longblob",
1052            "longtext",
1053            "loop",
1054            "low_priority",
1055            "master_bind",
1056            "master_ssl_verify_server_cert",
1057            "match",
1058            "maxvalue",
1059            "mediumblob",
1060            "mediumint",
1061            "mediumtext",
1062            "middleint",
1063            "minute_microsecond",
1064            "minute_second",
1065            "mod",
1066            "modifies",
1067            "natural",
1068            "not",
1069            "no_write_to_binlog",
1070            "nth_value",
1071            "ntile",
1072            "null",
1073            "numeric",
1074            "of",
1075            "on",
1076            "optimize",
1077            "optimizer_costs",
1078            "option",
1079            "optionally",
1080            "or",
1081            "order",
1082            "out",
1083            "outer",
1084            "outfile",
1085            "over",
1086            "partition",
1087            "percent_rank",
1088            "precision",
1089            "primary",
1090            "procedure",
1091            "purge",
1092            "range",
1093            "rank",
1094            "read",
1095            "reads",
1096            "read_write",
1097            "real",
1098            "recursive",
1099            "references",
1100            "regexp",
1101            "release",
1102            "rename",
1103            "repeat",
1104            "replace",
1105            "require",
1106            "resignal",
1107            "restrict",
1108            "return",
1109            "revoke",
1110            "right",
1111            "rlike",
1112            "row",
1113            "rows",
1114            "row_number",
1115            "schema",
1116            "schemas",
1117            "second_microsecond",
1118            "select",
1119            "sensitive",
1120            "separator",
1121            "set",
1122            "show",
1123            "signal",
1124            "smallint",
1125            "spatial",
1126            "specific",
1127            "sql",
1128            "sqlexception",
1129            "sqlstate",
1130            "sqlwarning",
1131            "sql_big_result",
1132            "sql_calc_found_rows",
1133            "sql_small_result",
1134            "ssl",
1135            "starting",
1136            "stored",
1137            "straight_join",
1138            "system",
1139            "table",
1140            "terminated",
1141            "then",
1142            "tinyblob",
1143            "tinyint",
1144            "tinytext",
1145            "to",
1146            "trailing",
1147            "trigger",
1148            "true",
1149            "undo",
1150            "union",
1151            "unique",
1152            "unlock",
1153            "unsigned",
1154            "update",
1155            "usage",
1156            "use",
1157            "using",
1158            "utc_date",
1159            "utc_time",
1160            "utc_timestamp",
1161            "values",
1162            "varbinary",
1163            "varchar",
1164            "varcharacter",
1165            "varying",
1166            "virtual",
1167            "when",
1168            "where",
1169            "while",
1170            "window",
1171            "with",
1172            "write",
1173            "xor",
1174            "year_month",
1175            "zerofill",
1176        }
1177
1178        def computedcolumnconstraint_sql(self, expression: exp.ComputedColumnConstraint) -> str:
1179            persisted = "STORED" if expression.args.get("persisted") else "VIRTUAL"
1180            return f"GENERATED ALWAYS AS ({self.sql(expression.this.unnest())}) {persisted}"
1181
1182        def array_sql(self, expression: exp.Array) -> str:
1183            self.unsupported("Arrays are not supported by MySQL")
1184            return self.function_fallback_sql(expression)
1185
1186        def arraycontainsall_sql(self, expression: exp.ArrayContainsAll) -> str:
1187            self.unsupported("Array operations are not supported by MySQL")
1188            return self.function_fallback_sql(expression)
1189
1190        def dpipe_sql(self, expression: exp.DPipe) -> str:
1191            return self.func("CONCAT", *expression.flatten())
1192
1193        def extract_sql(self, expression: exp.Extract) -> str:
1194            unit = expression.name
1195            if unit and unit.lower() == "epoch":
1196                return self.func("UNIX_TIMESTAMP", expression.expression)
1197
1198            return super().extract_sql(expression)
1199
1200        def datatype_sql(self, expression: exp.DataType) -> str:
1201            if (
1202                self.VARCHAR_REQUIRES_SIZE
1203                and expression.is_type(exp.DataType.Type.VARCHAR)
1204                and not expression.expressions
1205            ):
1206                # `VARCHAR` must always have a size - if it doesn't, we always generate `TEXT`
1207                return "TEXT"
1208
1209            # https://dev.mysql.com/doc/refman/8.0/en/numeric-type-syntax.html
1210            result = super().datatype_sql(expression)
1211            if expression.this in self.UNSIGNED_TYPE_MAPPING:
1212                result = f"{result} UNSIGNED"
1213
1214            return result
1215
1216        def jsonarraycontains_sql(self, expression: exp.JSONArrayContains) -> str:
1217            return f"{self.sql(expression, 'this')} MEMBER OF({self.sql(expression, 'expression')})"
1218
1219        def cast_sql(self, expression: exp.Cast, safe_prefix: t.Optional[str] = None) -> str:
1220            if expression.to.this in self.TIMESTAMP_FUNC_TYPES:
1221                return self.func("TIMESTAMP", expression.this)
1222
1223            to = self.CAST_MAPPING.get(expression.to.this)
1224
1225            if to:
1226                expression.to.set("this", to)
1227            return super().cast_sql(expression)
1228
1229        def show_sql(self, expression: exp.Show) -> str:
1230            this = f" {expression.name}"
1231            full = " FULL" if expression.args.get("full") else ""
1232            global_ = " GLOBAL" if expression.args.get("global") else ""
1233
1234            target = self.sql(expression, "target")
1235            target = f" {target}" if target else ""
1236            if expression.name in ("COLUMNS", "INDEX"):
1237                target = f" FROM{target}"
1238            elif expression.name == "GRANTS":
1239                target = f" FOR{target}"
1240
1241            db = self._prefixed_sql("FROM", expression, "db")
1242
1243            like = self._prefixed_sql("LIKE", expression, "like")
1244            where = self.sql(expression, "where")
1245
1246            types = self.expressions(expression, key="types")
1247            types = f" {types}" if types else types
1248            query = self._prefixed_sql("FOR QUERY", expression, "query")
1249
1250            if expression.name == "PROFILE":
1251                offset = self._prefixed_sql("OFFSET", expression, "offset")
1252                limit = self._prefixed_sql("LIMIT", expression, "limit")
1253            else:
1254                offset = ""
1255                limit = self._oldstyle_limit_sql(expression)
1256
1257            log = self._prefixed_sql("IN", expression, "log")
1258            position = self._prefixed_sql("FROM", expression, "position")
1259
1260            channel = self._prefixed_sql("FOR CHANNEL", expression, "channel")
1261
1262            if expression.name == "ENGINE":
1263                mutex_or_status = " MUTEX" if expression.args.get("mutex") else " STATUS"
1264            else:
1265                mutex_or_status = ""
1266
1267            return f"SHOW{full}{global_}{this}{target}{types}{db}{query}{log}{position}{channel}{mutex_or_status}{like}{where}{offset}{limit}"
1268
1269        def altercolumn_sql(self, expression: exp.AlterColumn) -> str:
1270            dtype = self.sql(expression, "dtype")
1271            if not dtype:
1272                return super().altercolumn_sql(expression)
1273
1274            this = self.sql(expression, "this")
1275            return f"MODIFY COLUMN {this} {dtype}"
1276
1277        def _prefixed_sql(self, prefix: str, expression: exp.Expression, arg: str) -> str:
1278            sql = self.sql(expression, arg)
1279            return f" {prefix} {sql}" if sql else ""
1280
1281        def _oldstyle_limit_sql(self, expression: exp.Show) -> str:
1282            limit = self.sql(expression, "limit")
1283            offset = self.sql(expression, "offset")
1284            if limit:
1285                limit_offset = f"{offset}, {limit}" if offset else limit
1286                return f" LIMIT {limit_offset}"
1287            return ""
1288
1289        def chr_sql(self, expression: exp.Chr) -> str:
1290            this = self.expressions(sqls=[expression.this] + expression.expressions)
1291            charset = expression.args.get("charset")
1292            using = f" USING {self.sql(charset)}" if charset else ""
1293            return f"CHAR({this}{using})"
1294
1295        def timestamptrunc_sql(self, expression: exp.TimestampTrunc) -> str:
1296            unit = expression.args.get("unit")
1297
1298            # Pick an old-enough date to avoid negative timestamp diffs
1299            start_ts = "'0000-01-01 00:00:00'"
1300
1301            # Source: https://stackoverflow.com/a/32955740
1302            timestamp_diff = build_date_delta(exp.TimestampDiff)([unit, start_ts, expression.this])
1303            interval = exp.Interval(this=timestamp_diff, unit=unit)
1304            dateadd = build_date_delta_with_interval(exp.DateAdd)([start_ts, interval])
1305
1306            return self.sql(dateadd)
1307
1308        def converttimezone_sql(self, expression: exp.ConvertTimezone) -> str:
1309            from_tz = expression.args.get("source_tz")
1310            to_tz = expression.args.get("target_tz")
1311            dt = expression.args.get("timestamp")
1312
1313            return self.func("CONVERT_TZ", dt, from_tz, to_tz)
1314
1315        def attimezone_sql(self, expression: exp.AtTimeZone) -> str:
1316            self.unsupported("AT TIME ZONE is not supported by MySQL")
1317            return self.sql(expression.this)
1318
1319        def isascii_sql(self, expression: exp.IsAscii) -> str:
1320            return f"REGEXP_LIKE({self.sql(expression.this)}, '^[[:ascii:]]*$')"
1321
1322        @unsupported_args("this")
1323        def currentschema_sql(self, expression: exp.CurrentSchema) -> str:
1324            return self.func("SCHEMA")