sqlglot.generators.tsql

  1from __future__ import annotations
  2
  3from functools import reduce
  4
  5from sqlglot import exp, generator, transforms
  6from sqlglot.dialects.dialect import (
  7    any_value_to_max_sql,
  8    date_delta_sql,
  9    datestrtodate_sql,
 10    generatedasidentitycolumnconstraint_sql,
 11    max_or_greatest,
 12    min_or_least,
 13    remove_ts_or_ds_to_date,
 14    rename_func,
 15    strposition_sql,
 16    timestrtotime_sql,
 17    trim_sql,
 18)
 19from sqlglot.helper import seq_get
 20from sqlglot.optimizer.scope import find_in_scope
 21from sqlglot.parsers.tsql import OPTIONS_THAT_REQUIRE_EQUAL
 22from sqlglot.time import format_time
 23from collections import defaultdict
 24
 25DATE_PART_UNMAPPING = {
 26    "WEEKISO": "ISO_WEEK",
 27    "DAYOFWEEK": "WEEKDAY",
 28    "TIMEZONE_MINUTE": "TZOFFSET",
 29}
 30
 31BIT_TYPES = {exp.EQ, exp.NEQ, exp.Is, exp.In, exp.Select, exp.Alias}
 32
 33
 34def _format_sql(self: TSQLGenerator, expression: exp.NumberToStr | exp.TimeToStr) -> str:
 35    fmt = expression.args["format"]
 36
 37    if not isinstance(expression, exp.NumberToStr):
 38        if fmt.is_string:
 39            from sqlglot.dialects.tsql import TSQL
 40
 41            mapped_fmt = format_time(fmt.name, TSQL.INVERSE_TIME_MAPPING)
 42            fmt_sql = self.sql(exp.Literal.string(mapped_fmt))
 43        else:
 44            fmt_sql = self.format_time(expression) or self.sql(fmt)
 45    else:
 46        fmt_sql = self.sql(fmt)
 47
 48    return self.func("FORMAT", expression.this, fmt_sql, expression.args.get("culture"))
 49
 50
 51def _string_agg_sql(self: TSQLGenerator, expression: exp.GroupConcat) -> str:
 52    this = expression.this
 53    distinct = find_in_scope(expression, exp.Distinct)
 54    if distinct:
 55        # exp.Distinct can appear below an exp.Order or an exp.GroupConcat expression
 56        self.unsupported("T-SQL STRING_AGG doesn't support DISTINCT.")
 57        this = distinct.pop().expressions[0]
 58
 59    order = ""
 60    if isinstance(expression.this, exp.Order):
 61        if expression.this.this:
 62            this = expression.this.this.pop()
 63        # Order has a leading space
 64        order = f" WITHIN GROUP ({self.sql(expression.this)[1:]})"
 65
 66    separator = expression.args.get("separator") or exp.Literal.string(",")
 67    return f"STRING_AGG({self.format_args(this, separator)}){order}"
 68
 69
 70def qualify_derived_table_outputs(expression: exp.Expr) -> exp.Expr:
 71    """Ensures all (unnamed) output columns are aliased for CTEs and Subqueries."""
 72    alias = expression.args.get("alias")
 73
 74    if (
 75        isinstance(expression, (exp.CTE, exp.Subquery))
 76        and isinstance(alias, exp.TableAlias)
 77        and not alias.columns
 78    ):
 79        from sqlglot.dialects.tsql import TSQL
 80        from sqlglot.optimizer.qualify_columns import qualify_outputs
 81
 82        # We keep track of the unaliased column projection indexes instead of the expressions
 83        # themselves, because the latter are going to be replaced by new nodes when the aliases
 84        # are added and hence we won't be able to reach these newly added Alias parents
 85        query = expression.this
 86        unaliased_column_indexes = (
 87            i for i, c in enumerate(query.selects) if isinstance(c, exp.Column) and not c.alias
 88        )
 89
 90        qualify_outputs(query, dialect=TSQL())
 91
 92        # Preserve the quoting information of columns for newly added Alias nodes
 93        query_selects = query.selects
 94        for select_index in unaliased_column_indexes:
 95            alias = query_selects[select_index]
 96            column = alias.this
 97            if isinstance(column.this, exp.Identifier):
 98                alias.args["alias"].set("quoted", column.this.quoted)
 99
100    return expression
101
102
103def _json_extract_sql(
104    self: TSQLGenerator, expression: exp.JSONExtract | exp.JSONExtractScalar
105) -> str:
106    # JSON_QUERY returns objects and arrays, JSON_VALUE returns scalars. A scalar-only
107    # extraction maps to JSON_VALUE; a source that also returns non-scalar values as
108    # text (e.g. SQLite's ->>) needs to try both, like a generic JSONExtract does
109    if isinstance(expression, exp.JSONExtractScalar) and expression.args.get("scalar_only"):
110        return self.func("JSON_VALUE", expression.this, expression.expression)
111
112    json_query = self.func("JSON_QUERY", expression.this, expression.expression)
113    if expression.args.get("json_query"):
114        return json_query
115
116    json_value = self.func("JSON_VALUE", expression.this, expression.expression)
117    return self.func("ISNULL", json_query, json_value)
118
119
120def _timestrtotime_sql(self: TSQLGenerator, expression: exp.TimeStrToTime):
121    sql = timestrtotime_sql(self, expression)
122    if expression.args.get("zone"):
123        # If there is a timezone, produce an expression like:
124        # CAST('2020-01-01 12:13:14-08:00' AS DATETIMEOFFSET) AT TIME ZONE 'UTC'
125        # If you dont have AT TIME ZONE 'UTC', wrapping that expression in another cast back to DATETIME2 just drops the timezone information
126        return self.sql(exp.AtTimeZone(this=sql, zone=exp.Literal.string("UTC")))
127    return sql
128
129
130class TSQLGenerator(generator.Generator):
131    SELECT_KINDS: tuple[str, ...] = ()
132    TRY_SUPPORTED = False
133    SUPPORTS_UESCAPE = False
134    SUPPORTS_DECODE_CASE = False
135
136    AFTER_HAVING_MODIFIER_TRANSFORMS = generator.AFTER_HAVING_MODIFIER_TRANSFORMS
137
138    LIMIT_IS_TOP = True
139    QUERY_HINTS = False
140    RETURNING_END = False
141    NVL2_SUPPORTED = False
142    ALTER_TABLE_INCLUDE_COLUMN_KEYWORD = False
143    LIMIT_FETCH = "FETCH"
144    COMPUTED_COLUMN_WITH_TYPE = False
145    CTE_RECURSIVE_KEYWORD_REQUIRED = False
146    ENSURE_BOOLS = True
147    NULL_ORDERING_SUPPORTED: bool | None = None
148    SUPPORTS_SINGLE_ARG_CONCAT = False
149    TABLESAMPLE_SEED_KEYWORD = "REPEATABLE"
150    SUPPORTS_SELECT_INTO = True
151    JSON_PATH_BRACKETED_KEY_SUPPORTED = False
152    SUPPORTS_TO_NUMBER = False
153    SET_OP_MODIFIERS = False
154    COPY_PARAMS_EQ_REQUIRED = True
155    PARSE_JSON_NAME: str | None = None
156    EXCEPT_INTERSECT_SUPPORT_ALL_CLAUSE = False
157    ALTER_SET_WRAPPED = True
158    ALTER_SET_TYPE = ""
159    SUPPORTS_ALTER_COLUMN_NULLABILITY = True
160
161    EXPRESSIONS_WITHOUT_NESTED_CTES = {
162        exp.Create,
163        exp.Delete,
164        exp.Insert,
165        exp.Intersect,
166        exp.Except,
167        exp.Merge,
168        exp.Select,
169        exp.Subquery,
170        exp.Union,
171        exp.Update,
172    }
173
174    SUPPORTED_JSON_PATH_PARTS = {
175        exp.JSONPathKey,
176        exp.JSONPathRoot,
177        exp.JSONPathSubscript,
178    }
179
180    TYPE_MAPPING = {
181        **{
182            k: v
183            for k, v in generator.Generator.TYPE_MAPPING.items()
184            if k not in (exp.DType.NCHAR, exp.DType.NVARCHAR)
185        },
186        exp.DType.BOOLEAN: "BIT",
187        exp.DType.DATETIME2: "DATETIME2",
188        exp.DType.DECIMAL: "NUMERIC",
189        exp.DType.DOUBLE: "FLOAT",
190        exp.DType.INT: "INTEGER",
191        exp.DType.ROWVERSION: "ROWVERSION",
192        exp.DType.TEXT: "VARCHAR(MAX)",
193        exp.DType.TIMESTAMP: "DATETIME2",
194        exp.DType.TIMESTAMPNTZ: "DATETIME2",
195        exp.DType.TIMESTAMPTZ: "DATETIMEOFFSET",
196        exp.DType.SMALLDATETIME: "SMALLDATETIME",
197        exp.DType.UTINYINT: "TINYINT",
198        exp.DType.VARIANT: "SQL_VARIANT",
199        exp.DType.UUID: "UNIQUEIDENTIFIER",
200    }
201
202    TRANSFORMS = {
203        **{k: v for k, v in generator.Generator.TRANSFORMS.items() if k != exp.ReturnsProperty},
204        exp.AnyValue: any_value_to_max_sql,
205        exp.Atan2: rename_func("ATN2"),
206        exp.ArrayToString: rename_func("STRING_AGG"),
207        exp.AutoIncrementColumnConstraint: lambda *_: "IDENTITY",
208        exp.Ceil: rename_func("CEILING"),
209        exp.Chr: rename_func("CHAR"),
210        exp.DateAdd: date_delta_sql("DATEADD"),
211        exp.CTE: transforms.preprocess([qualify_derived_table_outputs]),
212        exp.CurrentDate: rename_func("GETDATE"),
213        exp.CurrentTimestamp: rename_func("GETDATE"),
214        exp.CurrentTimestampLTZ: rename_func("SYSDATETIMEOFFSET"),
215        exp.DateStrToDate: datestrtodate_sql,
216        exp.Day: remove_ts_or_ds_to_date(),
217        exp.GeneratedAsIdentityColumnConstraint: generatedasidentitycolumnconstraint_sql,
218        exp.GroupConcat: _string_agg_sql,
219        exp.If: rename_func("IIF"),
220        exp.JSONExtract: _json_extract_sql,
221        exp.JSONExtractScalar: _json_extract_sql,
222        exp.LastDay: lambda self, e: self.func("EOMONTH", e.this),
223        exp.Ln: rename_func("LOG"),
224        exp.Max: max_or_greatest,
225        exp.MD5: lambda self, e: self.func("HASHBYTES", exp.Literal.string("MD5"), e.this),
226        exp.Min: min_or_least,
227        exp.Month: remove_ts_or_ds_to_date(),
228        exp.NumberToStr: _format_sql,
229        exp.Repeat: rename_func("REPLICATE"),
230        exp.CurrentSchema: rename_func("SCHEMA_NAME"),
231        exp.Select: transforms.preprocess(
232            [
233                transforms.eliminate_distinct_on,
234                transforms.eliminate_semi_and_anti_joins,
235                transforms.eliminate_qualify,
236                transforms.unnest_generate_date_array_using_recursive_cte,
237            ]
238        ),
239        exp.Stddev: rename_func("STDEV"),
240        exp.StrPosition: lambda self, e: strposition_sql(
241            self, e, func_name="CHARINDEX", supports_position=True
242        ),
243        exp.Subquery: transforms.preprocess([qualify_derived_table_outputs]),
244        exp.SHA: lambda self, e: self.func("HASHBYTES", exp.Literal.string("SHA1"), e.this),
245        exp.SHA1Digest: lambda self, e: self.func("HASHBYTES", exp.Literal.string("SHA1"), e.this),
246        exp.SHA2: lambda self, e: self.func(
247            "HASHBYTES", exp.Literal.string(f"SHA2_{e.args.get('length', 256)}"), e.this
248        ),
249        exp.TemporaryProperty: lambda self, e: "",
250        exp.TimeStrToTime: _timestrtotime_sql,
251        exp.TimeToStr: _format_sql,
252        exp.TimestampAdd: date_delta_sql("DATEADD"),
253        exp.Trim: trim_sql,
254        exp.TsOrDsAdd: date_delta_sql("DATEADD", cast=True),
255        exp.TsOrDsDiff: date_delta_sql("DATEDIFF"),
256        exp.TimestampTrunc: lambda self, e: self.func("DATETRUNC", e.unit, e.this),
257        exp.Trunc: lambda self, e: self.func(
258            "ROUND",
259            e.this,
260            e.args.get("decimals") or exp.Literal.number(0),
261            exp.Literal.number(1),
262        ),
263        exp.Uuid: lambda *_: "NEWID()",
264        exp.Year: remove_ts_or_ds_to_date(),
265        exp.DateFromParts: rename_func("DATEFROMPARTS"),
266    }
267
268    PROPERTIES_LOCATION = {
269        **generator.Generator.PROPERTIES_LOCATION,
270        exp.VolatileProperty: exp.Properties.Location.UNSUPPORTED,
271    }
272
273    def scope_resolution(self, rhs: str, scope_name: str) -> str:
274        return f"{scope_name}::{rhs}"
275
276    def select_sql(self, expression: exp.Select) -> str:
277        limit = expression.args.get("limit")
278        offset = expression.args.get("offset")
279
280        if isinstance(limit, exp.Fetch) and not offset:
281            # Dialects like Oracle can FETCH directly from a row set but
282            # T-SQL requires an ORDER BY + OFFSET clause in order to FETCH
283            offset = exp.Offset(expression=exp.Literal.number(0))
284            expression.set("offset", offset)
285
286        if offset:
287            if not expression.args.get("order"):
288                # ORDER BY is required in order to use OFFSET in a query, so we use
289                # a noop order by, since we don't really care about the order.
290                # See: https://www.microsoftpressstore.com/articles/article.aspx?p=2314819
291                expression.order_by(exp.select(exp.null()).subquery(), copy=False)
292
293            if isinstance(limit, exp.Limit):
294                # TOP and OFFSET can't be combined, we need use FETCH instead of TOP
295                # we replace here because otherwise TOP would be generated in select_sql
296                limit.replace(exp.Fetch(direction="FIRST", count=limit.expression))
297
298        return super().select_sql(expression)
299
300    def convert_sql(self, expression: exp.Convert) -> str:
301        name = "TRY_CONVERT" if expression.args.get("safe") else "CONVERT"
302        return self.func(name, expression.this, expression.expression, expression.args.get("style"))
303
304    def queryoption_sql(self, expression: exp.QueryOption) -> str:
305        option = self.sql(expression, "this")
306        value = self.sql(expression, "expression")
307        if value:
308            optional_equal_sign = "= " if option in OPTIONS_THAT_REQUIRE_EQUAL else ""
309            return f"{option} {optional_equal_sign}{value}"
310        return option
311
312    def lateral_op(self, expression: exp.Lateral) -> str:
313        cross_apply = expression.args.get("cross_apply")
314        if cross_apply is True:
315            return "CROSS APPLY"
316        if cross_apply is False:
317            return "OUTER APPLY"
318
319        # TODO: perhaps we can check if the parent is a Join and transpile it appropriately
320        self.unsupported("LATERAL clause is not supported.")
321        return "LATERAL"
322
323    def splitpart_sql(self, expression: exp.SplitPart) -> str:
324        this = expression.this
325        split_count = len(this.name.split("."))
326        delimiter = expression.args.get("delimiter")
327        part_index = expression.args.get("part_index")
328
329        if (
330            not all(isinstance(arg, exp.Literal) for arg in (this, delimiter, part_index))
331            or (delimiter and delimiter.name != ".")
332            or not part_index
333            or split_count > 4
334        ):
335            self.unsupported(
336                "SPLIT_PART can be transpiled to PARSENAME only for '.' delimiter and literal values"
337            )
338            return ""
339
340        return self.func(
341            "PARSENAME", this, exp.Literal.number(split_count + 1 - part_index.to_py())
342        )
343
344    def extract_sql(self, expression: exp.Extract) -> str:
345        part = expression.this
346        name = DATE_PART_UNMAPPING.get(part.name.upper()) or part
347
348        return self.func("DATEPART", name, expression.expression)
349
350    def timefromparts_sql(self, expression: exp.TimeFromParts) -> str:
351        nano = expression.args.get("nano")
352        if nano is not None:
353            nano.pop()
354            self.unsupported("Specifying nanoseconds is not supported in TIMEFROMPARTS.")
355
356        if expression.args.get("fractions") is None:
357            expression.set("fractions", exp.Literal.number(0))
358        if expression.args.get("precision") is None:
359            expression.set("precision", exp.Literal.number(0))
360
361        return rename_func("TIMEFROMPARTS")(self, expression)
362
363    def timestampfromparts_sql(self, expression: exp.TimestampFromParts) -> str:
364        zone = expression.args.get("zone")
365        if zone is not None:
366            zone.pop()
367            self.unsupported("Time zone is not supported in DATETIMEFROMPARTS.")
368
369        nano = expression.args.get("nano")
370        if nano is not None:
371            nano.pop()
372            self.unsupported("Specifying nanoseconds is not supported in DATETIMEFROMPARTS.")
373
374        if expression.args.get("milli") is None:
375            expression.set("milli", exp.Literal.number(0))
376
377        return rename_func("DATETIMEFROMPARTS")(self, expression)
378
379    def setitem_sql(self, expression: exp.SetItem) -> str:
380        this = expression.this
381        if isinstance(this, exp.EQ) and not isinstance(this.left, exp.Parameter):
382            # T-SQL does not use '=' in SET command, except when the LHS is a variable.
383            return f"{self.sql(this.left)} {self.sql(this.right)}"
384
385        return super().setitem_sql(expression)
386
387    def boolean_sql(self, expression: exp.Boolean) -> str:
388        if type(expression.parent) in BIT_TYPES or isinstance(
389            expression.find_ancestor(exp.Values, exp.Select), exp.Values
390        ):
391            return "1" if expression.this else "0"
392
393        return "(1 = 1)" if expression.this else "(1 = 0)"
394
395    def is_sql(self, expression: exp.Is) -> str:
396        negate = expression.args.get("negate")
397        if isinstance(expression.expression, exp.Boolean):
398            return self.binary(expression, "<>" if negate else "=")
399        return self.binary(expression, "IS NOT" if negate else "IS")
400
401    def createable_sql(self, expression: exp.Create, locations: defaultdict) -> str:
402        sql = self.sql(expression, "this")
403        properties = expression.args.get("properties")
404
405        start = self._identifier_start
406        if (
407            not sql.startswith("#")
408            and not sql.startswith(f"{start}#")
409            and any(
410                isinstance(prop, exp.TemporaryProperty)
411                for prop in (properties.expressions if properties else [])
412            )
413        ):
414            sql = f"{start}#{sql[len(start) :]}" if sql.startswith(start) else f"#{sql}"
415
416        return sql
417
418    def create_sql(self, expression: exp.Create) -> str:
419        kind = expression.kind
420        exists = expression.args.get("exists")
421        expression.set("exists", None)
422
423        like_property = expression.find(exp.LikeProperty)
424        if like_property:
425            ctas_expression = like_property.this
426        else:
427            ctas_expression = expression.expression
428
429        if kind == "VIEW":
430            expression.this.set("catalog", None)
431            with_ = expression.args.get("with_")
432            if ctas_expression and with_:
433                # We've already preprocessed the Create expression to bubble up any nested CTEs,
434                # but CREATE VIEW actually requires the WITH clause to come after it so we need
435                # to amend the AST by moving the CTEs to the CREATE VIEW statement's query.
436                ctas_expression.set("with_", with_.pop())
437        elif (
438            kind == "FUNCTION"
439            and isinstance(ctas_expression, exp.Return)
440            and isinstance(body := ctas_expression.this.unnest(), exp.Query)
441            and (with_ := expression.args.get("with_"))
442        ):
443            # Similar to the VIEW branch, the table-valued functions require the WITH clause
444            # to stay inside the RETURN body, so we move back any CTEs that were bubbled up.
445            body.set("with_", with_.pop())
446
447        table = expression.find(exp.Table)
448
449        # Convert CTAS statement to SELECT .. INTO ..
450        if kind == "TABLE" and ctas_expression:
451            if isinstance(ctas_expression, exp.UNWRAPPED_QUERIES):
452                ctas_expression = ctas_expression.subquery()
453
454            properties = expression.args.get("properties") or exp.Properties()
455            is_temp = any(isinstance(p, exp.TemporaryProperty) for p in properties.expressions)
456
457            select_into = exp.select("*").from_(exp.alias_(ctas_expression, "temp", table=True))
458            select_into.set("into", exp.Into(this=table, temporary=is_temp))
459
460            if like_property:
461                select_into.limit(0, copy=False)
462
463            sql = self.sql(select_into)
464        else:
465            sql = super().create_sql(expression)
466
467        if exists:
468            identifier = self.sql(exp.Literal.string(exp.table_name(table) if table else ""))
469            sql_with_ctes = self.prepend_ctes(expression, sql)
470            sql_literal = self.sql(exp.Literal.string(sql_with_ctes))
471            if kind == "SCHEMA":
472                return f"""IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = {identifier}) EXEC({sql_literal})"""
473            elif kind == "TABLE":
474                assert table
475                where = exp.and_(
476                    exp.column("TABLE_NAME").eq(table.name),
477                    exp.column("TABLE_SCHEMA").eq(table.db) if table.db else None,
478                    exp.column("TABLE_CATALOG").eq(table.catalog) if table.catalog else None,
479                )
480                return f"""IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE {where}) EXEC({sql_literal})"""
481            elif kind == "INDEX":
482                index = self.sql(exp.Literal.string(expression.this.text("this")))
483                return f"""IF NOT EXISTS (SELECT * FROM sys.indexes WHERE object_id = object_id({identifier}) AND name = {index}) EXEC({sql_literal})"""
484        elif expression.args.get("replace"):
485            sql = sql.replace("CREATE OR REPLACE ", "CREATE OR ALTER ", 1)
486
487        return self.prepend_ctes(expression, sql)
488
489    @generator.unsupported_args("unlogged", "expressions")
490    def into_sql(self, expression: exp.Into) -> str:
491        if expression.args.get("temporary"):
492            # If the Into expression has a temporary property, push this down to the Identifier
493            table = expression.find(exp.Table)
494            if table and isinstance(table.this, exp.Identifier):
495                table.this.set("temporary", True)
496
497        return f"{self.seg('INTO')} {self.sql(expression, 'this')}"
498
499    def count_sql(self, expression: exp.Count) -> str:
500        func_name = "COUNT_BIG" if expression.args.get("big_int") else "COUNT"
501        return rename_func(func_name)(self, expression)
502
503    def datediff_sql(self, expression: exp.DateDiff) -> str:
504        func_name = "DATEDIFF_BIG" if expression.args.get("big_int") else "DATEDIFF"
505        return date_delta_sql(func_name)(self, expression)
506
507    def offset_sql(self, expression: exp.Offset) -> str:
508        return f"{super().offset_sql(expression)} ROWS"
509
510    def version_sql(self, expression: exp.Version) -> str:
511        name = "SYSTEM_TIME" if expression.name == "TIMESTAMP" else expression.name
512        this = f"FOR {name}"
513        expr = expression.expression
514        kind = expression.text("kind")
515        if kind in ("FROM", "BETWEEN"):
516            args = expr.expressions
517            sep = "TO" if kind == "FROM" else "AND"
518            expr_sql = f"{self.sql(seq_get(args, 0))} {sep} {self.sql(seq_get(args, 1))}"
519        else:
520            expr_sql = self.sql(expr)
521
522        expr_sql = f" {expr_sql}" if expr_sql else ""
523        return f"{this} {kind}{expr_sql}"
524
525    def returnsproperty_sql(self, expression: exp.ReturnsProperty) -> str:
526        table = expression.args.get("table")
527        table = f"{table} " if table else ""
528        return f"RETURNS {table}{self.sql(expression, 'this')}"
529
530    def returning_sql(self, expression: exp.Returning) -> str:
531        into = self.sql(expression, "into")
532        into = self.seg(f"INTO {into}") if into else ""
533        return f"{self.seg('OUTPUT')} {self.expressions(expression, flat=True)}{into}"
534
535    def transaction_sql(self, expression: exp.Transaction) -> str:
536        this = self.sql(expression, "this")
537        this = f" {this}" if this else ""
538        mark = self.sql(expression, "mark")
539        mark = f" WITH MARK {mark}" if mark else ""
540        return f"BEGIN TRANSACTION{this}{mark}"
541
542    def commit_sql(self, expression: exp.Commit) -> str:
543        this = self.sql(expression, "this")
544        this = f" {this}" if this else ""
545        durability = expression.args.get("durability")
546        durability = (
547            f" WITH (DELAYED_DURABILITY = {'ON' if durability else 'OFF'})"
548            if durability is not None
549            else ""
550        )
551        return f"COMMIT TRANSACTION{this}{durability}"
552
553    def rollback_sql(self, expression: exp.Rollback) -> str:
554        this = self.sql(expression, "this")
555        this = f" {this}" if this else ""
556        return f"ROLLBACK TRANSACTION{this}"
557
558    def identifier_sql(self, expression: exp.Identifier) -> str:
559        identifier = super().identifier_sql(expression)
560
561        if expression.args.get("global_"):
562            prefix = "##"
563        elif expression.args.get("temporary"):
564            prefix = "#"
565        else:
566            return identifier
567
568        start = self._identifier_start
569        if expression.quoted and identifier.startswith(start):
570            return f"{start}{prefix}{identifier[len(start) :]}"
571
572        return f"{prefix}{identifier}"
573
574    def constraint_sql(self, expression: exp.Constraint) -> str:
575        this = self.sql(expression, "this")
576        expressions = self.expressions(expression, flat=True, sep=" ")
577        return f"CONSTRAINT {this} {expressions}"
578
579    def length_sql(self, expression: exp.Length) -> str:
580        return self._uncast_text(expression, "LEN")
581
582    def right_sql(self, expression: exp.Right) -> str:
583        return self._uncast_text(expression, "RIGHT")
584
585    def left_sql(self, expression: exp.Left) -> str:
586        return self._uncast_text(expression, "LEFT")
587
588    def _uncast_text(self, expression: exp.Expr, name: str) -> str:
589        this = expression.this
590        if isinstance(this, exp.Cast) and this.is_type(exp.DType.TEXT):
591            this_sql = self.sql(this, "this")
592        else:
593            this_sql = self.sql(this)
594        expression_sql = self.sql(expression, "expression")
595        return self.func(name, this_sql, expression_sql if expression_sql else None)
596
597    def partition_sql(self, expression: exp.Partition) -> str:
598        return f"WITH (PARTITIONS({self.expressions(expression, flat=True)}))"
599
600    def alter_sql(self, expression: exp.Alter) -> str:
601        action = seq_get(expression.args.get("actions") or [], 0)
602        if isinstance(action, exp.AlterRename):
603            return f"EXEC sp_rename '{self.sql(expression.this)}', '{action.this.name}'"
604        return super().alter_sql(expression)
605
606    def drop_sql(self, expression: exp.Drop) -> str:
607        if expression.args["kind"] == "VIEW":
608            for table in expression.args.get("tables") or []:
609                table.set("catalog", None)
610        return super().drop_sql(expression)
611
612    def options_modifier(self, expression: exp.Expr) -> str:
613        options = self.expressions(expression, key="options")
614        return f" OPTION{self.wrap(options)}" if options else ""
615
616    def dpipe_sql(self, expression: exp.DPipe) -> str:
617        return self.sql(reduce(lambda x, y: exp.Add(this=x, expression=y), expression.flatten()))
618
619    def isascii_sql(self, expression: exp.IsAscii) -> str:
620        return f"(PATINDEX(CONVERT(VARCHAR(MAX), 0x255b5e002d7f5d25) COLLATE Latin1_General_BIN, {self.sql(expression.this)}) = 0)"
621
622    def columndef_sql(self, expression: exp.ColumnDef, sep: str = " ") -> str:
623        this = super().columndef_sql(expression, sep)
624        default = self.sql(expression, "default")
625        default = f" = {default}" if default else ""
626        output = self.sql(expression, "output")
627        output = f" {output}" if output else ""
628        return f"{this}{default}{output}"
629
630    def coalesce_sql(self, expression: exp.Coalesce) -> str:
631        func_name = "ISNULL" if expression.args.get("is_null") else "COALESCE"
632        return rename_func(func_name)(self, expression)
633
634    def storedprocedure_sql(self, expression: exp.StoredProcedure) -> str:
635        this = self.sql(expression, "this")
636        expressions = self.expressions(expression)
637        expressions = (
638            self.wrap(expressions) if expression.args.get("wrapped") else f" {expressions}"
639        )
640        return f"{this}{expressions}" if expressions.strip() != "" else this
641
642    def ifblock_sql(self, expression: exp.IfBlock) -> str:
643        this = self.sql(expression, "this")
644        true = self.sql(expression, "true")
645        true = f" {true}" if true else " "
646        false = self.sql(expression, "false")
647        false = f"; ELSE BEGIN {false}" if false else ""
648        return f"IF {this} BEGIN{true}{false}"
649
650    def whileblock_sql(self, expression: exp.WhileBlock) -> str:
651        this = self.sql(expression, "this")
652        body = self.sql(expression, "body")
653        body = f" {body}" if body else " "
654        return f"WHILE {this} BEGIN{body}"
655
656    def execute_sql(self, expression: exp.Execute) -> str:
657        this = self.sql(expression, "this")
658        expressions = self.expressions(expression)
659        expressions = f" {expressions}" if expressions else ""
660        return_status = self.sql(expression, "return_status")
661        return_status = f"{return_status} = " if return_status else ""
662        return f"EXECUTE {return_status}{this}{expressions}"
663
664    def executesql_sql(self, expression: exp.ExecuteSql) -> str:
665        return self.execute_sql(expression)