sqlglot.optimizer.qualify
1from __future__ import annotations 2 3import typing as t 4 5from sqlglot import exp 6from sqlglot.dialects.dialect import Dialect, DialectType 7from sqlglot.optimizer.isolate_table_selects import isolate_table_selects 8from sqlglot.optimizer.normalize_identifiers import normalize_identifiers 9from sqlglot.optimizer.qualify_columns import ( 10 pushdown_cte_alias_columns as pushdown_cte_alias_columns_func, 11 qualify_columns as qualify_columns_func, 12 quote_identifiers as quote_identifiers_func, 13 validate_qualify_columns as validate_qualify_columns_func, 14) 15from sqlglot.optimizer.qualify_tables import qualify_tables 16from sqlglot.schema import Schema, ensure_schema 17 18 19def qualify( 20 expression: exp.Expression, 21 dialect: DialectType = None, 22 db: t.Optional[str] = None, 23 catalog: t.Optional[str] = None, 24 schema: t.Optional[dict | Schema] = None, 25 expand_alias_refs: bool = True, 26 expand_stars: bool = True, 27 infer_schema: t.Optional[bool] = None, 28 isolate_tables: bool = False, 29 qualify_columns: bool = True, 30 validate_qualify_columns: bool = True, 31 quote_identifiers: bool = True, 32 identify: bool = True, 33 infer_csv_schemas: bool = False, 34) -> exp.Expression: 35 """ 36 Rewrite sqlglot AST to have normalized and qualified tables and columns. 37 38 This step is necessary for all further SQLGlot optimizations. 39 40 Example: 41 >>> import sqlglot 42 >>> schema = {"tbl": {"col": "INT"}} 43 >>> expression = sqlglot.parse_one("SELECT col FROM tbl") 44 >>> qualify(expression, schema=schema).sql() 45 'SELECT "tbl"."col" AS "col" FROM "tbl" AS "tbl"' 46 47 Args: 48 expression: Expression to qualify. 49 db: Default database name for tables. 50 catalog: Default catalog name for tables. 51 schema: Schema to infer column names and types. 52 expand_alias_refs: Whether to expand references to aliases. 53 expand_stars: Whether to expand star queries. This is a necessary step 54 for most of the optimizer's rules to work; do not set to False unless you 55 know what you're doing! 56 infer_schema: Whether to infer the schema if missing. 57 isolate_tables: Whether to isolate table selects. 58 qualify_columns: Whether to qualify columns. 59 validate_qualify_columns: Whether to validate columns. 60 quote_identifiers: Whether to run the quote_identifiers step. 61 This step is necessary to ensure correctness for case sensitive queries. 62 But this flag is provided in case this step is performed at a later time. 63 identify: If True, quote all identifiers, else only necessary ones. 64 infer_csv_schemas: Whether to scan READ_CSV calls in order to infer the CSVs' schemas. 65 66 Returns: 67 The qualified expression. 68 """ 69 schema = ensure_schema(schema, dialect=dialect) 70 expression = normalize_identifiers(expression, dialect=dialect) 71 expression = qualify_tables( 72 expression, 73 db=db, 74 catalog=catalog, 75 schema=schema, 76 dialect=dialect, 77 infer_csv_schemas=infer_csv_schemas, 78 ) 79 80 if isolate_tables: 81 expression = isolate_table_selects(expression, schema=schema) 82 83 if Dialect.get_or_raise(dialect).PREFER_CTE_ALIAS_COLUMN: 84 expression = pushdown_cte_alias_columns_func(expression) 85 86 if qualify_columns: 87 expression = qualify_columns_func( 88 expression, 89 schema, 90 expand_alias_refs=expand_alias_refs, 91 expand_stars=expand_stars, 92 infer_schema=infer_schema, 93 ) 94 95 if quote_identifiers: 96 expression = quote_identifiers_func(expression, dialect=dialect, identify=identify) 97 98 if validate_qualify_columns: 99 validate_qualify_columns_func(expression) 100 101 return expression
def
qualify( expression: sqlglot.expressions.Expression, dialect: Union[str, sqlglot.dialects.dialect.Dialect, Type[sqlglot.dialects.dialect.Dialect], NoneType] = None, db: Optional[str] = None, catalog: Optional[str] = None, schema: Union[dict, sqlglot.schema.Schema, NoneType] = None, expand_alias_refs: bool = True, expand_stars: bool = True, infer_schema: Optional[bool] = None, isolate_tables: bool = False, qualify_columns: bool = True, validate_qualify_columns: bool = True, quote_identifiers: bool = True, identify: bool = True, infer_csv_schemas: bool = False) -> sqlglot.expressions.Expression:
20def qualify( 21 expression: exp.Expression, 22 dialect: DialectType = None, 23 db: t.Optional[str] = None, 24 catalog: t.Optional[str] = None, 25 schema: t.Optional[dict | Schema] = None, 26 expand_alias_refs: bool = True, 27 expand_stars: bool = True, 28 infer_schema: t.Optional[bool] = None, 29 isolate_tables: bool = False, 30 qualify_columns: bool = True, 31 validate_qualify_columns: bool = True, 32 quote_identifiers: bool = True, 33 identify: bool = True, 34 infer_csv_schemas: bool = False, 35) -> exp.Expression: 36 """ 37 Rewrite sqlglot AST to have normalized and qualified tables and columns. 38 39 This step is necessary for all further SQLGlot optimizations. 40 41 Example: 42 >>> import sqlglot 43 >>> schema = {"tbl": {"col": "INT"}} 44 >>> expression = sqlglot.parse_one("SELECT col FROM tbl") 45 >>> qualify(expression, schema=schema).sql() 46 'SELECT "tbl"."col" AS "col" FROM "tbl" AS "tbl"' 47 48 Args: 49 expression: Expression to qualify. 50 db: Default database name for tables. 51 catalog: Default catalog name for tables. 52 schema: Schema to infer column names and types. 53 expand_alias_refs: Whether to expand references to aliases. 54 expand_stars: Whether to expand star queries. This is a necessary step 55 for most of the optimizer's rules to work; do not set to False unless you 56 know what you're doing! 57 infer_schema: Whether to infer the schema if missing. 58 isolate_tables: Whether to isolate table selects. 59 qualify_columns: Whether to qualify columns. 60 validate_qualify_columns: Whether to validate columns. 61 quote_identifiers: Whether to run the quote_identifiers step. 62 This step is necessary to ensure correctness for case sensitive queries. 63 But this flag is provided in case this step is performed at a later time. 64 identify: If True, quote all identifiers, else only necessary ones. 65 infer_csv_schemas: Whether to scan READ_CSV calls in order to infer the CSVs' schemas. 66 67 Returns: 68 The qualified expression. 69 """ 70 schema = ensure_schema(schema, dialect=dialect) 71 expression = normalize_identifiers(expression, dialect=dialect) 72 expression = qualify_tables( 73 expression, 74 db=db, 75 catalog=catalog, 76 schema=schema, 77 dialect=dialect, 78 infer_csv_schemas=infer_csv_schemas, 79 ) 80 81 if isolate_tables: 82 expression = isolate_table_selects(expression, schema=schema) 83 84 if Dialect.get_or_raise(dialect).PREFER_CTE_ALIAS_COLUMN: 85 expression = pushdown_cte_alias_columns_func(expression) 86 87 if qualify_columns: 88 expression = qualify_columns_func( 89 expression, 90 schema, 91 expand_alias_refs=expand_alias_refs, 92 expand_stars=expand_stars, 93 infer_schema=infer_schema, 94 ) 95 96 if quote_identifiers: 97 expression = quote_identifiers_func(expression, dialect=dialect, identify=identify) 98 99 if validate_qualify_columns: 100 validate_qualify_columns_func(expression) 101 102 return expression
Rewrite sqlglot AST to have normalized and qualified tables and columns.
This step is necessary for all further SQLGlot optimizations.
Example:
>>> import sqlglot >>> schema = {"tbl": {"col": "INT"}} >>> expression = sqlglot.parse_one("SELECT col FROM tbl") >>> qualify(expression, schema=schema).sql() 'SELECT "tbl"."col" AS "col" FROM "tbl" AS "tbl"'
Arguments:
- expression: Expression to qualify.
- db: Default database name for tables.
- catalog: Default catalog name for tables.
- schema: Schema to infer column names and types.
- expand_alias_refs: Whether to expand references to aliases.
- expand_stars: Whether to expand star queries. This is a necessary step for most of the optimizer's rules to work; do not set to False unless you know what you're doing!
- infer_schema: Whether to infer the schema if missing.
- isolate_tables: Whether to isolate table selects.
- qualify_columns: Whether to qualify columns.
- validate_qualify_columns: Whether to validate columns.
- quote_identifiers: Whether to run the quote_identifiers step. This step is necessary to ensure correctness for case sensitive queries. But this flag is provided in case this step is performed at a later time.
- identify: If True, quote all identifiers, else only necessary ones.
- infer_csv_schemas: Whether to scan READ_CSV calls in order to infer the CSVs' schemas.
Returns:
The qualified expression.