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 infer_schema: t.Optional[bool] = None, 27 isolate_tables: bool = False, 28 qualify_columns: bool = True, 29 validate_qualify_columns: bool = True, 30 quote_identifiers: bool = True, 31 identify: bool = True, 32) -> exp.Expression: 33 """ 34 Rewrite sqlglot AST to have normalized and qualified tables and columns. 35 36 This step is necessary for all further SQLGlot optimizations. 37 38 Example: 39 >>> import sqlglot 40 >>> schema = {"tbl": {"col": "INT"}} 41 >>> expression = sqlglot.parse_one("SELECT col FROM tbl") 42 >>> qualify(expression, schema=schema).sql() 43 'SELECT "tbl"."col" AS "col" FROM "tbl" AS "tbl"' 44 45 Args: 46 expression: Expression to qualify. 47 db: Default database name for tables. 48 catalog: Default catalog name for tables. 49 schema: Schema to infer column names and types. 50 expand_alias_refs: Whether or not to expand references to aliases. 51 infer_schema: Whether or not to infer the schema if missing. 52 isolate_tables: Whether or not to isolate table selects. 53 qualify_columns: Whether or not to qualify columns. 54 validate_qualify_columns: Whether or not to validate columns. 55 quote_identifiers: Whether or not to run the quote_identifiers step. 56 This step is necessary to ensure correctness for case sensitive queries. 57 But this flag is provided in case this step is performed at a later time. 58 identify: If True, quote all identifiers, else only necessary ones. 59 60 Returns: 61 The qualified expression. 62 """ 63 schema = ensure_schema(schema, dialect=dialect) 64 expression = normalize_identifiers(expression, dialect=dialect) 65 expression = qualify_tables(expression, db=db, catalog=catalog, schema=schema) 66 67 if isolate_tables: 68 expression = isolate_table_selects(expression, schema=schema) 69 70 if Dialect.get_or_raise(dialect).PREFER_CTE_ALIAS_COLUMN: 71 expression = pushdown_cte_alias_columns_func(expression) 72 73 if qualify_columns: 74 expression = qualify_columns_func( 75 expression, schema, expand_alias_refs=expand_alias_refs, infer_schema=infer_schema 76 ) 77 78 if quote_identifiers: 79 expression = quote_identifiers_func(expression, dialect=dialect, identify=identify) 80 81 if validate_qualify_columns: 82 validate_qualify_columns_func(expression) 83 84 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, 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) -> 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 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) -> exp.Expression: 34 """ 35 Rewrite sqlglot AST to have normalized and qualified tables and columns. 36 37 This step is necessary for all further SQLGlot optimizations. 38 39 Example: 40 >>> import sqlglot 41 >>> schema = {"tbl": {"col": "INT"}} 42 >>> expression = sqlglot.parse_one("SELECT col FROM tbl") 43 >>> qualify(expression, schema=schema).sql() 44 'SELECT "tbl"."col" AS "col" FROM "tbl" AS "tbl"' 45 46 Args: 47 expression: Expression to qualify. 48 db: Default database name for tables. 49 catalog: Default catalog name for tables. 50 schema: Schema to infer column names and types. 51 expand_alias_refs: Whether or not to expand references to aliases. 52 infer_schema: Whether or not to infer the schema if missing. 53 isolate_tables: Whether or not to isolate table selects. 54 qualify_columns: Whether or not to qualify columns. 55 validate_qualify_columns: Whether or not to validate columns. 56 quote_identifiers: Whether or not to run the quote_identifiers step. 57 This step is necessary to ensure correctness for case sensitive queries. 58 But this flag is provided in case this step is performed at a later time. 59 identify: If True, quote all identifiers, else only necessary ones. 60 61 Returns: 62 The qualified expression. 63 """ 64 schema = ensure_schema(schema, dialect=dialect) 65 expression = normalize_identifiers(expression, dialect=dialect) 66 expression = qualify_tables(expression, db=db, catalog=catalog, schema=schema) 67 68 if isolate_tables: 69 expression = isolate_table_selects(expression, schema=schema) 70 71 if Dialect.get_or_raise(dialect).PREFER_CTE_ALIAS_COLUMN: 72 expression = pushdown_cte_alias_columns_func(expression) 73 74 if qualify_columns: 75 expression = qualify_columns_func( 76 expression, schema, expand_alias_refs=expand_alias_refs, infer_schema=infer_schema 77 ) 78 79 if quote_identifiers: 80 expression = quote_identifiers_func(expression, dialect=dialect, identify=identify) 81 82 if validate_qualify_columns: 83 validate_qualify_columns_func(expression) 84 85 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 or not to expand references to aliases.
- infer_schema: Whether or not to infer the schema if missing.
- isolate_tables: Whether or not to isolate table selects.
- qualify_columns: Whether or not to qualify columns.
- validate_qualify_columns: Whether or not to validate columns.
- quote_identifiers: Whether or not 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.
Returns:
The qualified expression.