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Adding upstream version 12.2.0.

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Signed-off-by: Daniel Baumann <daniel@debian.org>
This commit is contained in:
Daniel Baumann 2025-02-13 15:52:54 +01:00
parent 82a8846a46
commit 70d5d3451a
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
100 changed files with 35022 additions and 30936 deletions
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18
sqlglot/optimizer/qualify_tables.py
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@ -7,21 +7,29 @@ from sqlglot.optimizer.scope import Scope, traverse_scope
def qualify_tables(expression, db=None, catalog=None, schema=None):
"""
Rewrite sqlglot AST to have fully qualified tables.
Rewrite sqlglot AST to have fully qualified tables. Additionally, this
replaces "join constructs" (*) by equivalent SELECT * subqueries.
Example:
Examples:
>>> import sqlglot
>>> expression = sqlglot.parse_one("SELECT 1 FROM tbl")
>>> qualify_tables(expression, db="db").sql()
'SELECT 1 FROM db.tbl AS tbl'
>>>
>>> expression = sqlglot.parse_one("SELECT * FROM (tbl1 JOIN tbl2 ON id1 = id2)")
>>> qualify_tables(expression).sql()
'SELECT * FROM (SELECT * FROM tbl1 AS tbl1 JOIN tbl2 AS tbl2 ON id1 = id2) AS _q_0'
Args:
expression (sqlglot.Expression): expression to qualify
db (str): Database name
catalog (str): Catalog name
schema: A schema to populate
Returns:
sqlglot.Expression: qualified expression
(*) See section 7.2.1.2 in https://www.postgresql.org/docs/current/queries-table-expressions.html
"""
sequence = itertools.count()
@ -29,6 +37,12 @@ def qualify_tables(expression, db=None, catalog=None, schema=None):
for scope in traverse_scope(expression):
for derived_table in itertools.chain(scope.ctes, scope.derived_tables):
# Expand join construct
if isinstance(derived_table, exp.Subquery):
unnested = derived_table.unnest()
if isinstance(unnested, exp.Table):
derived_table.this.replace(exp.select("*").from_(unnested.copy(), copy=False))
if not derived_table.args.get("alias"):
alias_ = f"_q_{next(sequence)}"
derived_table.set("alias", exp.TableAlias(this=exp.to_identifier(alias_)))