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Adding upstream version 17.3.0.

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Signed-off-by: Daniel Baumann <daniel@debian.org>
This commit is contained in:
Daniel Baumann 2025-02-13 20:43:42 +01:00
parent fbce006e29
commit d28371fcc4
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
43 changed files with 5488 additions and 5047 deletions
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34
sqlglot/optimizer/qualify_tables.py
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@ -15,8 +15,7 @@ def qualify_tables(
schema: t.Optional[Schema] = None,
) -> E:
"""
Rewrite sqlglot AST to have fully qualified tables. Additionally, this
replaces "join constructs" (*) by equivalent SELECT * subqueries.
Rewrite sqlglot AST to have fully qualified, unnested tables.
Examples:
>>> import sqlglot
@ -24,9 +23,18 @@ def qualify_tables(
>>> qualify_tables(expression, db="db").sql()
'SELECT 1 FROM db.tbl AS tbl'
>>>
>>> expression = sqlglot.parse_one("SELECT * FROM (tbl)")
>>> qualify_tables(expression).sql()
'SELECT * FROM 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'
'SELECT * FROM tbl1 AS tbl1 JOIN tbl2 AS tbl2 ON id1 = id2'
Note:
This rule effectively enforces a left-to-right join order, since all joins
are unnested. This means that the optimizer doesn't necessarily preserve the
original join order, e.g. when parentheses are used to specify it explicitly.
Args:
expression: Expression to qualify
@ -36,19 +44,11 @@ def qualify_tables(
Returns:
The qualified expression.
(*) See section 7.2.1.2 in https://www.postgresql.org/docs/current/queries-table-expressions.html
"""
next_alias_name = name_sequence("_q_")
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_ = next_alias_name()
derived_table.set("alias", exp.TableAlias(this=exp.to_identifier(alias_)))
@ -66,13 +66,17 @@ def qualify_tables(
if not source.args.get("catalog"):
source.set("catalog", exp.to_identifier(catalog))
# Unnest joins attached in tables by appending them to the closest query
for join in source.args.get("joins") or []:
scope.expression.append("joins", join)
source.set("joins", None)
source.set("wrapped", None)
if not source.alias:
source = source.replace(
alias(
source,
name or source.name or next_alias_name(),
copy=True,
table=True,
source, name or source.name or next_alias_name(), copy=True, table=True
)
)