Fix: expand laterals first if no schema is present

sqlglot/optimizer/expand_laterals.py

@@ -29,6 +29,6 @@ def expand_laterals(expression: exp.Expression) -> exp.Expression:
             for column in projection.find_all(exp.Column):
                 if not column.table and column.name in alias_to_expression:
                     column.replace(alias_to_expression[column.name].copy())
-                if isinstance(projection, exp.Alias):
-                    alias_to_expression[projection.alias] = projection.this
+            if isinstance(projection, exp.Alias):
+                alias_to_expression[projection.alias] = projection.this
     return expression

sqlglot/optimizer/optimizer.py

@@ -10,7 +10,6 @@
 from sqlglot.optimizer.eliminate_ctes import eliminate_ctes
 from sqlglot.optimizer.eliminate_joins import eliminate_joins
 from sqlglot.optimizer.eliminate_subqueries import eliminate_subqueries
-from sqlglot.optimizer.expand_laterals import expand_laterals
 from sqlglot.optimizer.expand_multi_table_selects import expand_multi_table_selects
 from sqlglot.optimizer.isolate_table_selects import isolate_table_selects
 from sqlglot.optimizer.lower_identities import lower_identities
@@ -30,7 +29,6 @@
     qualify_tables,
     isolate_table_selects,
     qualify_columns,
-    expand_laterals,
     pushdown_projections,
     validate_qualify_columns,
     normalize,

sqlglot/optimizer/qualify_columns.py

@@ -3,11 +3,12 @@
 
 from sqlglot import alias, exp
 from sqlglot.errors import OptimizeError
+from sqlglot.optimizer.expand_laterals import expand_laterals as _expand_laterals
 from sqlglot.optimizer.scope import Scope, traverse_scope
 from sqlglot.schema import ensure_schema
 
 
-def qualify_columns(expression, schema):
+def qualify_columns(expression, schema, expand_laterals=True):
     """
     Rewrite sqlglot AST to have fully qualified columns.
 
@@ -26,6 +27,9 @@ def qualify_columns(expression, schema):
     """
     schema = ensure_schema(schema)
 
+    if not schema.mapping and expand_laterals:
+        expression = _expand_laterals(expression)
+
     for scope in traverse_scope(expression):
         resolver = Resolver(scope, schema)
         _pop_table_column_aliases(scope.ctes)
@@ -39,6 +43,9 @@ def qualify_columns(expression, schema):
         _expand_group_by(scope, resolver)
         _expand_order_by(scope)
 
+    if schema.mapping and expand_laterals:
+        expression = _expand_laterals(expression)
+
     return expression
 
 

tests/test_optimizer.py

@@ -221,6 +221,12 @@ def test_pushdown_predicates(self):
         self.check_file("pushdown_predicates", optimizer.pushdown_predicates.pushdown_predicates)
 
     def test_expand_laterals(self):
+        # check order of lateral expansion with no schema
+        self.assertEqual(
+            optimizer.optimize("SELECT a + 1 AS d, d + 1 AS e FROM x " "").sql(),
+            'SELECT "x"."a" + 1 AS "d", "x"."a" + 2 AS "e" FROM "x" AS "x"',
+        )
+
         self.check_file(
             "expand_laterals",
             optimizer.expand_laterals.expand_laterals,