Feat(postgres): support laterals with ordinality fixes #4965 (#4966)

Author: georgesittas

sqlglot/expressions.py

@@ -2584,6 +2584,7 @@ class Lateral(UDTF):
         "outer": False,
         "alias": False,
         "cross_apply": False,  # True -> CROSS APPLY, False -> OUTER APPLY
+        "ordinality": False,
     }
 
 

sqlglot/generator.py

@@ -2307,7 +2307,13 @@ def lateral_sql(self, expression: exp.Lateral) -> str:
 
         alias = self.sql(expression, "alias")
         alias = f" AS {alias}" if alias else ""
-        return f"{self.lateral_op(expression)} {this}{alias}"
+
+        ordinality = expression.args.get("ordinality") or ""
+        if ordinality:
+            ordinality = f" WITH ORDINALITY{alias}"
+            alias = ""
+
+        return f"{self.lateral_op(expression)} {this}{alias}{ordinality}"
 
     def limit_sql(self, expression: exp.Limit, top: bool = False) -> str:
         this = self.sql(expression, "this")

sqlglot/parser.py

@@ -3576,6 +3576,8 @@ def _parse_lateral(self) -> t.Optional[exp.Lateral]:
                     expression=self._parse_function() or self._parse_id_var(any_token=False),
                 )
 
+        ordinality: t.Optional[bool] = None
+
         if view:
             table = self._parse_id_var(any_token=False)
             columns = self._parse_csv(self._parse_id_var) if self._match(TokenType.ALIAS) else []
@@ -3586,6 +3588,7 @@ def _parse_lateral(self) -> t.Optional[exp.Lateral]:
             # We move the alias from the lateral's child node to the lateral itself
             table_alias = this.args["alias"].pop()
         else:
+            ordinality = self._match_pair(TokenType.WITH, TokenType.ORDINALITY)
             table_alias = self._parse_table_alias()
 
         return self.expression(
@@ -3595,6 +3598,7 @@ def _parse_lateral(self) -> t.Optional[exp.Lateral]:
             outer=outer,
             alias=table_alias,
             cross_apply=cross_apply,
+            ordinality=ordinality,
         )
 
     def _parse_join_parts(

tests/dialects/test_postgres.py

@@ -76,6 +76,9 @@ def test_postgres(self):
         self.validate_identity("SELECT CURRENT_SCHEMA")
         self.validate_identity("SELECT CURRENT_USER")
         self.validate_identity("SELECT * FROM ONLY t1")
+        self.validate_identity(
+            "SELECT * FROM test_data, LATERAL JSONB_ARRAY_ELEMENTS(data) WITH ORDINALITY AS elem(value, ordinality)"
+        )
         self.validate_identity(
             "SELECT id, name FROM xml_data AS t, XMLTABLE('/root/user' PASSING t.xml COLUMNS id INT PATH '@id', name TEXT PATH 'name/text()') AS x"
         )