feat(parser): parse CALLED ON NULL INPUT as a property instead of Command

Author: eruditmorina

sqlglot/expressions/properties.py

@@ -63,6 +63,10 @@ class BlockCompressionProperty(Property):
     }
 
 
+class CalledOnNullInputProperty(Property):
+    arg_types = {}
+
+
 class CatalogProperty(Property):
     arg_types = {}
 

sqlglot/generator.py

@@ -149,6 +149,7 @@ class Generator:
         exp.CaseSpecificColumnConstraint: lambda _, e: (
             f"{'NOT ' if e.args.get('not_') else ''}CASESPECIFIC"
         ),
+        exp.CalledOnNullInputProperty: lambda *_: "CALLED ON NULL INPUT",
         exp.Ceil: lambda self, e: self.ceil_floor(e),
         exp.CharacterSetColumnConstraint: lambda self, e: f"CHARACTER SET {self.sql(e, 'this')}",
         exp.CharacterSetProperty: lambda self, e: (
@@ -677,6 +678,7 @@ class Generator:
         exp.AutoRefreshProperty: exp.Properties.Location.POST_SCHEMA,
         exp.BackupProperty: exp.Properties.Location.POST_SCHEMA,
         exp.BlockCompressionProperty: exp.Properties.Location.POST_NAME,
+        exp.CalledOnNullInputProperty: exp.Properties.Location.POST_SCHEMA,
         exp.CatalogProperty: exp.Properties.Location.POST_CREATE,
         exp.CharacterSetProperty: exp.Properties.Location.POST_SCHEMA,
         exp.ChecksumProperty: exp.Properties.Location.POST_NAME,

sqlglot/parser.py

@@ -1236,6 +1236,7 @@ class Parser:
             exp.BackupProperty(this=self._parse_var(any_token=True))
         ),
         "BLOCKCOMPRESSION": lambda self: self._parse_blockcompression(),
+        "CALLED": lambda self: self._parse_called_on_null_input_property(),
         "CHARSET": lambda self, **kwargs: self._parse_character_set(**kwargs),
         "CHARACTER SET": lambda self, **kwargs: self._parse_character_set(**kwargs),
         "CHECKSUM": lambda self: self._parse_checksum(),
@@ -2900,6 +2901,14 @@ def _parse_settings_property(self) -> exp.SettingsProperty:
             exp.SettingsProperty(expressions=self._parse_csv(self._parse_assignment))
         )
 
+    def _parse_called_on_null_input_property(self) -> exp.CalledOnNullInputProperty | None:
+        index = self._index
+        if self._match_text_seq("ON", "NULL", "INPUT"):
+            return self.expression(exp.CalledOnNullInputProperty())
+
+        self._retreat(index - 1)
+        return None
+
     def _parse_volatile_property(self) -> exp.VolatileProperty | exp.StabilityProperty:
         if self._index >= 2:
             pre_volatile_token = self._tokens[self._index - 2]

tests/dialects/test_postgres.py

@@ -1292,8 +1292,8 @@ def test_ddl(self):
         )
         self.validate_identity(
             "CREATE FUNCTION add(integer, integer) RETURNS integer AS 'select $1 + $2;' LANGUAGE SQL IMMUTABLE CALLED ON NULL INPUT",
-            check_command_warning=True,
-        )
+            "CREATE FUNCTION add(integer, integer) RETURNS INT LANGUAGE SQL IMMUTABLE CALLED ON NULL INPUT AS 'select $1 + $2;'",
+        ).assert_is(exp.Create)
         self.validate_identity(
             "CREATE CONSTRAINT TRIGGER my_trigger AFTER INSERT OR DELETE OR UPDATE OF col_a, col_b ON public.my_table DEFERRABLE INITIALLY DEFERRED FOR EACH ROW EXECUTE FUNCTION DO_STH()"
         )

tests/dialects/test_snowflake.py

@@ -4322,7 +4322,7 @@ def test_ddl(self):
         )
         self.validate_identity(
             """CREATE OR REPLACE FUNCTION ibis_udfs.public.object_values("obj" OBJECT) RETURNS ARRAY LANGUAGE JAVASCRIPT RETURNS NULL ON NULL INPUT AS ' return Object.values(obj) '"""
-        )
+        ).assert_is(exp.Create)
         self.validate_identity(
             """CREATE OR REPLACE FUNCTION ibis_udfs.public.object_values("obj" OBJECT) RETURNS ARRAY LANGUAGE JAVASCRIPT STRICT AS ' return Object.values(obj) '"""
         )
@@ -4427,6 +4427,10 @@ def test_user_defined_functions(self):
                 "snowflake": "CREATE FUNCTION a() RETURNS INT IMMUTABLE AS 'SELECT 1'",
             },
         )
+        self.validate_identity(
+            "CREATE FUNCTION a(x FLOAT) RETURNS FLOAT LANGUAGE SQL CALLED ON NULL INPUT AS $$ RETURN x * 2; $$",
+            "CREATE FUNCTION a(x DOUBLE) RETURNS DOUBLE LANGUAGE SQL CALLED ON NULL INPUT AS ' RETURN x * 2; '",
+        ).assert_is(exp.Create)
 
         self.validate_identity(
             "CREATE OR REPLACE FUNCTION repro_fn() RETURNS INT LANGUAGE PYTHON HANDLER = 'fn' RUNTIME_VERSION='3.11' PACKAGES=() AS '\\ndef fn():\\n    return 1\\n'"

tests/fixtures/identity.sql

@@ -632,6 +632,7 @@ CREATE FUNCTION a.b(x INT) RETURNS INT AS RETURN x + 1
 CREATE FUNCTION a.b(x TEXT) RETURNS TEXT CONTAINS SQL AS RETURN x
 CREATE FUNCTION a.b(x TEXT) RETURNS TEXT LANGUAGE SQL MODIFIES SQL DATA AS RETURN x
 CREATE FUNCTION a.b(x TEXT) LANGUAGE SQL READS SQL DATA RETURNS TEXT AS RETURN x
+CREATE FUNCTION a(x INT) RETURNS INT LANGUAGE SQL CALLED ON NULL INPUT AS 'SELECT 1'
 CREATE FUNCTION a.b.c()
 CREATE INDEX abc ON t(a)
 CREATE INDEX "abc" ON t(a)