-- -- Tests for functions that return void -- CREATE FUNCTION test_void_func1() RETURNS void AS $$ x = 10 $$ LANGUAGE plpython3u; -- illegal: can't return non-None value in void-returning func CREATE FUNCTION test_void_func2() RETURNS void AS $$ return 10 $$ LANGUAGE plpython3u; CREATE FUNCTION test_return_none() RETURNS int AS $$ None $$ LANGUAGE plpython3u; -- Tests for functions returning void SELECT test_void_func1(), test_void_func1() IS NULL AS "is null"; test_void_func1 | is null -----------------+--------- | f (1 row) SELECT test_void_func2(); -- should fail ERROR: PL/Python function with return type "void" did not return None CONTEXT: while creating return value PL/Python function "test_void_func2" SELECT test_return_none(), test_return_none() IS NULL AS "is null"; test_return_none | is null ------------------+--------- | t (1 row)