postgreSQL插入分区触发器

CREATE OR REPLACE FUNCTION insert_before_to_partition()
RETURNS trigger AS
$BODY$
BEGIN
EXECUTE format('INSERT INTO %I SELECT ($1).*', TG_TABLE_NAME||'_'||NEW.year_month)
USING NEW;
RETURN NULL;
EXCEPTION WHEN UNDEFINED_TABLE THEN
RAISE EXCEPTION 'year_month out of range. please create table or check the data %ERROR:  % %SQL 状态: %',chr(10),SQLERRM,chr(10),SQLSTATE;
WHEN OTHERS THEN
RAISE EXCEPTION '% %SQL 状态: %', SQLERRM,chr(10),SQLSTATE;
END
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;