CREATE OR REPLACE FUNCTION fn_log_audit() RETURNS TRIGGER AS
$$
BEGIN
  IF (TG_OP = 'DELETE') THEN
    INSERT INTO basicos.tbl_audit ("TableName", "Operation", "OldValue", "NewValue", "UpdateDate", "UserName")
           VALUES (TG_TABLE_NAME, 'D', OLD, NULL, now(), usuario_logueado());
RETURN OLD;
  ELSIF (TG_OP = 'UPDATE') THEN
    INSERT INTO basicos.tbl_audit ("TableName", "Operation", "OldValue", "NewValue", "UpdateDate", "UserName")
           VALUES (TG_TABLE_NAME, 'U', OLD, NEW, now(), USER);
RETURN NEW;
  ELSIF (TG_OP = 'INSERT') THEN
    INSERT INTO basicos.tbl_audit ("TableName", "Operation", "OldValue", "NewValue", "UpdateDate", "UserName")
           VALUES (TG_TABLE_NAME, 'I', NULL, NEW, now(), USER);
RETURN NEW;
  END IF;
  RETURN NULL;
END;
$$
LANGUAGE 'plpgsql' VOLATILE COST 100;
ALTER FUNCTION fn_log_audit() OWNER TO postgres;