Insert data(string or null, date etc...) with ps, building dynamic sql, excuting with prepare sql

test_insert_data.sql

CREATE TABLE `str_test` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) DEFAULT NULL,
  `ats` text,
  `dor` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

delimiter $$

DROP FUNCTION str_filter $$

CREATE FUNCTION str_filter(in_src TEXT)
RETURNS TEXT DETERMINISTIC
BEGIN
    IF in_src IS NOT NULL THEN
       RETURN CONCAT('''', in_src, '''');
   ELSE
      RETURN 'NULL';
   END IF;    
END $$


CALL test_insert_data_null('guohai','text long long', '2011-07-11 13:33:21', @last_id, @no, @msg) $$

SELECT @last_id, @no, @msg $$

DROP PROCEDURE IF EXISTS test_insert_data_null $$

CREATE PROCEDURE test_insert_data_null(in_name VARCHAR(20), in_ats TEXT, in_dor VARCHAR(20), OUT last_id BIGINT, OUT no INT, OUT msg VARCHAR(50))
BEGIN
	DECLARE INSERT_SQL VARCHAR(200);

	SET @MYQUERY := CONCAT('INSERT INTO str_test(name, ats, dor) VALUES(', str_filter(in_name), ',', str_filter(in_ats), ',', 'str_to_date(''', in_dor, ''',', '''%Y-%m-%d %H:%i:%s''))');
	PREPARE INSERT_SQL FROM @MYQUERY;
	EXECUTE INSERT_SQL;
	DEALLOCATE PREPARE INSERT_SQL;

	SELECT LAST_INSERT_ID() INTO last_id;
END $$

-- of course the efficiency of the method is unsatisfied, but some sometimes we really really hava to do this