MySql依据多个ID查询

CREATE TABLE TBL_USER_DTL
(
USER_ID VARCHAR(32),
USER_NAME VARCHAR(50)
);

CREATE TABLE TBL_USER_INF
(
TU_ID VARCHAR(32),
USER_IDS VARCHAR(2000)
);

DELIMITER $$

CREATE FUNCTION TEST_MY_SQL(STRS VARCHAR(2000)) RETURNS VARCHAR(2000)
BEGIN
DECLARE CNT_NAMES VARCHAR(2000) DEFAULT '';
DECLARE CUR_NAME VARCHAR(50) DEFAULT '';
DECLARE EMPID VARCHAR(32) DEFAULT '';
DECLARE LAST_ID VARCHAR(32) DEFAULT '';

IF LOCATE(',', STRS) <= 0 THEN
#单个ID取出信息
SELECT USER_NAME INTO CNT_NAMES FROMTBL_USER_DTL WHERE USER_ID = STRS;
ELSE
#取出前面的ID信息
WHILE LOCATE(',', STRS) > 0 DO
SELECT SUBSTR(STRS, 1, LOCATE(',', STRS) - 1) INTO EMPID;
SELECT USER_NAME INTO CUR_NAME FROMTBL_USER_DTL WHERE USER_ID = EMPID;
SELECT SUBSTR(STRS, LOCATE(',', STRS) + 1, CHAR_LENGTH(STRS)) INTO STRS;
SET CNT_NAMES = CONCAT(CNT_NAMES,CUR_NAME,',');
SET CUR_NAME = '';
#取出最后一个ID
SELECT SUBSTR(STRS, LOCATE(',', STRS) + 1, CHAR_LENGTH(STRS)) INTO LAST_ID;
END WHILE;
SELECT USER_NAME INTO CUR_NAME FROMTBL_USER_DTL WHERE USER_ID = LAST_ID;
SET CNT_NAMES = CONCAT(CNT_NAMES,CUR_NAME);
END IF;
RETURN CNT_NAMES;
END$$

DELIMITER ;

例：

查询结果如下图所示

目前该函数不能泛用，且表名需要更改等已知问题。由于对MySql了解不多，目前只能做到这个程度了。欢迎指正，谢谢。