mysql 按指定字符拆分字符串

SQL语句：

SET @str = '7654,7698,7782,7788';
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(@str, ',', help_topic_id + 1), ',', - 1) AS num
FROM mysql.help_topic
WHERE help_topic_id < LENGTH(@str) - LENGTH(REPLACE (@str, ',', '')) + 1

封装成存储过程：

/*
 * 名称：按指定字符拆分字符串
 * 输入参数，str，需拆分的字符串
 * 输入参数，splitChar，用于分隔的字符
 */
DROP PROCEDURE IF EXISTS proc_common_split;
CREATE PROCEDURE proc_common_split 
(
    -- 需拆分的字符串
    str LONGTEXT,
    -- 用于分隔的字符
    splitChar CHAR(1)
)
BEGIN
    SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(str, splitChar, help_topic_id + 1), splitChar, - 1) AS Result
    FROM mysql.help_topic
    WHERE help_topic_id < LENGTH(str) - LENGTH(REPLACE (str, splitChar, '')) + 1;
END;

/*

    输入参数，str，需拆分的字符串
    输入参数，splitChar，用于分隔的字符
 
    CALL proc_common_split('1,2,3', ',');

*/