FIND_IN_SET(str,strlist)

返回1到N范围内的值，如果字符串str在字符串列表STR列由N-子字符串。

SQL> SELECT FIND_IN_SET('b','a,b,c,d');
+---------------------------------------------------------+
| SELECT FIND_IN_SET('b','a,b,c,d')                       |
+---------------------------------------------------------+
| 2                                                       |
+---------------------------------------------------------+
1 row in set (0.00 sec)