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)
