FIND_IN_SET group_concat 函数

SELECT group_concat(b.itemcontent) FROM
(
SELECT cas.caseId, cas.OVERDUEREASON from d_caseInfo cas where cas.OVERDUEREASON is not null limit 10
) a
left join m_code2 b on FIND_IN_SET(b.itemvalue, a.OVERDUEREASON)
GROUP BY a.caseId