试试这个:
SELECT a.* FROM A aLEFT JOIN B b ON b.id = a.bIdWHERE exists (SELECT c.id FROM C cWHERE b.cId =c.id and name LIKE CONCAT('%', '123', '%'));
还要检查索引是否合理哦！
列ID name 是否建立了索引
请采纳！
