各位大虾,小弟写了一个语句,用于更新各类别的电影数量,分类是2级分类,但是为什么不能用啊……
UPDATE am_class c LEFT JOIN am_movie m ON (c.cid=m.mclass) SET c.cmovienum = (SELECT COUNT(*) FROM am_movie WHERE mclass IN (SELECT cid FROM am_class WHERE cparent=c.cid OR cid=c.cid));
但是如下语句都可以使用
UPDATE am_class c LEFT JOIN am_movie m ON (c.cid=m.mclass) SET c.cmovienum = (SELECT COUNT(*) FROM am_movie WHERE mclass=c.cid);
SELECT COUNT(*) FROM am_movie WHERE mclass IN (SELECT cid FROM am_class WHERE cparent=1 OR cid=1);
是不是表别名在子查询中还有作用域之类的东西呢?如果要改的话,应该怎么更改哦?先在这里猛谢一下了..... 鞠躬360度...
UPDATE am_class c LEFT JOIN am_movie m ON (c.cid=m.mclass) SET c.cmovienum = (SELECT COUNT(*) FROM am_movie WHERE mclass IN (SELECT cid FROM am_class WHERE cparent=c.cid OR cid=c.cid));
但是如下语句都可以使用
UPDATE am_class c LEFT JOIN am_movie m ON (c.cid=m.mclass) SET c.cmovienum = (SELECT COUNT(*) FROM am_movie WHERE mclass=c.cid);
SELECT COUNT(*) FROM am_movie WHERE mclass IN (SELECT cid FROM am_class WHERE cparent=1 OR cid=1);
是不是表别名在子查询中还有作用域之类的东西呢?如果要改的话,应该怎么更改哦?先在这里猛谢一下了..... 鞠躬360度...
UPDATE 多个表只能
UPDATE A,B SET A.。