饮食贵在节,读书贵在精,锻炼贵在恒,节饮食养胃,多读书养胆,喜运动延生!人生需要有目标,有追求,然有所以。
这两天项目里出了一个问题,LIMIT使用后报错。 需求是这样的,我有3张表,infor信息表,mconfig物料配置表,maaply物料申请表,要求是读出申请表中哪些人申请哪些物料 于是我先是这样写的:
SELECT infor.name,infor.phone,infor.add,
mconfig.mname,mapply.acount,from_unixtime(mapply.atime,'%Y-%m-%d') as 'atime'
FROM mapply right JOIN infor ON mapply.uid = infor.uid inner JOIN mconfig ON mapply.mid = mconfig.mid
WHERE mapply.aid
IN (
SELECT aid
FROM `mapply` where state = $state
ORDER BY `atime` , `uid` DESC
LIMIT 0,10
)
结果报错了 当时没注意报的什么错误,只是看到LIMIT什么的错误,于是改了下代码
SELECT infor.name,infor.phone,infor.add,
mconfig.mname,mapply.acount,from_unixtime(mapply.atime,'%Y-%m-%d') as 'atime'
FROM mapply right JOIN infor ON mapply.uid = infor.uid inner JOIN mconfig ON mapply.mid = mconfig.mid
WHERE mapply.aid
IN (
SELECT aid
FROM `mapply` where state = $state
ORDER BY `atime` , `uid` DESC
)
<pre name="code" class="sql">LIMIT 0,10</pre>
这样没有报错,莫离以为OK了,但是运行后发现,数据有问题 和单纯的读出申请表的内容不一样,才发现LIMIT的位置放错了,于是又把LIMIT发在IN里,结果报错如下 This version of MySQL doesn't yet support ‘LIMIT & IN/ALL/ANY/SOME subquery' 细看才知道,IN里不支持LIMIT。那怎么办呢? 于是度娘后得知,在IN里再使用一张临时表,把需要的内容先查出来, 修改后代码如下:
SELECT infor.name,infor.phone,infor.add,
mconfig.mname,mapply.acount,from_unixtime(mapply.atime,'%Y-%m-%d') as 'atime'
FROM mapply right JOIN infor ON mapply.uid = infor.uid inner JOIN mconfig ON mapply.mid = mconfig.mid
WHERE mapply.aid
IN (
SELECT aid
FROM (SELECT `aid` FROM `mapply` where state = $state
ORDER BY `atime` , `uid` DESC
LIMIT 0,10)AS `tp`
)
运行后,问题解决~~~
本文Mysql子查询IN中如何使用LIMIT应用示例到此结束。此刻不玩命,将来命玩你。小编再次感谢大家对我们的支持!