這兩天項目裡出了一個問題，mysql LIMIT使用後報錯。
需求是這樣的，我有3張表，infor信息表，mconfig物料配置表，maaply物料申請表，要求是讀出申請表中哪些人申請哪些物料
於是，首先這樣寫：
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
) www.jbxue.com
結果報錯了
當時沒注意報的什麼錯誤，只是看到LIMIT什麼的錯誤，於是修改以下代碼：
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>
這樣沒有報錯，莫離以為OK了，但是運行後發現，數據有問題
和單純的讀出申請表的內容不一樣，才發現LIMIT的位置放錯了，於是又把LIMIT發在IN裡，結果報錯如下
This version of MySQL doesn't yet support ‘LIMIT & IN/ALL/ANY/SOME subquery'
細看才知道，IN裡不支持LIMIT。那怎麼辦呢？www.jbxue.com
於是度娘後得知，在IN裡再使用一張臨時表，把需要的內容先查出來，
修改後：
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`
)
運行後，問題解決!
