作者tref (MFDA)
看板Web_Design
标题Re: [问题] mysql count/count 怎麽做??
时间Fri Nov 10 22:45:36 2006
※ 引述《cy0824 (chuchutrainz)》之铭言：
: 请问一下,我有两个queries
: Table:A
: field:a,b,c
: $query1= "SELECT a, count(b) from A where a='$a' group by a";
: $query2= "select a, count(b) from A where a='$a' and c='1' group by a";
: 我想有一个新的query是query2 除以 query1然後取百分比..然後四舍五入,,请问怎麽做呢??
: 谢谢
竟然没人回，那就让在下赚点p币好了(赌光光..> <)
你要的结果，用个sql应该就可以解决
select t1.a,round(t2.cc/count(t1.b)*100,0) from A t1
inner join
(select a, count(b) as cc from A where a='$a' and c='1' group by a) t2 on t1.a=t2.a
where t1.a='$a' group by a
上面的sql可能还要依你的资料库来修改
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