快速业务通道

MySQL数据库中如何解决分组统计的问题

作者 佚名技术 来源 NET编程 浏览 发布时间 2012-03-17
首先准备四张表A、B、C、D,

--------------------------------     
  A      | B  | C   | D     
  a   b   |   a   c   |   a   d   |   d   e     
  1   1   |   1   1   |   1   A   |   A   1     
  2   2   |   1   3   |   2   B   |   B   2     
  3   4   |   1   4   |   3   C   |   C   3     
  4   6   |   2   1   |   4   D   |   D   4     
  --------------------------------

下面我们需要用一条sql语句将A表所有的列,B表对与A表a字段相关联的列求count,通过C表,将D表与A表关联起来,得到的结果如下:

1   1   3   1     
  2   2   1   2     
  3   4   0   3     
  4   6   0   4

MySQL语句解决:

select A.a,A.b,IFNULL(c,0) as c,D.a 
from (select 1 as a,2 as b union all
select 2 as a,2 as b union all
select 3 as a,4 as b union all
select 4 as a,6 as b) as A 
left outer join     
(select a,count(a) as c from(
select 1 as a,3 as c union all
select 1 as a,3 as c union all
select 1 as a,3 as c union all
select 2 as a,3 as c ) B group by a) as B
on A.a=B.a 
join 
(select 1 as a,''A'' as d union all
select 2 as a,''B'' as d union all
select 3 as a,''C'' as d union all
select 4 as a,''D'' as d ) as C 
on A.a=C.a 
join(select 1 as a,''A'' as d union all
select 2 as a,''B'' as d union all
select 3 as a,''C'' as d union all
select 4 as a,''D'' as d ) as D
on D.d=C.d

凌众科技专业提供服务器租用、服务器托管、企业邮局、虚拟主机等服务,公司网站:http://www.lingzhong.cn 为了给广大客户了解更多的技术信息,本技术文章收集来源于网络,凌众科技尊重文章作者的版权,如果有涉及你的版权有必要删除你的文章,请和我们联系。以上信息与文章正文是不可分割的一部分,如果您要转载本文章,请保留以上信息,谢谢!

分享到: 更多

Copyright ©1999-2011 厦门凌众科技有限公司 厦门优通互联科技开发有限公司 All rights reserved

地址(ADD):厦门软件园二期望海路63号701E(东南融通旁) 邮编(ZIP):361008

电话:0592-5908028 传真:0592-5908039 咨询信箱:web@lingzhong.cn 咨询OICQ:173723134

《中华人民共和国增值电信业务经营许可证》闽B2-20100024  ICP备案:闽ICP备05037997号