如何连接两个选择在同一个表

我有一个像如何连接两个选择在同一个表

Select author_id, count(text) from posts group by author_id 

select author_id, count(text) from posts where postcounter =1 group by author_id

两个选择语句是有没有办法在一个查询两种说法结合起来？结果长度不同，因此需要在第二个结果集中插入一些0。

非常感谢所有帮助

最好的问候，西蒙娜

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2013-02-15 user299791

您应该使用能够在一个单一的查询来获取这样的：

Select author_id, 
    count(text) TextCount, 
    count(case when postcounter=1 then text end) PostCount 
from posts 
group by author_id

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2013-02-15 22:29:42 Taryn

非常感谢你，它完美的作品！ Best，Simone – user299791 2013-02-16 13:50:43

这是你在找什么？

select author_id, 
    sum(case when postcounter = 1 then 1 else 0 end) count1, 
    sum(case when postcounter <> 1 then 1 else 0 end) count2, 
    count(text) allcount 
from posts 
group by author_id

来源

2013-02-15 22:28:23 sgeddes

你可以尝试联合所有声明？

SELECT `id`,sum(`count`) FROM (
Select author_id as `id`, count(text) as `count` from posts group by author_id 
UNION ALL 
select author_id as `id`, count(text) as `count` from posts where postcounter =1 group by author_id 
    )

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2013-02-15 22:30:05 Tucker

如何连接两个选择在同一个表

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