如何連接兩個選擇在同一個表

我有一個像如何連接兩個選擇在同一個表

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

兩個選擇語句是有沒有辦法在一個查詢兩種說法結合起來？結果長度不同，因此需要在第二個結果集中插入一些0。

非常感謝所有幫助

最好的問候，西蒙娜

來源

2013-02-15 user299791

您應該使用能夠在一個單一的查詢來獲取這樣的：

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

來源

2013-02-15 22:29:42 Taryn

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

這是你在找什麼？

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

來源

2013-02-15 22:28:23 sgeddes

你可以嘗試聯合所有聲明？

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 
    )

來源

2013-02-15 22:30:05 Tucker

如何連接兩個選擇在同一個表

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