按COUNT（*）過濾？

Question

是否可以對結果進行分組，然後根據組中有多少行進行過濾？

事情是這樣的：

SELECT * FROM mytable WHERE COUNT(*) > 1 GROUP BY name 

Answer 1

你要使用具有對聚合函數進行篩選。

SELECT name, COUNT(*) 
    FROM mytable 
    GROUP BY name 
    HAVING COUNT(*) > 1 

Answer 2

您需要使用HAVING

SELECT * FROM mytable GROUP BY name HAVING COUNT(*) > 1 

雖然SELECT *不會使當你分組太大的意義。我認爲它只是一個在你的查詢爲例

Answer 3

用途：

SELECT * FROM mytable GROUP BY name having COUNT(*) > 1 

Answer 4

你想要一個HAVING子句。

SELECT * 
FROM mytable 
GROUP BY name 
HAVING COUNT(*) > 1