在sql server中的組和計數

Question

我想要一個簡單的查詢來獲得一些輸出。記錄是

ID  Count 
215  1 
215  1 
215  1 
215  1 

輸出必須

ID Count 
215 4 

Answer 1

SELECT ID, COUNT(*) AS Count 
FROM tablename 
GROUP BY ID 

Answer 2

很簡單，

SELECT ID ,COUNT(*) AS CNT 
FROM TABLE_NAME 
GROUP BY ID 

Answer 3

SELECT ID, sum(Count) AS Count 
FROM tablename 
GROUP BY ID