SQL通過分組行

Question

假設我有一個表像這樣獲得共同的價值觀：

| uid | group_id | 
----------------- 
| 1 |  1 | 
| 1 |  2 | 
| 1 |  3 | 
| 1 |  4 | 
| 2 |  1 | 
| 2 |  2 | 
| 2 |  3 | 
| 3 |  1 | 
| 3 |  2 | 
| 3 |  4 | 
... 

我怎樣才能得到一組共用的group_ids一些一套uids。

例如，
爲UID 1,2：常見的group_ids是1,2,3
爲UID 1,2,3：常見的group_ids是1和2

Answer 1

假設每個group_ID是獨特每uid，（否則你需要使用distinct）

SELECT group_ID 
FROM tableName 
WHERE uid IN (1,2,3) 
GROUP BY group_ID 
HAVING COUNT(*) = 3 

• SQLFiddle Demo (includes two queries)