複雜選擇比較

Question

嘿傢伙我有兩個表T1和T2，T1有一個叫做時間的柱面，T2有兩個柱面日期和時間。按照方案

T1 
------------------- 
Time 
------------------- 
10:00 
11:00 
12:00 

T2 
------------------- 
Date  | Time 
------------------- 
2013-10-01 | 10:00 
2013-10-01 | 11:00 
2013-10-01 | 12:00 
2013-10-02 | 10:00 
2013-10-02 | 11:00 

我需要寫一個選擇返回2013年10月1日，因爲這一天的比賽中與ALL T1領域倍。這可能嗎？

Answer 1

只要你有這將工作在T1

SELECT T2.Date 
FROM T2 
inner join T1 on T1.Time = T2.Time 
GROUP BY T2.Date 
HAVING COUNT(DISTINCT T1.Time) = 3 

或多個 「通用」，但少高性能的3個值：

SELECT T2.Date 
FROM T2 
INNER JOIN T1 on T1.Time = T2.Time 
GROUP BY T2.Date 
HAVING COUNT(DISTINCT T1.Time) = (select count(distinct Time) from T1); 

SqlFiddle