复杂选择比较

Question

嘿家伙我有两个表T1和T2，T1有一个叫做时间的柱面，T2有两个柱面日期和时间。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 

我需要写一个选择返回2013年10月1日，因为这一天的比赛中与ALL T1领域倍。这可能吗？

Answer 1

只要你有这将工作在T1

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

或多个 “通用”，但少高性能的3个值：

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