选择基于特定条件

Question

行我有一个这样的表：

CustID  VisitTime 
1   2012-12-31 11:59 
1   2013-1-1 00:00 
1   2013-1-1 00:05 
2   2013-1-1 00:20 
2   2013-1-1 10:00 
3   2013-1-1 11:40 

现在，我要选择那些新的客户，其访问该网站从Jan 1st 12:00AM到Jan 31st 11:59pm。

例如：cust ID 1也访问Dec，因此cust ID 1不应被选中。应该只选择2和3。

如何使用t-sql合并此逻辑？

Answer 1

SELECT DISTINCT CUSTID 
FROM T as T1 
WHERE VisitTime between '2013-01-01 00:00' AND '2013-01-31 23:59' 
AND NOT EXISTS (SELECT T.CustID FROM T 
         WHERE T.CustId=T1.CustId and VisitTime < '2013-01-01') 

Answer 2

SELECt t.CustID 
FROM Table1 t 
GROUP BY t.CustID 
HAVING MIN(VisitTime) >='01/01/2013 00:00:00' AND MIN(VisitTime) < '02/01/2013 00:00:00' 
--same test on MAX(vistTime) if needed 

SqlFiddle