sql中如何查詢出訪問量最多的月份

 有表 PageView

ViewTime (列名)                                               
------------------------------------------------------
2007-08-18 13:30:24
2007-08-18 13:30:24
2007-08-18 13:30:45
2007-08-18 13:30:45
2007-08-18 13:30:59
2007-08-18 13:30:59
2007-08-18 16:22:55
2007-08-20 16:32:25
2007-08-21 11:02:13

1。如何得出2007年8月?

解：

Select Top 1 ViewTime
  From (Select Convert(varchar(7),ViewTime,120) As ViewTime
              ,Count(Convert(varchar(7),ViewTime,120)) As viewcount
          From PageView
         Group by convert(varchar(7),ViewTime,120)) As maxviews
 Order By viewcount DESC

結果：2007-08

2。如何得出2007年8月18日?

解：

Select Top 1 ViewTime
  From (Select Convert(varchar(10),ViewTime,120) As ViewTime
              ,Count(Convert(varchar(10),ViewTime,120)) As viewcount
          From PageView
         Group by convert(varchar(10),ViewTime,120)) As maxviews
 Order By viewcount DESC

結果：2007-08-18

 

呵呵，看到區別了嗎？主要是Convert(varchar(n), ViewTime, 120) 中的原因。。。。