sqlxa0查询xa03个月内

DATEDIFF 函数 [日期和时间]格式：DATEDIFF ( date-part, date-expression-1, date-expression-2 );功能：
返回两个日期之间的间隔，即date-expression-2 减 date-expression-1的以date-part为单位的值。例子：SELECT datediff( month, '1999/07/19', '1999/08/23' );//返回 1
SELECT datediff( day, '1999/07/19 00:00', '1999/07/23 23:59' );//返回 4----------------------------------------------------------------------------------------------------修改：select * from OrderList where UserName='"&Session("UserName")&"' and datediff(Month,BuyTime,getdate(),Now) <=3"