Question

SELECT * FROM TABLE 
 WHERE  YEAR(MDTFlgtStart)=YEAR(GETDATE()) AND MONTH(MDTFlgtStart)=MONTH(GETDATE())

以上代码将当前年份和月份与列年份和月份进行比较。但我们是否有机会给年= 2012月= 3 或年= 2011月= 5

Answer 1

您可以声明变量：

DECLARE @YEAR AS INT
DECLARE @MONTH AS INT

SET @YEAR = 2012
SET @MONTH = 3

SELECT * 
FROM TABLE 
WHERE  YEAR(MDTFlgtStart)=@YEAR AND MONTH(MDTFlgtStart)=@MONTH

您可以将上述内容包含在可重用性的程序中....

Answer 2

您可以使用这些值的参数。作为奖励，avoiding functions against the column will help assist a seek if an index exists on the column（当然SELECT * means it will likely end up as a full scan anyway, or a range scan and a bunch of lookups）...

-- these would be input parameters for your stored procedure
DECLARE @y INT = 2011, @m INT = 5;


-- now have a date variable:
DECLARE @dt DATE = DATEADD(MONTH, @m-1, DATEADD(YEAR, @y-1900, 0));

SELECT ... FROM dbo.tablename
  WHERE MDTFlgtStart >= @dt
    AND MDTFlgtStart < DATEADD(MONTH, 1, @dt);

此外，您应该停止邀请任何将这些列命名为午餐的人，因为我必须假设他们不是很好。

将SQL Server datetime列与年份进行比较？

2 个答案: