SQL日期选择为NULL,After,Before,Between

Question

要求:按日期选择After,Before,Between或all if null

我正在使用SQL Server 2008

这是我的尝试,但我在代码之外的语法错误是有效的.

1. 有更好的方法吗？

2. 用例是什么语法正确？

   declare @StartDate datetime;    
   declare @EndDate datetime;
   SET @EndDate = GETDATE();
   SET @StartDate = DATEADD(year, -2, GETDATE()); 
   
   select *
   from ArCustomer
   where CAST(Customer as int) > 1000
   AND
       CASE WHEN @StartDate IS NOT NULL AND @EndDate IS NOT NULL THEN
           ArCustomer.DateLastSale BETWEEN @StartDate AND @EndDate
       WHEN @StartDate IS NULL AND @EndDate IS NOT NULL THEN
           ArCustomer.DateLastSale < @EndDate 
       WHEN @StartDate IS NOT NULL AND @EndDate IS NULL THEN
           ArCustomer.DateLastSale > @StartDate        
   END;
   

Answer 1

或者,您不能通过date参数限制它是否NULL:

SELECT *
FROM ArCustomer ac
WHERE 
    CAST(ac.Customer as int) > 1000
    AND (ac.DateLastSale >= @StartDate OR @StartDate IS NULL)
    AND (ac.DateLastSale <= @EndDate OR @EndDate IS NULL)

或者......您可以NULL将其视为低端或高端日期:

SELECT *
FROM ArCustomer ac
WHERE 
    CAST(ac.Customer as int) > 1000
    AND ac.DateLastSale BETWEEN ISNULL(@StartDate, '1900-01-01') 
        AND ISNULL(@EndDate, '9999-12-31')

编辑:

这两种方法之间的执行计划可能存在差异,因此您可以尝试这两种方法,看看是否有一种方法优于其他方法......