Question

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

我正在使用SQL Server 2008

这是我的尝试，但我在代码之外会遇到语法错误。

有更好的方法吗？

使用大小写正确的语法是什么？

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，您不能通过日期参数限制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......您可以通过将其视为低端或高端日期来处理NULL：

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')

修改

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胜过另一种方法......

Answer 2

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

Answer 3

请注意，以下查询应避免使用，并且应提及具体的列名。

declare @StartDate datetime;    
declare @EndDate datetime;
SET @EndDate = GETDATE();
SET @StartDate = DATEADD(year, -2, GETDATE()); 

Declare @SQL Varchar(1000)

Set @SQL = 'select ColumnName
from ArCustomer
where CAST(Customer as int) > 1000
AND'
if(@StartDate IS NOT NULL AND @EndDate IS NOT NULL)
Begin
    Set @SQL = @SQL + ' ArCustomer.DateLastSale BETWEEN ''' + Convert(varchar, @StartDate) + 
    ''' AND ''' + Convert(varchar, @EndDate) + ''''
End
else if(@StartDate IS NULL AND @EndDate IS NOT NULL)
Begin   
        Set @SQL = @SQL + ' ArCustomer.DateLastSale < ''' + Convert(varchar, @EndDate) + ''''
End
else
    Set @SQL = @SQL + ' ArCustomer.DateLastSale > ''' + Convert(varchar, @StartDate) + ''''        


exec(@SQL)

考虑所有情况。

SQL日期选择为NULL，After，Before，Between

3 个答案: