Question

嗨，大家好我想根据条件跟踪条件运行此查询。如果参数日期小于01/01/16，它应该运行第一个CTE，否则运行第二个CTE谢谢

DECLARE @Date AS DATET
SET @Date = '2015-10-31'

;WITH OLDVTE AS (SELECT       
SalesID,
City,
Amount,
SalesDate
FROM INFO.SALESOLD

 ),
NEWVTE AS (   
SalesID,
City,
Amount,
SalesDate
FROM INFO.SALESNEW
 )

SELECT 
CASE WHEN GETDATE() <= @Date THEN 
(SELECT * FROM OLDVTE)
ELSE
(SELECT * FROM NEWVTE)
END AS DD

Answer 1

您可以尝试这样的事情：

DECLARE @Date AS DATE = {d'2015-10-31'}
DECLARE @CurrentDateTime DATETIME = GETDATE();

SELECT       
    SalesID,
    City,
    Amount,
    SalesDate
FROM INFO.SALESOLD
WHERE @CurrentDateTime <= @Date

UNION ALL

SELECT   
    SalesID,
    City,
    Amount,
    SalesDate
FROM INFO.SALESNEW
WHERE @CurrentDateTime > @Date

UNION ALL会将两个结果合二为一。但实际上只有一个选择返回行...

提示

我实际上怀疑，您针对GETDATE()的过滤器会按预期运行...

Answer 2

您可以尝试使用IF ELSE，如下所示。

DECLARE @Date AS DATETIME
SET @Date = '2015-10-31'

If GETDATE() <= @Date--will this clause work..
select * FROM INFO.SALESOLD
Else
select * FROM INFO.SALEnew

如果两个表包含任何公共字段并通过日期

，您也可以加入这两个表

基于给定条件运行查询

2 个答案:

提示