SQL Server 2005 将变量设置为选择查询的结果

Question

如何在不使用存储过程的情况下将变量设置为选择查询的结果？

<小时/>

我想做一些类似的事情: OOdate 日期时间

SET OOdate = Select OO.Date 
FROM OLAP.OutageHours as OO
WHERE OO.OutageID = 1

然后我想在此查询中使用 OOdate:

SELECT COUNT(FF.HALID) from Outages.FaultsInOutages as OFIO
INNER join Faults.Faults as FF ON FF.HALID = OFIO.HALID
WHERE CONVERT(VARCHAR(10),OO.Date,126) = CONVERT(VARCHAR(10),FF.FaultDate,126)) 
AND
OFIO.OutageID = 1

Answer 1

你可以使用类似的东西

SET @cnt = (SELECT COUNT(*) FROM User)

或

SELECT @cnt = (COUNT(*) FROM User)

为此，SELECT 必须返回单个列和单个结果，并且 SELECT 语句必须位于括号中。

编辑:你尝试过这样的事情吗？

DECLARE @OOdate DATETIME

SET @OOdate = Select OO.Date from OLAP.OutageHours as OO where OO.OutageID = 1

Select COUNT(FF.HALID) 
from Outages.FaultsInOutages as OFIO 
inner join Faults.Faults as FF 
    ON FF.HALID = OFIO.HALID 
WHERE @OODate = FF.FaultDate
    AND OFIO.OutageID = 1