sql當datetime列爲null或空時投射

Question

如果regdate列不爲null或爲空，且返回的日期早於2 years.if它爲空，我喜歡將regdate插入爲1900-01-01，

id name regdate 
555 bob  24/06/2013 00:00:00 
556 tom  24/07/2013 00:00:00 
557 jack 24/10/2008 00:00:00 
558 susan 24/11/2009 00:00:00 
559 emily 
560 Mert  


SELECT *, CAST(idate AS DATETIME) AS finalDate 
    INTO #tempFinal 
    FROM #tempA 
    WHERE CAST(idate AS DATETIME) < DATEADD(YEAR, -2, GETDATE()) 
    OR idate IS NULL OR idate = '' 

Answer 1

你應該能夠做到這一點：

CAST(ISNULL(Idate, '1900-01-01') AS DATE)