SQL跨表更新

[一篮饭特稀原创，转载请注明出自http://www.cnblogs.com/wanghafan/p/4384039.html] 

前提：两张表要更新的字段、关联字段结构一致

更新库：FJPDI_TZGL

提取库：FJPDI_TZGL_29

表：DataChangesTempT

更新字段：REASON

关联字段：IID

目标：把FJPDI_TZGL_29中DataChangesTempT的REASON字段更新到FJPDI_TZGL_中DataChangesTempT的REASON字段

查询语句：

SELECT IID,REASON FROM FJPDI_TZGL.dbo.DataChangesTempT
SELECT IID,REASON FROM FJPDI_TZGL_29.dbo.DataChangesTempT

更新语句：

UPDATE FJPDI_TZGL.dbo.DataChangesTempT 
SET REASON= d.REASON
FROM  FJPDI_TZGL_29.dbo.DataChangesTempT d 
WHERE FJPDI_TZGL.dbo.DataChangesTempT.IID=d.IID