I have to update a field with a value which is returned by a join of 3 tables.
Example:
select im.itemid ,im.sku as iSku ,gm.SKU as GSKU
Try like this...
Update t1.Column1 = value from tbltemp as t1 inner join tblUser as t2 on t2.ID = t1.UserID where t1.[column1]=value and t2.[Column1] = value;