我目前正在尝试将另一个表中的列连接到现有表,并将其返回到MVC 4中的视图
var q = from accCo in db.AccControls
join accCom in db.AccCompanies
on new { accCo.ControlCode } equals
new { ControlCode = accCom.Code }
where accCo.ControlCode == Request.QueryString["ControlCode"]
orderby accCom.Code
select new Combined{ AccControls = accCo, AccCompoanies = accCom };
return View(q);
但是我遇到了以上错误
最佳答案
如果您加入的任何列可为空,则需要将其更改为.Value
on new { accCo.ControlCode } equals
new { ControlCode = accCom.Code.Value }
或者你可以用这个
var q = from accCo in db.AccControls
join accCom in db.AccCompanies
where accCom.Code != null
on new { accCo.ControlCode } equals
new { ControlCode = accCom.Code }
where accCo.ControlCode == Request.QueryString["ControlCode"]
orderby accCom.Code
select new Combined{ AccControls = accCo, AccCompoanies = accCom };