无法附加已存在的实体

Question

我试图通过Linq更新代码,但我收到此错误:

无法附加已存在的实体.

C#代码在这里:

var con = (from c in cmsContentTable where c.ContentName == contentId
           select c).FirstOrDefault();  
cmsContentTable.Attach(con);  
con.ContentData = "New Value";  
cmsContentTable.Context.SubmitChanges();

Answer 1

您不需要附加实体,它已经属于上下文.

var con = (from c in cmsContentTable where c.ContentName == contentId select c).FirstOrDefault();
con.ContentData = "New Value";
cmsContentTable.Context.SubmitChanges();