Cannot attach an entity that already exists.

Question

i am trying to update code via Linq, but getting this error
Cannot attach an entity that already exists.

C# code is here
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

You don't need to attach the entity, it already belongs to the context.

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