Linq to SQL: Why am I getting IDENTITY_INSERT errors?

Question

I\'m using Linq to SQL. I have a DataContext against which I am .SubmitChanges()\'ing. There is an error inserting the identity field:

Cannot insert explicit value for         


        

Answer 1

I was having the exact same problem.

My solution was to manually make the identity INT column into a nullable INT? column in the DBML designer, not in the actual table of the DB of course. Also set the DbType to NULL instead of NOT NULL. Like so:

[Column(Storage="_TestID", AutoSync=AutoSync.OnInsert, DbType="Int NULL IDENTITY", IsPrimaryKey=true, IsDbGenerated=true)] 
public int? TestID

This works with all DB operations. When inserting simply set the identity column to NULL rather than to 0.