Question

I’ve got a couple of Linq to SQL entities which are causing me problems:

[Table(Name = "ViewName")]
[InheritanceMapping(Code = false, Type = typeof(Entity1), IsDefault = true)]
[InheritanceMapping(Code = true, Type = typeof(Entity2))]
public class Entity1
{
[Column(AutoSync = AutoSync.OnInsert, DbType = "uniqueidentifier NOT NULL", IsPrimaryKey = true, IsDbGenerated = true)]
    public Guid Bssid { get; set; }
    // other properties
[Column(AutoSync= AutoSync.OnInsert ,DbType = "Int NOT NULL IDENTITY", IsDbGenerated = true)]
    public int NewSslid { get; set; } 

}

public class Entity2 : Entity1
{
    public Entity2()
    {
        Discriminator = true;
        _options  = new EntitySet<Entity3>();
    }
}

The entities are using an updatable view rather than a database table as there are about 150 fields spread across two tables. The view runs with all CRUD functions working as they should, but I get the following error when trying to Insert either entity type to the database:

System.InvalidOperationException : Member AutoSync failure. For members to be Auto-Synced after insert, the type must either have an auto-generated identity, or a key that is not modified by the database after insert.

The DB table for Entity1 uses a PK and a separate field (NewSslid) as the identity – which in turn is used as the PK on Entity2 field.

Can anyone point me in the right direction to getting this error sorted?

Answer 1

By altering Entity1:

public class Entity1
{
    public Entity1()
    {
        Guid = System.Guid.NewGuid();
    }

    [Column(IsDbGenerated = true)]
    public Guid Bssid { get; set; }
    [Column(IsPrimaryKey = true, IsDbGenerated = false, Name = "Guid")]
    public Guid? Guid { get; set; }
    // other properties
    [Column(AutoSync = AutoSync.OnInsert , DbType = "Int NOT NULL IDENTITY", IsDbGenerated = true)]
    public int NewSslid { get; set; }

 }

And adding the ‘Guid’ column to the Entity1 table with a default value of newid()