在自动递增字段上设置自定义标识值

SET Identity_Insert TableName ON

public partial class EntityClassName : global::System.Data.Objects.DataClasses.EntityObject, IEntity
{
    partial void InitializeFields();

    Int64 IEntity.IdentityColumn
    {
        get { return IdentityColumn; }
        set { //some code for an incrementer 
              //and the ability to set manually 
              //if value provide is not null
            }
    }

}