c# - Invalid operation exception in context.SaveChanges() with oracle entity framwork 5 -

i use oracle ef 5.0 provider. oracle 11g database. here database schema:

table has id primary key. each table in database there trigger, fires on insert new record , ef primary key after insert sequence. sequences created each table. in edmx file each id column has storegeneratedpattern="identity" attribute set.

my code is:

 using (var context = new entities())  {     var title = new title     {         title_number = 4000001,         is_draft = "n",          registry_date = datetime.now     };      var titlename = new title_name     {         name = "title name"     };     title.title_name.add(titlename);     context.set<title>().add(title);     context.savechanges();  } 

when context.savechanges() executed, there exception thrown:

the changes database committed successfully, error occurred while updating object context. objectcontext might in inconsistent state. inner exception message: acceptchanges cannot continue because object's key values conflict object in objectstatemanager. make sure key values unique before calling acceptchanges.

but changes saved in database correctly. , title object has correct id title , title_name. can do? or wrong?

opps. remove inheritance edmx , error goes away!....

but project build in inheritance!!!

ops. ms sql same scheme gives exception too.

from here: https://entityframework.codeplex.com/workitem/2515
ef team triage: because have identity configured tpc mapping. because 2 types mapped separate tables, duplicate ids generated since database doesn't know generate unique values between 2 tables. 1 way around modify tables have 1 generate odd numbers , other generate numbers. workaround this.

we create interface shared properties entities , remove inheritance edmx file.
i.e.

public interface ihistoricalentity {     int id { get; set; }     int entity_id { get; set; }     datetime create_date { get; set; }     datetime delete_date { get; set; }     int creator { get; set; } } 

in partial file title.cs

public partial class title : ihistoricalentity { } 

and can use generic version entities in our project.