Entity Framework 6 wrong reference when update model from database

Question

After uptade Entity framework any version to Entity Framework in existing project in MYDATABASE.edmx When I update model from database Visual studio generates using lines such as

  using System.Data.Objects;   
  using System.Data.Objects.DataClasses;

but Here is should be:

using System.Data.Entity.Core.Objects;

Answer 1

1.Open MYDATABASE.Context.tt (Your code generation template) (Under the MYDATABASE.edmx)

2.Find invalid references like this

{
#>
using System.Data.Objects;   
using System.Data.Objects.DataClasses;
using System.Linq;
<#
}

3.Replace like this

{
#>
using System.Data.Entity.Core.Objects;
using System.Linq;
<#
}