Porting project from Entity Framework 6 (.NET 4.0) to Entity Framework Core (.NET Core 2.0)

[bairog]

Hello.
For today we have project which uses Entity Framework 6 Code-First approach (.NET 4.0).
I'm trying to port this project to Entity Framework Core (.NET Core 2.0) and I faced several problems:

1. In EF 6 I used configuration with DbConfigurationTypeAttribute which is missing from EF Core:

   Code: Select all

   [DbConfigurationType(typeof(Devart.Data.SQLite.Entity.SQLiteEntityProviderServicesConfiguration))]

2. In EF 6 to read user_version I used the access to ObjectContext which is missing from EF Core:

   Code: Select all

   var objContext = ((IObjectContextAdapter)MyDbContext).ObjectContext;
   var user_version = objContext .ExecuteStoreQuery<long>("PRAGMA [main].user_version").FirstOrDefault();

3. In EF 6 I programmatically added data provider using SQLiteConnectionInfo.InvariantName which is missing from Devart.Data.SQLite.Entity.EFCore:

   Code: Select all

   try
   {
   var dataTable = (ConfigurationManager.GetSection("system.data") as DataSet).Tables[0];
   
   //DbProviderFactory is already installed - need to delete it before
   foreach (DataRow row in dataTable.Rows)
     if (row[2].Equals(SQLiteConnectionInfo.InvariantName))
     {
         row.Delete();
         row.AcceptChanges();
         break;
      }
   
      //Add Data Provider
      dataTable.Rows.Add("dotConnect for SQLite",
      "dotConnect for SQLite",
      SQLiteConnectionInfo.InvariantName,
      "Devart.Data.SQLite.SQLiteProviderFactory, Devart.Data.SQLite, Culture=neutral, PublicKeyToken=09af7300eec23701");
   }
   catch (Exception ex)
   {
        throw new Exception("DataProvider add error", ex);
   }

4. In EF 6 I used SQLiteEntityMigrationSqlGenerator which is missing from Devart.Data.SQLite.Entity.EFCore:

   Code: Select all

   internal sealed class MyDbContextMigrationConfiguration : DbMigrationsConfiguration<MyDbContext>
   {
        public MyDbContextMigrationConfiguration()
        {
             AutomaticMigrationsEnabled = true;
             AutomaticMigrationDataLossAllowed = false;
             SetSqlGenerator(SQLiteConnectionInfo.InvariantName, new SQLiteEntityMigrationSqlGenerator());
         }
   }
   ........................................................
   //migration settings
   Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyDbContext, MyContextMigrationConfiguration>());

So what are the workarounds for that problems?
Thank you in advance.

[Shalex]

We recommend you to recreate EF Core model from scratch using Entity Developer instead of migrating EF6 to EF Core.


Answers to your questions are:

1. In EF 6 I used configuration with DbConfigurationTypeAttribute which is missing from EF Core:

Code: Select all

[DbConfigurationType(typeof(Devart.Data.SQLite.Entity.SQLiteEntityProviderServicesConfiguration))]

EF Core picks up our provider via the optionsBuilder.UseSQLite extension method.

2. In EF 6 to read user_version I used the access to ObjectContext which is missing from EF Core:

Code: Select all

var objContext = ((IObjectContextAdapter)MyDbContext).ObjectContext;
var user_version = objContext .ExecuteStoreQuery<long>("PRAGMA [main].user_version").FirstOrDefault();

You can get an ADO.NET connection via context.Database.GetSQLiteConnection() and run your command via SQLiteCommand.ExecuteScalar().

3. In EF 6 I programmatically added data provider using SQLiteConnectionInfo.InvariantName which is missing from Devart.Data.SQLite.Entity.EFCore:

Code: Select all

try
{
var dataTable = (ConfigurationManager.GetSection("system.data") as DataSet).Tables[0];

//DbProviderFactory is already installed - need to delete it before
foreach (DataRow row in dataTable.Rows)
  if (row[2].Equals(SQLiteConnectionInfo.InvariantName))
  {
      row.Delete();
      row.AcceptChanges();
      break;
   }

   //Add Data Provider
   dataTable.Rows.Add("dotConnect for SQLite",
   "dotConnect for SQLite",
   SQLiteConnectionInfo.InvariantName,
   "Devart.Data.SQLite.SQLiteProviderFactory, Devart.Data.SQLite, Culture=neutral, PublicKeyToken=09af7300eec23701");
}
catch (Exception ex)
{
     throw new Exception("DataProvider add error", ex);
}

Please specify "Devart.Data.SQLite" explicitly.

4. In EF 6 I used SQLiteEntityMigrationSqlGenerator which is missing from Devart.Data.SQLite.Entity.EFCore:

Code: Select all

internal sealed class MyDbContextMigrationConfiguration : DbMigrationsConfiguration<MyDbContext>
{
     public MyDbContextMigrationConfiguration()
     {
          AutomaticMigrationsEnabled = true;
          AutomaticMigrationDataLossAllowed = false;
          SetSqlGenerator(SQLiteConnectionInfo.InvariantName, new SQLiteEntityMigrationSqlGenerator());
      }
}
........................................................
//migration settings
Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyDbContext, MyContextMigrationConfiguration>());

MigrateDatabaseToLatestVersion is no longer available in EF6, you should use context.Database.Migrate().

[bairog]

We recommend you to recreate EF Core model from scratch using Entity Developer instead of migrating EF6 to EF Core.

What do you mean by that phrase? I use Code-First approach - so my model is a set if POCO classes..

[Shalex]

If you didn't use *.edml, there is no need to use *.efml.