Migrating data in an database created with EF code first (devart connector) to EFCore code first (sqlite)

Question

The EFCore documentation is very specific on what to do, to migrated an EF based codebase to EFCore https://learn.microsoft.com/en-us/ef/efcore-and-ef6/porting/ . However, I could not find advice on how to bring the data stored in an sqlite database from EF to EFCore.

Beside the obvious approach to read from the old EF dbcontext and write to the new EFCore context, we are exploring the possiblity to configure EFCore (using the same model classes) to create the same database schema created by EF and then use the EFCore dbcontext to read the data.

Is this approach the recommended way to migrate the data or continue accessing the data from the old schema?

There appear to be multiple differences in the schema created by EF and EFCore troubling me. Some of them might be related to the fact that with EF we used Devart dotConnect Data Provider while with EFCore we use the database provider that comes with the EFCore project.

This leads to different representations of Guid being declared as Guid in EF and TEXT in EFCore. Also the name generation for foreign keys appears to be different, while EF generated names like Property_Id for relationships EFCore seems to create PropertyId instead.

Answer 1

First, I'd start by reverse engineering your existing SQLite database to an EF Core model. This will give you a good starting point.

Unfortunately, because SQLite only has four primitive types your model will only contain long, string, double, and byte[] properties (Upvote issue #8824 to improve this).

So, the next step will be to fix the types in your model to go back to the ones you were using before. When doing this, keep the default type mappings in mind.

As you noticed, some types like Guid may map to a different type by default. You can use EF Core value converts to compensate for these differences. For example, here's how to map all Guid values to BLOB.

// ...in your DbContext...

protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
{
    configurationBuilder.Properties<Guid>().HaveConversion<byte[]>();
}