How to determine database provider at the IEntityTypeConfiguration, because I support multiple databases

Question

Can anybody tell me how I can get the current database provider at line 9? So it can generated the migration correctly for the MySQL migrations. How do I do this the clean way.

1 internal class GroupConfiguration : IEntityTypeConfiguration<Group>
2 {
3   public void Configure(EntityTypeBuilder<Group> builder)
4   {
5      builder.ToTable(nameof(Group));
6      builder.HasKey("Id");
7      builder.Property(u => u.Id)
8         .ValueGeneratedOnAdd()
9         .HasDefaultValueSql((database.IsMySql()) ? "uuid()" : "newsequentialid()");
...

I'm using .NET Core 3.1, and my webapp supports multiple database providers. For now MySQL (Pomelo) and SQL Server. I need it to generate the migration the correct way. So I have a MySQL and SQL Server migrations.

But I don't want to update the MySQL generated migration manually.

Answer 1

The trick is to pass the DatabaseFacade to your configuration class:

internal class GroupConfiguration : IEntityTypeConfiguration<Group>
{
   private readonly DatabaseFacade _database;

   public GroupConfiguration(DatabaseFacade database)
   {
        _database = database;
   }

   public void Configure(EntityTypeBuilder<Group> builder)
   {
      builder.ToTable(nameof(Group));
      builder.HasKey("Id");
      builder.Property(u => u.Id)
         .ValueGeneratedOnAdd()
         .HasDefaultValueSql((_database.IsMySql()) ? "uuid()" : newsequentialid()");
...

And then pass the Database property in OnModelCreating:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    // ...
    modelBuilder.ApplyConfiguration(new GroupConfiguration(Database));
    // ...
}

Keep in mind that the configuration class can no longer be created by modelBuilder.ApplyConfigurationsFromAssembly(), so you have to add the configuration with modelBuilder.ApplyConfiguration().