New Post: Multiple contexts per db and automatic migration

Hi Andrew,

thanks for your hints. I could get rid of the derived migration configs by setting the correct assembly and namespace. This way the initial migrations for each context are found and applied correctly. That's a first little success!

Without this first initial code-based migration there is always this exception:
Automatic migrations that affect the location of the migrations history system table (such as default schema changes) are not supported. Please use code-based migrations for operations that affect the location of the migrations history system table.

However, this initial DbMigration feels redundant, because the migration process looks like this:
1) No/empty db -> initial code-based and possibly outdated migration is applied
2) The current model has changed since the initial migration -> another automatic migration is created and applied

Is this first migration really neccessary (technically), when you could just apply the current model state directly?
(I also thought about a creating a faked initial code-based migration manually, that has an empty model (similar to http://stackoverflow.com/a/15027630), to avoid having an outdated code-based migration with a few hundred lines of outdated code...)

Thanks for your help
mat

Here is my MigrationInitializer:

    public class MigrationInitializer<TContext>
        : IDatabaseInitializer<TContext>
        where TContext : DbContext, new()
    {
        private readonly string _connectionString;

        public MigrationInitializer(string connectionString)
        {
            _connectionString = connectionString;
        }

        public void InitializeDatabase(TContext context)
        {
            try
            {
                // database already compatible?
                var isCompatible = true;
                try { isCompatible = context.Database.CompatibleWithModel(true); }
                catch (Exception) { isCompatible = false; }
                if (isCompatible)
                    return;

                // apply current connection
                var contextType = typeof(TContext);
                var config = new DbMigrationsConfiguration<TContext> {
                    AutomaticMigrationsEnabled = true,
                    AutomaticMigrationDataLossAllowed = true,
                    ContextKey = contextType.Name,
                    MigrationsAssembly = contextType.Assembly,
                    MigrationsNamespace = contextType.Namespace + ".Migrations",
                    TargetDatabase = new DbConnectionInfo(
                        context.Database.Connection.ConnectionString,
                        "System.Data.SqlClient") };

                // migrate to latest version
                var migrator = new DbMigrator(config);
                migrator.Update();
            }
            catch (Exception) { ... }
        }
    }