EntityFramework code-first custom connection string and migrations

Red XIII picture Red XIII · Mar 19, 2013 · Viewed 36.5k times · Source

When I create a context with a default connection string (as read from the app.config) the database is created and the migrations work - basically everything is in order. Whereas when the connection string is created programatically (using SqlConnectionStringBuilder):

  • database isn't created when the database is not present (scenario A);
  • CreateDbIfNotExists() creates the newest version of database model but the migration mechanisms are not invoked (scenario B).

In A an exception is thrown when I wish to access the database, as - obviously - it isn't there. In B database is created properly migration mechanisms are not called, as is the case in standard connection string.

app.config: "Data Source=localhost\\SQLEXPRESS;Initial Catalog=Db13;User ID=xxx;Password=xxx"

builder:

sqlBuilder.DataSource = x.DbHost;
sqlBuilder.InitialCatalog = x.DbName;
sqlBuilder.UserID = x.DbUser;
sqlBuilder.Password = x.DbPassword;

initializer:

Database.SetInitializer(
    new MigrateDatabaseToLatestVersion<
        MyContext,
        Migrations.Configuration
    >()
);

Specs: Entity Framework: 5.0, DB: SQL Server Express 2008

Answer

rraszewski picture rraszewski · Apr 10, 2013

If your migration does not work correctly try to set Database.Initialize(true) in DbContext ctor.

public CustomContext(DbConnection connection)
: base(connection, true)    
{    
        Database.Initialize(true);    
}    

I have similar problem with migrations. And in my solution I have to always set database initializer in ctor, like below

public CustomContext(DbConnection connection)
: base(connection, true)    
{    
        Database.SetInitializer(new CustomInitializer());
        Database.Initialize(true);    
}    

In custom initializer you have to implement InitalizeDatabase(CustomContex context) method, eg.

class CustomInitializer : IDatabaseInitializer<CustomContext>
{
    public void InitializeDatabase(CustomContext context)
    {
        if (!context.Database.Exists || !context.Database.CompatibleWithModel(false))
        {
            var configuration = new Configuration();
            var migrator = new DbMigrator(configuration);
            migrator.Configuration.TargetDatabase = new DbConnectionInfo(context.Database.Connection.ConnectionString, "System.Data.SqlClient");
            var migrations = migrator.GetPendingMigrations();
            if (migrations.Any())
            {
                var scriptor = new MigratorScriptingDecorator(migrator);
                string script = scriptor.ScriptUpdate(null, migrations.Last());
                if (!String.IsNullOrEmpty(script))
                {
                    context.Database.ExecuteSqlCommand(script);
                }
            }
        }
    }
}

UPDATED