How to make use of EF CodeFirst Migrations without hardcoding nameOrConnectionString

Question

How can you make EF migrations work without hardcoding a nameorconnectionstring in the base of the required parameterless constructor?

EF migrations is forcing you to add a default constructor to the custom dbcontext. In the base of the dbcontext you have to provide a nameorconnectionstring.

public class CustomDbContext : DbContextBase
    {
        public CustomDbContext ()
            : base("theconnectionstringwedontwanttoset") //hardcoded connection string
        {
        }

The fact that we need to hardcode the constructor is something we cant work with since in our client applications we work without a config file and we dynamically build up the connection since we are connecting to many different databases (server, local sql compact).

After exploring the DbMigrationsConfiguration class I found a DbConnectionsInfo property named TargetDatabase which can be set in the constructor. But even this solution did not work. This is what I did:

public sealed class Configuration : DbMigrationsConfiguration<CustomDbContext>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = true;
            //Setting the TargetDatabase in the hope it will use it in the migration  
            TargetDatabase = new DbConnectionInfo("Server=xxx;Database=xxx;Trusted_Connection=True", "System.Data.SqlClient");
        }


public class MigrationInitializer : MigrateDatabaseToLatestVersion<CustomDbContext, Configuration>
    {
    }

I can see that eventually the Activator.CreateInstance is used within DbMigrator and I expected from this class to use the TargetDatabase.Create...or something.

Any help or feedback is welcome.

Thanks in advance,

Wilko

Answer 1

it is possible yes See answers here I also included a test program in this question.