Database in use error with Entity Framework 4 Code First

Dial down active connections

Sometimes EF grabs onto database connections like two lovers entwined in an eternal salsa dance. You may need to slide into SINGLE USER mode to extricate one partner:

ALTER DATABASE [YourDatabase] SET SINGLE_USER WITH ROLLBACK IMMEDIATE;
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Caution: Handle this partner-separating move like a delicate salsa dance, as it abruptly interrupts all other dance partners (a.k.a. all other connections).

Puppeteer your initializer: Decorator pattern, FTW!

You may even craft a custom initializer, say, a ForceDeleteInitializer, which adds some grace to an existing initializer by smoothly decorating its functionality:

public class ForceDeleteInitializer<TContext> : IDatabaseInitializer<TContext> where TContext : DbContext
{
    private IDatabaseInitializer<TContext> innerInitializer;

    public ForceDeleteInitializer(IDatabaseInitializer<TContext> inner)
    {
        innerInitializer = inner;
    }

    public void InitializeDatabase(TContext context)
    {
        // Time for some salsa solo, darling!
        context.Database.ExecuteSqlCommand(TransactionalBehavior.DoNotEnsureTransaction,
            "ALTER DATABASE [YourDatabase] SET SINGLE_USER WITH ROLLBACK IMMEDIATE");
        
        // Let the inner initializer shine!
        innerInitializer.InitializeDatabase(context);

        // Let's invite everyone back to the party!
    }
}
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When you're the puppeteer, remember to control all aspects for maximizing data sanctity safety nets!

Manage Connection Pools: Check before you dive in!

Connection pooling in EF can behave like a shark-infested ocean where your database is that unsuspecting surfer. Always remember to double-check before you dive in:

• Just saying "See ya later, alligator" after database operations and calling context.Database.Close() releases connections back into the pool.
• And if you're that daredevil wanting a cleared pool, SqlConnection.ClearAllPools() is your "clear the pool" cannonball.

When Tables Have the Last Laugh

Unaware of opened tables in management studio could lead to unintended comedy skits:

1. Close those chatterbox query windows.
2. Unplug and disconnect the management studio, if need be. Peace at last!

Unleashing the Power of Migrations

In the world of constantly evolving DB schema, migrations are your gallant knights:

• Have Enable-Migrations set sail in your Package Manager Console.
• Unleash Add-Migration [MigrationName] is your knight to script incremental schema changes.
• Crown Update-Database your king to enforce changes to the database.

An error sneaked in! Now what?

Whether it's active connections causing a riot or transaction scopes playing hide-n-seek, here's your plan of action:

• Don the detective cap and check the connection string.
• Seek solace in community arms for all things EF and ASP.NET MVC-offbeat.

Smooth DB Resets: Like a Boss!

Update your tactics! Use this little trick to auto-reset the database when your model changes take over:

Database.SetInitializer(new DropCreateDatabaseIfModelChanges<MyContext>());
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With it, EF manages schema changes implicitly and you don't need to drop the database manually. Quicker, cleaner, better!

Verifying DB status pre-operations: A Smart Move!

Right before you drop the database or mull over radical changes:

• Fire context.Database.Exists() to check if the database exists.
• Only then, carry on with operations. Because nobody has got time for unnecessary hurdles!

Custom Seeder Initializers: Ultimate Seed Sowers

Custom database initializers morph into your personal database seeding heroes:

public class SampleDataInitializer : DropCreateDatabaseIfModelChanges<MyContext>
{
    protected override void Seed(MyContext context)
    {
        // To seed or not to seed is no more a question!
        // Seed all the way...
        base.Seed(context);
    }
}
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A tailored seeder initializer paves way for a well-oiled and well-predicted database seeding mechanism.