CasperTDK/migr8

Migr8

Execute the migrations - either in a dedicated command line app, or - my favorite - whenever your app starts up, just before it connects to the database:

Migrate.Database("db");

where db is a key in the connectionStrings section of your app.config/web.config, and then, elsewhere in the calling assembly, you define these bad boys:

[Migration(1, "Create table for the Timeout Manager to use")]
class CreateRebusTimeoutsTable : ISqlMigration
{
    public string Sql
    {
        get { return @"

            CREATE TABLE [dbo].[timeouts](
                [time_to_return] [datetime] NOT NULL,
                [correlation_id] [nvarchar](200) NOT NULL,
                [saga_id] [uniqueidentifier] NOT NULL,
                [reply_to] [nvarchar](200) NOT NULL,
                [custom_data] [nvarchar](max) NULL,
             CONSTRAINT [PK_timeouts] PRIMARY KEY CLUSTERED 
            (
                [time_to_return] ASC,
                [correlation_id] ASC,
                [reply_to] ASC
            )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, 
                IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, 
                ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
            ) ON [PRIMARY]

			"; 
		}
    }
}

[Migration(2, "Create a table for Rebus publishers to use")]
class CreateRebusSubscriptionsTable : ISqlMigration
{
    public string Sql
    {
        get { return @"

            CREATE TABLE [dbo].[subscriptions](
                [message_type] [nvarchar](200) NOT NULL,
                [endpoint] [nvarchar](200) NOT NULL,
             CONSTRAINT [PK_subscriptions] PRIMARY KEY CLUSTERED 
            (
                [message_type] ASC,
                [endpoint] ASC
            )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, 
                IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, 
                ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
            ) ON [PRIMARY]

			"; 
		}
    }
}

If you want to be more explicit, you can also go

// this is how all the migrations are picked up
var provideMigrations = new AssemblyScanner(typeof(AnEntity).Assembly, typeof(AnotherEntity).Assembly);

// this one finds out which ones to execute, validates the sequence, and executes
new DatabaseMigrator(myConnectionString, provideMigrations).MigrateDatabase();

Brief info

The version number of the database is stored in an extended property called migr8_database_version.

Each migration is executed in a transaction, execution stops if one fails.

Events are raised before/after and in the event of an error.

If you go in your SQL script, the preceding block will be executed - just like you're used to, just without the compilation errors if you rename stuff.

What to do?

First: Use migr8 if you need to treat your database with some evolutionary friction-free schema and data migrations.

Second: lean back, chill.....