CSharpMongoMigrations

What is it?

CSharpMongoMigrations is an alternative .NET library for mongo migrations. Despite of the official package library allows both the Up and the Down data migrations. It's a big advantage for huge MongoDb projects. Moreover solution does not have any dependencies from the outdated MongoDb driver. So you don't need to reference two different versions of the driver.

Installation

Nuget

Install-Package CSharpMongoMigrations

From Source

> git clone https://github.com/VladimirRybalko/CSharpMongoMigrations.git

Documentation API

There are two types of migrations in solution.

1. Migration

   [Migration(0, "Add John Doe")]
    public class AddPersonMigration : Migration
    {
        public override void Up()
        {
            var collection = GetCollection("Persons");
            var document = new BsonDocument();

            document.AddUniqueIdentifier(new Guid("06BFFCF5-DAE9-422A-85AB-F58DE41E86DA"));
            document.AddProperty("Name", "John Doe");
            
            collection.InsertOne(document);
        }

        public override void Down()
        {
            var collection = GetCollection("Persons");
            var idFilter = Builders<BsonDocument>.Filter.Eq("_id", new Guid("06BFFCF5-DAE9-422A-85AB-F58DE41E86DA"));
            collection.DeleteOne(idFilter);
        }
    }

Here we define the Up migration to added John Doe to Person collection. The Down method roll back the migration and restore database to the original state.

Take attention to Migration attribute. It's required to running migration by launcher. You should define the migration number ('0' in example) and description (Add John Doe'). Note that each migration must have the unique number and arbitrary description.

2. Document migration

Such migrations allow to apply changes to each document in the specified collection.

   [Migration(1, "Change persons")]
    public class AddPropertyPersonMigration : DocumentMigration
    {
        protected override string CollectionName { get { return "Persons"; } }
               
        protected override void UpgradeDocument(BsonDocument document)
        {
            document.AddProperty("IsActive", true);            
        }

        protected override void DowngradeDocument(BsonDocument document)
        {
            document.RemoveProperty("IsActive");
        }
    }

You can find more detailed examples in CSharpMongoMigrations.Demo project.

How to launch migrations?

It's a really simple. You should create an instance of MigrationRunner class.

   var runner = new MigrationRunner("<mongoDb_connection_string>", "<database_name>", "<location_to_assembly_with_migrations>");

Then you can call Up or Down method to apply or downgrade migrations.

   // Apply all migrations before specified version.
   // Use -1 to apply all existing migrations. ('-1' is a default parameter value)
   runner.Up("<version>"); 
   
   // Roll back all migrations after specified version.
   // Use -1 to downgrade all existing migrations. ('-1' is a default parameter value)
   runner.Down("<version>");