README.md

📖 About mongomigrations.core

Build server	Platforms	Build status
Github Actions	ubuntu-latest	Branch: develop
Github Actions	ubuntu-latest	Branch: master

🚀 Getting Started Guide

Typed migrations for MongoDB.

Migration runner

The migration runner executes migrations. The default collection name, is DatabaseVersion. Upon application startup, e.g. in ASP.NET Core you should invoke UpdateToLatest before any controller actions or hangfire jobs are executed. This method is safe to invoke in a distributed environment, e.g. a IIS web farm.

var migrationRunner = new MigrationRunner("connectionString");
migrationRunner.MigrationLocator.LookForMigrationsInAssembly(typeof(Migration1).Assembly);
retryMigration:
try
{
    migrationRunner.UpdateToLatest(Environment.MachineName);
}
catch (ConcurrentMigrationException)
{
    Thread.Sleep(5000);

    goto retryMigration;
}

Migrate a single collection

class Migration1 : Migration
{
    public Migration1() : base(1)
    {
        Description = "Drop a collection";
    }

    public override void Update()
    {
        Database.DropCollection("Collection");
    }
}

Migrate all documents in a collection

class Migration2 : CollectionMigration
{

    public Migration2() : base(2, "Collection")
    {
        Description = "Ensure all documents has a Reference property";
        // Execute batch writes when 1000 documents has been migrated.
        BatchSize = 1000;
    }

    public override IEnumerable<IWriteModel> MigrateDocument(MigrationDocument document)
    {
        if (!document.BsonDocument.TryGetElement("Reference", out _))
        {
            return document.Skip();
        }
      
        return document.Update(x => x.Set("Reference", BsonNull.Value));
    }

    public override void OnBeforeMigration()
    {
      // Is invoked before any migrations are migrated.
    }

    public override void OnAfterSuccessfulMigration()
    {
        // Is executed after all documents has been migrated.
    }
}