LiteDB.Migration

LiteDB.Migration is a library for migrating schema changes in LiteDB databases.

Features

• Flexible Migration Paths: Migrate data across multiple versions with ease.
• Simple API: Define your migrations using a simple API.
• Implicit and Explicit Migrations: Migrate all at once or in a Lazy way.

Getting Started

Installation

LiteDB.Migration is available as a NuGet package. You can install it via the NuGet Package Manager or the CLI:

dotnet add package LiteDB.Migration

Basic Usage

Get started by following the steps below. For a full example, see the Tests

1. Define Your Models: Start by defining your document models. For each version change that requires a migration, prepare a new version of the model.

// Initial model
public class EntryModel
{
    public int Id { get; set; }
    public string OldProperty { get; set; }
}

// The latest version of the model, which is actively used in your app
public class CurrentModel
{
    public int Id { get; set; }
    public string NewestProperty { get; set; }
}

2. Seed Data: Seed your database with the original model.

 // seed db
using (var db = new LiteDatabase("YourDatabase.db"))
{
    var col = db.GetCollection<EntryModel>("ModelX");
    col.Insert(new EntryModel { Id = 1, OldProperty = "OldValue" });
}

3. Define and apply Migrations: Define your migrations using the MigrationContainer class and apply them using the MigrationContainer class.
   Whenever you want to change the model, you can define a new migration using the WithMigration method.

 // apply migration
using (var db = new LiteDatabase("YourDatabase.db"))
{
    var container = new MigrationContainer(migConfig =>
    {
        migConfig.Collection<CurrentModel>("ModelX", config => config
            .StartWithModel<EntryModel>()
            .WithMigration(x => new
            {
                x.Id,
                NewProperty = "New-" + x.OldProperty
            })
            .WithMigration(x => new
            {
                x.Id,
                NewestProperty = "New-" + x.NewProperty
            })
        );
    });

    container.Apply(db);
}

1. Query Data: Query your database using the new model.

// verify migration
using (var db = new LiteDatabase("YourDatabase.db"))
{
    var col = db.GetCollection<CurrentModel>("ModelX");
    var model = col.FindById(1);

    Console.WriteLine($"Id: {model.Id}, NewestProperty: {model.NewestProperty}");
    if (model.Id != 1 || model.NewestProperty != "New-New-OldValue")
    {
        throw new Exception("Migration failed");
    }
    else
    {
        Console.WriteLine("Migration succeeded");
    }
}

Advanced Usage

For larger (enterprise) applications, you may want to use a more structured approach to migrations. In this case, you can use the please see the Full Example (Wiki page coming soon).

Contributing

Contributions are welcome! Feel free to submit

• pull requests
• report issues
• feature requests

If you are motivated to create something like dotnet-ef cli tool, feel free to do so and submit a pull request :)

License

LiteDB.Migration is released under the MIT License. See the LICENSE file for more details.