abp-mongodb

name	abp-mongodb
license	UNLICENSED
description	Use when working in MongoDB projects or implementing MongoDB repositories in ABP. Covers AbpMongoDbContext, IMongoCollection, MongoDbRepository, no migrations, embedded documents vs references, and manual UpdateAsync required.

ABP MongoDB

Docs: https://abp.io/docs/latest/framework/data/mongodb

MongoDbContext Configuration

[ConnectionStringName("Default")]
public class MyProjectMongoDbContext : AbpMongoDbContext
{
    public IMongoCollection<Book> Books => Collection<Book>();
    public IMongoCollection<Author> Authors => Collection<Author>();

    protected override void CreateModel(IMongoModelBuilder modelBuilder)
    {
        base.CreateModel(modelBuilder);

        modelBuilder.ConfigureMyProject();
    }
}

Entity Configuration

public static class MyProjectMongoDbContextExtensions
{
    public static void ConfigureMyProject(this IMongoModelBuilder builder)
    {
        Check.NotNull(builder, nameof(builder));

        builder.Entity<Book>(b =>
        {
            b.CollectionName = MyProjectConsts.DbTablePrefix + "Books";
        });

        builder.Entity<Author>(b =>
        {
            b.CollectionName = MyProjectConsts.DbTablePrefix + "Authors";
        });
    }
}

Repository Implementation

public class BookRepository : MongoDbRepository<MyProjectMongoDbContext, Book, Guid>, IBookRepository
{
    public BookRepository(IMongoDbContextProvider<MyProjectMongoDbContext> dbContextProvider)
        : base(dbContextProvider)
    {
    }

    public async Task<Book> FindByNameAsync(
        string name,
        bool includeDetails = true,
        CancellationToken cancellationToken = default)
    {
        return await (await GetQueryableAsync())
            .FirstOrDefaultAsync(
                b => b.Name == name,
                GetCancellationToken(cancellationToken));
    }

    public async Task<List<Book>> GetListByAuthorAsync(
        Guid authorId,
        bool includeDetails = false,
        CancellationToken cancellationToken = default)
    {
        return await (await GetQueryableAsync())
            .Where(b => b.AuthorId == authorId)
            .ToListAsync(GetCancellationToken(cancellationToken));
    }
}

Module Configuration

[DependsOn(typeof(AbpMongoDbModule))]
public class MyProjectMongoDbModule : AbpModule
{
    public override void ConfigureServices(ServiceConfigurationContext context)
    {
        context.Services.AddMongoDbContext<MyProjectMongoDbContext>(options =>
        {
            // Add default repositories for aggregate roots only (DDD best practice)
            options.AddDefaultRepositories();
            // ⚠️ Avoid includeAllEntities: true - breaks DDD data consistency
        });
    }
}

Connection String

In appsettings.json:

{
  "ConnectionStrings": {
    "Default": "mongodb://localhost:27017/MyProjectDb"
  }
}

Key Differences from EF Core

No Migrations

MongoDB is schema-less; no migrations needed. Changes to entity structure are handled automatically.

includeDetails Parameter

Often ignored in MongoDB because documents typically embed related data:

public async Task<List<Book>> GetListAsync(
    bool includeDetails = false, // Usually ignored
    CancellationToken cancellationToken = default)
{
    // MongoDB documents already include nested data
    return await (await GetQueryableAsync())
        .ToListAsync(GetCancellationToken(cancellationToken));
}

Embedded Documents vs References

// Embedded (stored in same document)
public class Order : AggregateRoot<Guid>
{
    public List<OrderLine> Lines { get; set; } // Embedded
}

// Reference (separate collection, store ID only)
public class Order : AggregateRoot<Guid>
{
    public Guid CustomerId { get; set; } // Reference by ID
}

No Change Tracking

MongoDB doesn't track entity changes automatically:

public async Task UpdateBookAsync(Guid id, string newName)
{
    var book = await _bookRepository.GetAsync(id);
    book.SetName(newName);

    // Must explicitly update
    await _bookRepository.UpdateAsync(book);
}

Direct Collection Access

public async Task CustomOperationAsync()
{
    var collection = await GetCollectionAsync();

    // Use MongoDB driver directly
    var filter = Builders<Book>.Filter.Eq(b => b.AuthorId, authorId);
    var update = Builders<Book>.Update.Set(b => b.IsPublished, true);

    await collection.UpdateManyAsync(filter, update);
}

Indexing

Configure indexes in repository or via MongoDB driver:

public class BookRepository : MongoDbRepository<MyProjectMongoDbContext, Book, Guid>, IBookRepository
{
    public override async Task<IQueryable<Book>> GetQueryableAsync()
    {
        var collection = await GetCollectionAsync();

        // Ensure index exists
        var indexKeys = Builders<Book>.IndexKeys.Ascending(b => b.Name);
        await collection.Indexes.CreateOneAsync(new CreateIndexModel<Book>(indexKeys));

        return await base.GetQueryableAsync();
    }
}

Best Practices

• Design documents for query patterns (denormalize when needed)
• Use references for frequently changing data
• Use embedding for data that's always accessed together
• Add indexes for frequently queried fields
• Use GetCancellationToken(cancellationToken) for proper cancellation
• Remember: ABP data filters (soft-delete, multi-tenancy) work with MongoDB too