MongoDB.EntityFrameworkCore

MongoDB Entity Framework Core Provider

The MongoDB EF Core Provider requires Entity Framework Core 8 or 9 on .NET 8 or later and a MongoDB database server 5.0 or later, preferably in a transaction-enabled configuration.

Getting Started

Setup a DbContext with your desired entities and configuration

internal class PlanetDbContext : DbContext
{
    public DbSet<Planet> Planets { get; init; }

    public static PlanetDbContext Create(IMongoDatabase database) =>
        new(new DbContextOptionsBuilder<PlanetDbContext>()
            .UseMongoDB(database.Client, database.DatabaseNamespace.DatabaseName)
            .Options);

    public PlanetDbContext(DbContextOptions options)
        : base(options)
    {
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Entity<Planet>().ToCollection("planets");
    }
}

To get going with the DbContext:

var mongoConnectionString = Environment.GetEnvironmentVariable("MONGODB_URI");
var mongoClient = new MongoClient(mongoConnectionString);
var db = PlanetDbContext.Create(mongoClient.GetDatabase("planets"));
db.Database.EnsureCreated();

Supported Features

Entity Framework Core and MongoDB have a wide variety of features. This provider supports a subset of the functionality available in both, specifically:

• Querying with Where, Find, First, Single, OrderBy, ThenBy, Skip, Take etc.
• Top-level aggregate Any, Count, LongCount, Sum, Min, Max, Average, All
• Mapping properties to BSON elements using [Column] or [BsonElement] attributes or HasElementName("name") method
• Mapping entities to collections via [Table("name")], ToCollection("name") or by convention from the DbSet property name
• Single or composite keys of standard types including string, Guid and ObjectId etc.
• Properties with typical CLR types (int, string, Guid, decimal, DateOnly etc.) & MongoDB types (ObjectId, Decimal128)
• Properties that are arrays, lists, dictionaries (string keys) of simple CLR types including binary byte[]
• Owned entities (aka value types, sub-documents, embedded documents) both directly and in collection properties
• BsonIgnore, BsonId, BsonDateTimeOptions, BsonElement, BsonRepresentation and BsonRequired support
• Storage type configuration through EF ValueConverters or BSON representation attributes and fluent APIs
• Query and update logging of MQL (sensitive logging must be enabled)
• EnsureCreated & EnsureDeleted to ensure collections and the database created at app start-up
• Optimistic concurrency support through IsConcurrencyToken/ConcurrencyCheckAttribute & IsRowVersion/TimestampAttribute
• AutoTransactional SaveChanges & SaveChangesAsync - all changes committed or rolled-back together
• CamelCaseElementNameConvention for helping map Pascal-cased C# properties to camel-cased BSON elements
• Type discriminators including OfType<T> and Where(e => e is T)
• Support for EF shadow properties and EF.Proxy for navigation traversal
• Client Side Field Level Encryption and Queryable Encryption compatibility

Limitations

A number of Entity Framework Core features are not currently supported but planned for future release. If you require use of these facilities in the mean-time consider using the existing MongoDB C# Driver's LINQ provider which may support them.

Planned for future releases

• Select projections with client-side operations
• GroupBy operations
• Includes/joins
• Geospatial
• Atlas search
• ExecuteUpdate & ExecuteDelete bulk operations (EF 9 only)

Not supported, out-of-scope features

• Keyless entity types
• Schema migrations
• Database-first & model-first
• Alternate keys
• Document (table) splitting
• Temporal tables
• Timeseries
• GridFS

Breaking changes

This project's version-numbers are aligned with Entity Framework Core and as-such we can not use the semver convention of constraining breaking changes solely to major version numbers. Please keep an eye on our Breaking Changes document before upgrading to a new version of this provider.

Documentation

• MongoDB
• EF Provider Guide
• EF Provider API Docs

Questions/Bug Reports

• Forums
• Jira

If you’ve identified a security vulnerability in a driver or any other MongoDB project, please report it according to the instructions here.

Contributing

Please see our guidelines for contributing to the driver.

Thank you to everyone who has contributed to this project.