ABP can automatically create [repositories](Repositories.md) for the entities in your DbContext. Just use `AddDefaultRepositories()` option on registration:
ABP can automatically create default [generic repositories](Repositories.md) for the entities in your DbContext. Just use `AddDefaultRepositories()` option on the registration:
This will create a repository for each aggreate root entity (classes derived from AggregateRoot) by default. If you want to create repositories for other entities too, then set `includeAllEntities` to `true`:
This will create a repository for each [aggregate root entity](Entities.md) (classes derived from `AggregateRoot`) by default. If you want to create repositories for other entities too, then set `includeAllEntities` to `true`:
public BookManager(IRepository<Book,Guid> bookRepository) //inject default repository
{
_bookRepository = bookRepository;
}
public async Task<Book> CreateBook(string name, BookType type)
{
Check.NotNullOrWhiteSpace(name, nameof(name));
var book = new Book
{
Id = GuidGenerator.Create(),
Name = name,
Type = type
};
await _bookRepository.InsertAsync(book); //Use a standard repository method
return book;
}
}
```
This sample uses `InsertAsync` method to insert a new entity to the database.
#### Add Custom Repositories
Default generic repositories are powerful enough in most cases (since they implement `IQueryable`). However, you may need to create a custom repository to add your own repository methods.
Assume that you want to delete all books by type. It's suggested to define an interface for your custom repository:
```csharp
public interface IBookRepository : IRepository<Book,Guid>
You generally want to derive from the `IRepository` to inherit standard repository methods. However, you don't have to. Repository interfaces are defined in the domain layer of a layered application. They are implemented in the data/infrastructure layer (`MongoDB` project in a [startup template](https://abp.io/Templates)).
Example implementation of the `IBookRepository` interface:
Now, it's possible to [inject](Dependency-Injection.md) the `IBookRepository` and use the `DeleteBooksByType` method when needed.
##### Override Default Generic Repository
Even if you create a custom repository, you can still inject the default generic repository (`IRepository<Book,Guid>` for this example). Default repository implementation will not use the class you have created.
If you want to replace default repository implementation with your custom repository, do it inside `AddMongoDbContext` options:
This is especially important when you want to **override a base repository method** to customize it. For instance, you may want to override `DeleteAsync` method to delete an entity in a more efficient way:
```csharp
public override async Task DeleteAsync(
Guid id,
bool autoSave = false,
CancellationToken cancellationToken = default)
{
//TODO: Custom implementation of the delete method
}
```
#### Access to the MongoDB API
In most cases, you want to hide MongoDB APIs behind a repository (this is the main purpose of the repository). However, if you want to access the MongoDB API over the repository, you can use `GetDatabase()` or `GetCollection()` extension methods. Example:
> Important: You must reference to the `Volo.Abp.MongoDB` package from the project you want to access to the MongoDB API. This breaks encapsulation, but this is what you want in that case.
#### Advanced Topics
##### Set Default Repository Classes
Default generic repositories are implemented by `MongoDbRepository` class by default. You can create your own implementation and use it for default repository implementation.
public MyRepositoryBase(IMongoDbContextProvider<BookStoreMongoDbContext> dbContextProvider)
: base(dbContextProvider)
{
}
}
```
First one is for [entities with composite keys](Entities.md), second one is for entities with single primary key.
It's suggested to inherit from the `MongoDbRepository` class and override methods if needed. Otherwise, you will have to implement all standard repository methods manually.
Now, you can use `SetDefaultRepositoryClasses` option:
##### Set Base MongoDbContext Class or Interface for Default Repositories
If your MongoDbContext inherits from another MongoDbContext or implements an interface, you can use that base class or interface as the MongoDbContext for default repositories. Example:
```csharp
public interface IBookStoreMongoDbContext : IAbpMongoDbContext
{
Collection<Book> Books { get; }
}
```
`IBookStoreMongoDbContext` is implemented by the `BookStoreMongoDbContext` class. Then you can use generic overload of the `AddDefaultRepositories`:
In this example, `OtherMongoDbContext` implements `IBookStoreMongoDbContext`. This feature allows you to have multiple MongoDbContext (one per module) on development, but single MongoDbContext (implements all interfaces of all MongoDbContexts) on runtime.
Halil ibrahim Kalkan
7 years ago