> Note that in order to use the async LINQ extension methods (like `ToListAsync` here), you may need to depend on the database provider (like EF Core) since these methods are defined in the database provider package, they are not standard LINQ methods.
> Note that in order to use the async LINQ extension methods (like `ToListAsync` here), you may need to depend on the database provider (like EF Core) since these methods are defined in the database provider package, they are not standard LINQ methods. See the [repository document](Repositories.md) for alternative approaches for async query execution.
@ -222,7 +222,8 @@ public class PersonRepository : EfCoreRepository<MyDbContext, Person, Guid>, IPe
public async Task<Person> FindByNameAsync(string name)
{
return await DbContext.Set<Person>()
var dbSet = await GetDbSetAsync();
return await dbSet.Set<Person>()
.Where(p => p.Name == name)
.FirstOrDefaultAsync();
}
@ -235,12 +236,13 @@ You can directly access the data access provider (`DbContext` in this case) to p
## IQueryable & Async Operations
`IRepository`inherits from`IQueryable`, that means you can **directly use LINQ extension methods** on it, as shown in the example of the "*Generic Repositories*" section above.
`IRepository`provides `GetQueryableAsync()` to obtain an`IQueryable`, that means you can **directly use LINQ extension methods** on it, as shown in the example of the "*Querying / LINQ over the Repositories*" section above.
**Example: Using the `Where(...)` and the `ToList()` extension methods**
````csharp
var people = _personRepository
var queryable = await _personRepository.GetQueryableAsync();
var people = queryable
.Where(p => p.Name.Contains(nameFilter))
.ToList();
````
@ -269,7 +271,8 @@ When you add the NuGet package to your project, you can take full power of the E
**Example: Directly using the `ToListAsync()` after adding the EF Core package**
````csharp
var people = _personRepository
var queryable = await _personRepository.GetQueryableAsync();
var people = queryable
.Where(p => p.Name.Contains(nameFilter))
.ToListAsync();
````
@ -285,7 +288,8 @@ If you are using [MongoDB](MongoDB.md), you need to add the [Volo.Abp.MongoDB](h
**Example: Cast `IQueryable<T>` to `IMongoQueryable<T>` and use `ToListAsync()`**
````csharp
var people = ((IMongoQueryable<Person>)_personRepository
var queryable = await _personRepository.GetQueryableAsync();
var people = ((IMongoQueryable<Person>) queryable
.Where(p => p.Name.Contains(nameFilter)))
.ToListAsync();
````
@ -312,10 +316,11 @@ The standard LINQ extension methods are supported: *AllAsync, AnyAsync, AverageA
This approach still **has a limitation**. You need to call the extension method directly on the repository object. For example, the below usage is **not supported**:
```csharp
var count = await _bookRepository.Where(x => x.Name.Contains("A")).CountAsync();
var queryable = await _bookRepository.GetQueryableAsync();
var count = await queryable.Where(x => x.Name.Contains("A")).CountAsync();
```
This is because the object returned from the `Where` method is not a repository object, it is a standard `IQueryable` interface. See the other options for such cases.
This is because the `CountAsync()` method in this example is called on a `IQueryable` interface, not on the repository object. See the other options for such cases.
This method is suggested **wherever possible**.
@ -352,8 +357,11 @@ namespace AbpDemo
public async Task<ListResultDto<ProductDto>> GetListAsync(string name)
{
//Obtain the IQueryable<T>
var queryable = await _productRepository.GetQueryableAsync();
Halil İbrahim Kalkan
5 years ago