Async query in Entity Framework

Question

I'm in C# and using Entity Framework with a database-first approach, and I would like to do a query similar to this query but in an asynchronous way:

[Route("api/Tests/get/by/flight/{id}")]
[ResponseType(typeof(Test))]
public IHttpActionResult getByFlightTodayId(int id)
{
    var testList = db.Tests.SqlQuery("Select * from Tests where Tests.AircraftId=@id", new SqlParameter("@id", id)).ToList<Test>();
    return Ok(testList);
}

I have an example but it returns only one result - not an array.

[Route("api/Tests/get/by/flight/{id}")]
[ResponseType(typeof(Test))]
public async Task<IHttpActionResult> getByFlightId(int id)
{
    Test test = await db.Tests.FirstAsync(r => r.AircraftId == id);

    if (test == null)
    {
        return NotFound();
    }

    return Ok(test);
}

Also, I want to do an inner join query but I don't know how to do this.

Can someone help me?

Thanks

Do you have foreign key references between tables means, you can use db.Tests.Include(x=>x.TableName) — sri harsha
– sri harsha, Commented Dec 23, 2019 at 12:52
It's not very clear what you're trying to achieve, can you add an example of what result are you expecting? — Vargan
– Vargan, Commented Dec 23, 2019 at 13:03
Tests.aircraftId is a foreign key and I want all the tests an aircraft passed — loryn
– loryn, Commented Dec 23, 2019 at 13:07

sri harsha · Accepted Answer · 2019-12-23 14:27:36Z

3

Use like below:

var test = await db.Tests.Where(r => r.AircraftId == id).ToListAsync();

For Inner join, there will be foreign key relationship between 2 tables. Then you can use below query:

var test = await db.Aircraft.Include(x=>x.Tests).ToListAsync();

You can apply .Where condition, if you want to filter records in that.

edited Dec 23, 2019 at 14:27

answered Dec 23, 2019 at 12:50

sri harsha

6806 silver badges16 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

loryn Over a year ago

I do this but an error occured : "Cannot implicitly convert type : 'system.Collections.Generic.List<toulouseTech2;Models.Test>' to 'toulouseTech2.Models.Test'

sri harsha Over a year ago

Try now, change Test to var or List<Test>

loryn Over a year ago

it's working !!! Thanks a lot. Can you tell me how can I do this for an inner join query like : Select * From Aircraft Inner Join Test On aircraft.Id = test.AircraftId

Collectives™ on Stack Overflow

Async query in Entity Framework

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related