CODEWITHSUNDEEP
c#asp.net-mvclinqrazor
user2224493
user2224493

Reputation: 269

Linq statement to return number of rows

I am passing assesment model to the Results Action using redirect to action. In the Results action controller I would like to to execute a linq statement to retrieve the number of rows using the repository and whatever values are posted.for example

number of rows = Select * 
                 from table or model
                 where SmokesInHouse = SmokesInHouse And
                       SmokesInCar = SmokesInCar And
                       SmokesAtWork = SmokesAtWork'

public class SampleController : Controller
{
    private IEnvRepository repository;

    public SampleController(IEnvRepository assesmentRepository)
    {
        repository = assesmentRepository;
    }

    [HttpPost]
    public ActionResult SmokingEnvironments(Assessment a)
    {
        if (ModelState.IsValid)

            return RedirectToAction("Results", new { SmokesInHouse =SmokesInHouse,        SmokesInCar  = a.SmokesInCar, SmokesAtWork=a.SmokesAtWork });
        }
        return View(a);
    }

    [HttpGet]
    public ActionResult Results()
    {
        return View();
    }
}

Upvotes: 0

Views: 4118

Answers (3)

Paulo Morgado
Paulo Morgado

Reputation: 14846

There's an overload of the Count method that takes a predicate. With it the query can be simplified to something like:

int totalSmokers = xs.Count(x =>
    x.SmokesInHouse == a.SmokesInHouse &&
    x.SmokesInCar == a.SmokesInCar &&
    x.SmokesAtWork == a.SmokesAtWork);

I'm assuming this is an IQueryable that will be executed on the server and it might not make difference. But if it was an IEnumerable it could make a difference for large sequences.

Upvotes: 0

M i r h a
M i r h a

Reputation: 36

Try the following to get the total number of smokers in your model:

int totalSmokers = model.Where(x => x.SmokesInHouse && x.SmokesInCar && x.SmokesAtWork).Count();

You would use the same where clause if querying from a database table.

Upvotes: 1

James
James

Reputation: 82096

You need to update the Results action to accept the Assessment model i.e.

[HttpGet]
public ActionResult Results(AssessmentModel assessment)
{
    int rows = myTable.Where(x => x.SmokesInHouse == assessment.SmokesInHouse &&
                                  x.SmokesInCar == assessment.SmokesInCar &&
                                  x.SmokesAtWork == assessment.SmokesInWork).Count();
    return View(rows);
}

Upvotes: 3

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