CODEWITHSUNDEEP
asp.net-mvclinq
hncl
hncl

Reputation: 2295

MVC C# Select Where

I am trying to add filter by ID for the following: 

public ActionResult Index()
{
    var model = from o in new MainDBContext().OffLinePayments
                select new EditOffLinePayment 
                {
                    ID = o.ID,
                    Amount = o.Amount 
                };
    return View(model);
}

What I would like to do is the following:

public ActionResult Index(long? id)
{
    if (id != null)
    {
        var model = from o in new MainDBContext().OffLinePayments
                    **Where Assigned_ID == id**
                    select new EditOffLinePayment 
                    {
                        ID = o.ID,
                        Amount = o.Amount 
                    };
        return View(model);
    }
    else 
    {       
        var model = from o in new MainDBContext().OffLinePayments
                    select new EditOffLinePayment 
                    {
                        ID = o.ID,
                        Amount = o.Amount 
                    };
        return View(model);
    }
}

Upvotes: 3

Views: 2891

Answers (3)

Piotr Szmyd
Piotr Szmyd

Reputation: 13366

A cleaner, shorter and much more readable syntax would look like this:

public ActionResult Index(long? id){ 
    using (var ctx = new MainDBContext())
    {
        var entities = ctx.OfflinePayments.Where(e => !e.HasValue || e.Assigned_ID == id.Value);

        var model = entities.Select(e => new EditOfflinePayment { ID = e.ID, Amount = e.Amount }).ToList();
        return View(model);
    }
}

Upvotes: 0

Jon
Jon

Reputation: 437376

If I understand correctly, your problem is that the compiler doesn't let you write where o.Assigned_ID == id in the query.

That's because id is a Nullable<long>, which is not implicitly convertible to a long (which OffLinePayment.Assigned_ID presumably is).

You need to write where o.Assigned_ID == id.Value instead. Take a look at what the Value property does so that you don't get any surprises.

Upvotes: 0

Yahia
Yahia

Reputation: 70369

try

var model = from o in new MainDBContext().OffLinePayments
                   where o.Assigned_ID == id
                    select new EditOffLinePayment 
                    {
                         ID = o.ID,
                        Amount = o.Amount 
                    };

Upvotes: 2

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