CODEWITHSUNDEEP
c#winformslinq-to-sqlc#-4.0
Sealer_05
Sealer_05

Reputation: 5566

C# linq2sql selecting multiple columns

I am struggling to select multiple columns in the carCheckouts table. I just want the startMiles and endMiles from one row that I know the pk of. Is my linq statement correct? if so how do I turn b.startMiles and b.endMiles into usable variables after? Thanks

var m = (from b in db.carCheckouts
where b.pk == primaryKey
select new {b.startMiles, b.endMiles});

Upvotes: 0

Views: 198

Answers (4)

antar
antar

Reputation: 510

You can also use

select new {b.startMiles, b.endMiles}).FirstOrDefault();

on your linq statement

Upvotes: 1

undefined
undefined

Reputation: 34238

var m = (from b in db.carCheckouts
where b.pk == primaryKey
select new {b.startMiles, b.endMiles});

double totalMiles;

foreach(var item in m)
{
    totalMiles = item.endMiles - item.startMiles;
}

Upvotes: 2

BrokenGlass
BrokenGlass

Reputation: 160852

Your current query returns an IQueryable of an anonymous type - but it sounds like you want a single item:

var m = (from b in db.carCheckouts
where b.pk == primaryKey
select new {b.startMiles, b.endMiles}).Single();

Now you can use the properties of m just so:

Console.WriteLine("Start Miles:"  + m.startMiles);

Upvotes: 3

Mark W
Mark W

Reputation: 3909

You've turned m into an anonymous type (actually m will be an IQueryable<> of that anon type) that can be used anywhere inside the scope it's declared. Anon types were added to allow something like this so you don't have pre-create a type that would hold these values, you create the type on the fly.

If you want to only have 1 and not an IQueryable you can do .FirstOrDefault or just .First to give you the 1 instance of that anon type.

Upvotes: 2

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