How do I store unkown IQueryable Result into a list?

AliK 0
Viewed 49

LINQ works fine as follows. Query shortened for problem purpose.

var query = (
             from p in DBContext.Products
             from pp in DBContext.Pricing
             select new { p,pp }
            )

Now lets say I wanted a list of this query so for example:

var query = List<IQueryable<dynamic>>(); //this is what I assumed the return type would be but no.
for(int = 0; i<5;i++)
{
    query = (from .... select new {p,pp})
}

So what is correct return type for query to store queries?

linq c#
2 Answers

Because anonymous types have no public name, it isn't possible to statically declare a variable using an anonymous type directly, but you can use type inference and the var keyword to have the compiler infer the proper type.

Given some extension methods:

public static class ObjectExt {
    public static IQueryable<T> AsIQueryableOfType<T>(this T obj) => default(IQueryable<T>);
    public static List<T> AsListOfType<T>(this T obj) => default(List<T>);
}

Then you can declare a IQueryable<T> or List<T> for any anonymous type by passing in the anonymous type. Since anonymous type properties can't be declared, but just initialized, you must assign an appropriate expression to the properties, I recommend using default:

var ListOfQueries = new { p = default(Product), pp = default(Pricing) }
                        .AsIQueryableOfType()
                        .AsListOfType();

for(int i = 0; i < 5; ++i) {
    ListOfQueries.Add(from .... select new {p,pp});
}
NetMage0

try this one.

var linqdata = new List<Tuple<DBContext.Products,DBContext.Pricing>>();
KomiShao0
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