CODEWITHSUNDEEP
c#linq
Ninja In Pajamas
Ninja In Pajamas

Reputation: 97

for loop in where clause

I am trying to calculate value through LINQ with two conditions, one of which happens to contain a foreach loop.

I've a list of integers statusList (stores StatCatId)

And based on the values in this list I want to add a where condition in my LINQ statement.

 var sListings = (from l in _colMgr.Listings.Values.AsEnumerable()
                                 where (l.SystemPrice ?? 0) > 0 &&
 // Need to add condition like foreach(s in statusList) if l.StatCatId == s
                                 select l).ToList();

Upvotes: 0

Views: 146

Answers (3)

Grundy
Grundy

Reputation: 13381

Yet another way with join clause

var sListings = 
(
    from l in _colMgr.Listings.Values.AsEnumerable()
    join s in statusList on l.StatCatId equals s
    where (l.SystemPrice ?? 0) > 0
    select l
).ToList();

Upvotes: 2

Darek
Darek

Reputation: 4797

Depending on the complexity of your calculation, you might use Contains, SelectMany, Sum, etc. , or plug in your own Func into your LINQ call.

class Program
{
    static void Main(string[] args)
    {
        var data = new List<DataPoint>
                   {
                       new DataPoint(){Condition = true, Value = 0, Values = new List<int>{1,2,3}},
                       new DataPoint(){Condition = false, Value = 10, Values = new List<int>{}},
                       new DataPoint(){Condition = true, Value = 0, Values = new List<int>{4,5}},
                       new DataPoint(){Condition = false, Value = 20, Values = new List<int>{}}
                   };
        var sum = data.Sum(s=>s.Condition?s.Values.Sum():s.Value);
    }
}

internal class DataPoint
{
    public bool Condition { get; set; }

    public int  Value { get; set; }

    public List<int> Values { get; set; }
}

or with an Func<>

Func<DataPoint, int> func = point => point.Condition ? point.Values.Sum() : point.Value;
var sum = data.Sum(s => func(s));

or if Func needs multiple steps:

        Func<DataPoint, int> func = point =>
        {
            var retValue = point.Condition ? point.Values.Sum() : point.Value;
            return retValue;
        };
        var sum = data.Sum(s => func(s));

Upvotes: 0

Douglas
Douglas

Reputation: 54887

You might be looking for the Contains method:

var sListings = 
(
    from l in _colMgr.Listings.Values.AsEnumerable()
    where (l.SystemPrice ?? 0) > 0
       && statusList.Contains(l.StatCatId)
    select l
).ToList();

Upvotes: 4

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