Linq query with a Conditional WHERE Clause

Question

I am new to LINQ so apologises upfront

I have the following Linq query :-

var OrdersByBranches =
    from a in AllOrders
    join b in AllBranchKeys
        on a.BranchKey equals b.BranchKey
    orderby a.Date
    group a by new { a.Date, a.paymentMethod } into BranchOrderGrouped
    select new
    {
        BranchOrderGrouped.Key.Date,
        CurrencyAmount = BranchOrderGrouped.Sum(a =>
        a.CurrencyAmount),
        BranchOrderGrouped.Key.paymentMethod
    };

I need to include a where clause in the above query ... only if a variable called BranchKeySelected is ""

I have tried using an If Else statement and have the same above query duplicated with one containing a where clause and one NOT. ...But When I do this .. then OrdersByBranches is NOT available outside of the IF Statement

Would be grateful for any help

Regards

Ghost

score 7 · Answer 1 · edited Dec 03 '12 at 08:58

7

var OrdersByBranches = 
    from a in AllOrders 
    join b in AllBranchKeys on a.BranchKey equals b.BranchKey 
    orderby a.Date 
    group a by new { a.Date, a.paymentMethod } into BranchOrderGrouped 
    select new { 
        BranchOrderGrouped.Key.Date, 
        CurrencyAmount = BranchOrderGrouped.Sum(a =>  a.CurrencyAmount), 
        BranchOrderGrouped.Key.paymentMethod 
    };

if(string.IsNullOrEmpty(BranchKeySelected ))
{
    OrdersByBranches = OrdersByBranches.Where(/*blbabla*/);
}

return OrdersByBranches;

edited Dec 03 '12 at 08:58

Stephan

4,187
1
21
33

answered May 17 '10 at 14:52

Gregoire

24,219
6
46
73

I think you have the conditional reversed from the question :) – jball May 17 '10 at 14:53
@jball: Maybe it's on purpose, to teach a lesson to people who copy and paste code before reading and understanding it? – Matti Virkkunen May 17 '10 at 14:56
I've a similar problem with dynamical grouping using LINQ. Can you please have a look [here](http://stackoverflow.com/questions/22694680/how-to-use-linq-for-conditional-grouping-and-filtering-on-a-datatable)? – Cheshire Cat Apr 01 '14 at 15:19

score 1 · Answer 2 · edited May 17 '10 at 15:03

1

Try (and my linq is not polished)

var OrdersByBranches = from a in AllOrders 
    join b in AllBranchKeys on a.BranchKey equals b.BranchKey 
    where b.BranchKeySelected.Contains("")
    orderby a.Date group a by new 
        {
            a.Date, 
            a.paymentMethod
        }
        into BranchOrderGrouped
    select new
        {
            BranchOrderGrouped.Key.Date, 
            CurrencyAmount = BranchOrderGrouped.Sum(a =>  a.CurrencyAmount),
            BranchOrderGrouped.Key.paymentMethod 
         };

edited May 17 '10 at 15:03

Pure.Krome

84,693
113
396
647

answered May 17 '10 at 14:58

gnome

1,113
2
11
19

`where b.BranchKeySelected.Contains("")`? Isn't that a typo? It will return `true` on all strings (except `null`). – Steven May 17 '10 at 16:14

Linq query with a Conditional WHERE Clause

2 Answers2

Linked