Question

I have a stored procedure (I cannot edit) that I am calling via linq.

The stored procedure returns values (more complex but important data below):

Customer   Stock Item   Date       Price   Priority  Qty
--------------------------------------------------------
CUST1      TAP         01-04-2012  £30     30        1 - 30
CUST1      TAP         05-04-2012  £33     30        1 - 30
CUST1      TAP         01-04-2012  £29     20        31 - 99
CUST1      TAP         01-04-2012  £28     10        1 - 30

I am trying to limit this list to rows which have unique Dates and unique quantities in LINQ.
I want to remove items with the HIGHER priority leaving rows with unique dates and qty’s.

I have tried several group by‘s using Max and order by‘s but have not been able to get a result.

Is there any way to do this via linq?

EDIT:

Managed to convert brad-rem’s answer into VB.net.

Syntax below if anyone needs it:

returnlist = (From p In returnlist
              Order By p.Qty Ascending, p.Priority
              Group By AllGrp = p.Date, p.Qty Into g = Group
              Select g.First).ToList

Answer 1

How about the following. It groups by Date and Qty and orders it so that the lower priorities come first. Then, it just selects the first item from each group, which are all the lower priority items:

var result = from d in dbData
orderby d.Priority 
group d by new
{
    d.Date,
    d.Qty
} into group1
select group1.First();