how to convert sql union to linq

Question

I have the following Transact SQL query using a union. I need some pointers as to how this would look in LINQ i.e some examples wouldbe nice or if anyone can recommend a goo

Answer 1

There are the 101 Linq Samples - with two union samples Union1 and Union2

This Linq statement should get you the same results as your SQL: (it has for me on a test record-set)

var results = (from a in (from d in DiscountPromotions
            group d by d.BarCode into g
            select new { 
                BarCode = g.Key,
                AmountTaken = g.Sum(p => p.AmountTaken)
                }).Union(from i in ItemSaleTransactions
            group i by i.BarCode into o
            select new { 
                BarCode = o.Key,
                AmountTaken = o.Sum(i => i.AmountTaken)
                }) group a by a.BarCode into b
                select new {
                    BarCode = b.Key,
                    AmountTaken = b.Sum(c => c.AmountTaken)
                });