Question

I am trying to write a slightly complex LINQ to SQL query.

I have a table called

Fruit (FruitID, FieldOne, FieldTwo)

and

FruitChangeHistory (FruitChangeHIstoryID, FruitID, Date)

What I want to do is return the Fruit list, to the view. But the View model will contain an extra field, LastChangeDate. So like: FruitID, FieldOne, FieldTwo, LastChangedDate

I need to work out how to join on the fruitchangehistory with the fruitid, then sort the dates and return only the latest change date.

This is what I have so far:

var list = from p in EntityFramework.Fruits
join h on EntityFramework.FruitChangHistory
on p.FruitID equals h.FruitID
orderby h.LastChangedDate ascending
select new FruitVM
{
FruitID = p.FruitId,
FieldOne = p.FieldOne,
FieldTwo = p.FieldTwo,
LastChangedDate = h.Date
}

but not quite working as planned.

Anyone can help?

Answer 1

Something like this:

var list = from p in EntityFramework.Fruits
        select new FruitVM
        {
            FruitID = p.FruitId,
            FieldOne = p.FieldOne,
            FieldTwo = p.FieldTwo,
            LastChangedDate = (from h in EntityFramework.FruitChangHistory
                                where p.FruitID == h.FruitID
                                orderby h.LastChangedDate ascending
                                select h.LastChangedDate).FirstOrDefault()
        }