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Question

We are using EF .NET core for our architecture and want to do a basic query. So all we are after is using both LINQ & EF with lazy loading switched off to select the parent, in this case stick item and some of the fields in the child objects. Then return them back into our strongly typed item.

Something like this.

 var qry = _context.Set<stock>()
        .Include(p => p.stockitem)
        .Where(q => q.customer == accountNo)
        .Select(r => new stock() { 
            customer = r.customer, 
            r.stockitem.select(s => new {id, s.id, s.name }})
        .ToList();

So is it possible to do this? basically get hold of say just a couple of columns from our child object. Then have everything returned in the strongly typed object.

Answer 1

First create a model in which the selected data will be stored (This model is just an example):

public class MyNewCustomer
{
    public string CustomerAccount { get; set; }
    public Dictionary<int, string> Items { get; set; }
}

After that you can create a new object from your select:

var data = _context.Stocks
    .Include(p => p.stockitem)
    .Where(p => p.customer == accountNo)
    .Select(p => new MyNewCustomer 
    {
        CustomerAccount = p.customer,
        Items = p.stockitem.ToDictionary(s => s.id, s => s.name)
    }).ToList();

PS: I used Dictionary because you didn't provide the actual model. You can choose whatever kind of List<TObject> you want.