ef cf linq populate ignored property - linq

Question

I'm sure this has to have been asked before, but I couldn't find a good way to search on it.
I have a class like the following
public class Vendor
{
public int VendorId { get; set; }
public string Name { get; set; }
public int ProductCount { get; set; }
}
I have a configuration class setup like
public class VendorConfiguration : EntityTypeConfiguration<Vendor>
{
public VendorConfiguration()
{
Property(p => p.Name).IsRequired().HasMaxLength(128);
Ignore(v => v.ProductCount);
}
}
Here is the query i use to grab the vendors.
public Vendor[] GetVendors()
{
using (var db = new UbidContext())
{
var query = (from vendor in db.Vendors
select vendor);
return query.ToArray();
}
}
How could I populate ProductCount with a subquery that would look similar to
ProductCount = (from vend in db.VendorProducts
where vend.VendorId == id
select vend).Count()
Is there a way I can add that to the main query, so I'm only making 1 call to the db?
Thanks,
Andrew

Answer 1

I would try it this way:
public Vendor[] GetVendors()
{
using (var db = new UbidContext())
{
var query = from vendor in db.Vendors
join vp in db.VendorProducts
on vendor.VendorId equals vp.VendorId
into vendorProducts
select new
{
Vendor = vendor,
ProductCount = vendorProducts.Count()
};
foreach (var item in query)
item.Vendor.ProductCount = item.ProductCount;
return query.Select(a => a.Vendor).ToArray();
}
}
Problem is that you must project into a non-entity type (anonymous in the example above) and then copy the projected ProductCount value into the projected Vendor item by item before you return it.