使用linq在相关表中选择Entity属性

Question

here is my setup.

Base Model

public class Base
{
    public int BaseID { get; set; }
    [StringLength(8)]
    [Index(IsUnique = true)]
    public string BaseNumber { get; set; }
    public ICollection<BillOfMaterial> billOfMaterials { get; set; }
}

BillOfMaterial Model

public class BillOfMaterial
{
    public int BillOfMaterialID { get; set; }
    [StringLength(10)]
    [Index(IsUnique = true)]
    public string BomNumber { get; set; }
    public ICollection<Base> Bases { get; set; }
}

What I am trying to do is select all bill of material BomNumbers where the base is equal to a input base number.

What I have tried

BaseNumber = "A1C1D001";

var BOMQuery = (from Base in db.Bases.Include("BillOfMaterials")
                where Base.BaseNumber == BaseNumber
                select Base.billOfMaterials.ToList());

When trying to create this query I can't see the BomNumber property when I do => select Base.BillOfMaterials.(Can't Find Property)

I tried using the .Include() extension to try and bring in the related table in hopes it would give me the property. Not sure how to word this question exactly to do a good google search for the answer. What am I doing wrong here? Any help would be appreciated.

Thank you,

Answer 1

When you only need a list of BOMs use the following:

var BOMQuery = db.Bases
              .Where(x => x.BaseNumber == BaseNumber)
              .SelectMany(a => a.billOfMaterials.Select(b => b.BomNumber)).ToList();

You can then add it to an ObservableCollection like this:

BomList = new ObservableCollection<string>(BOMQuery);