缺少具有一对多关系的子元素

Question

In my code I'm getting back a List<TableA>

TableA class definition

class TableA {

        public int ID { get; set; }
        public virtual List<Child>? Children{ get; set; }

}

Child table has 2 columns: TableAID, and TableBID. The PK is a composite key referencing both of these columns. TableAID is a FK referencing dbo.TableA.ID and TableBID is a FK referencing dbo.TableB.ID

Child class definition:

class Child
    {
        public int TableAID { get; set; }

        public int TableBID { get; set; }

        public virtual TableA TableA { get; set; }

    }

Child table data:

TableAID	TableBID
1	4
1	5
2	4

This is my model setup code:

modelBuilder.Entity<Child>()
                .HasKey(c=> new { c.TableAID, c.TableBID  });


            modelBuilder.Entity<TableA>()
               .HasKey(a => a.ID);

            modelBuilder.Entity<TableA>()
                .HasMany(a => a.Children)
                .WithOne(a => a.TableA)
                .HasForeignKey(a => a.TableAID);

When I retrieve the list of type TableA , I'm getting back 2 TableA elements. For the first element, TableA of ID 1, the Children property has 2 elements in it, which is working as designed. But for the second element, Table A of ID 2, I get back no child elements (empty list), even though there exists a child element that has a TableAID of 2. I can't figure out why this is happening. Does anyone have any advice?

Answer 1

all together should be like this

class TableA {

        public int ID { get; set; }
        public virtual List<Child> Children{ get; set; }

}

class TableB {

        public int ID { get; set; }
        public virtual List<Child> Children{ get; set; }

}

class Child
    {
        public int TableAID { get; set; }

        public int TableBID { get; set; }

        public virtual TableA TableA { get; set; }
        public virtual TableB TableB { get; set; }

    }