Entity Framework: records in child table are not inserting

Question

Records in parent table are saving successfully but child table records are not saving and no error is coming, using Entity Framework with repository pattern available here .

Below is the sample schema design of my tables, might be a special case.

Considering above tables if I try to insert records in Table2 and Table3 together no record inserted into Table3.

Please let me know if need further clarification on the question.

Thanks in advance!!

EDIT 1

Below is the code I am using to insert parent and child records together.

    var parent = new Table2()
    {
        Table1Id = 1,
        SecondColumn = 1
    };

    parent.Tables3.Add(new Table3()
    {
        Table1Id = 1,
        SecondColumn = 1,
        AnotherColumn = 1
    });

    context.Set<Table2>().Attach(parent);
    context.Entry<Table2>(parent).State = EntityState.Added;
    context.SaveChanges();

EDIT 2

public partial class Table2
{
    public Table2()
    {
        this.Tables3 = new HashSet<Table3>();
    }

    public int Table1Id { get; set; }
    public int SecondColumn { get; set; }

    public virtual ICollection<Table3> Tables3 { get; set; }
}

public partial class Table3
{
    public int Table1Id { get; set; }
    public int SecondColumn { get; set; }
    public int AnotherColumn { get; set; }
}

Answer 1

You should do one of two:

1. Use add instead of attach

   var parent = new Table2() { Table1Id = 1, SecondColumn = 1 }; parent.Tables3.Add(new Table3() { Table1Id = 1, SecondColumn = 1, AnotherColumn = 1 }); context.Set<Table2>().Add(parent); context.SaveChanges();

In this case all navigation properties will also be added.

2. Paint your whole graph with state after attach (now you set state only to parent table).