Adding different items to DataGridViewComboBoxColumn of each row in a DataGridView

Question

Suppose, I have this DataGridView in my application.
- Child is a combo-box column
- ChildID is a combo-box column

I have some objects named Table which I want to load in the Child-column. Each Table object has a number of Column objects which I want load in ChildID-column.

When I change a Child combo box, ChildID column should automatically change to load appropriate columns from the Table object.

The following code is my attempt:

            // populate the DataGridView
            if (database != null)
            {
                childDataGridView1Column1.Items.Clear();
                dataGridView1.Rows.Clear();

                string firstTableName = database.Tables[0].Name;

                // Loading ComboBox columns              
                int i = 0;
                foreach (Table t in database.Tables)
                {
                    dataGridView1.Rows.Add(true, t.Name, t.PrimaryKeyName);//Set Child's text to "None"
                    dataGridView1.Rows[i].Tag = t;

                    // Load 'Database.Tables' to 'Child' column
                    DataGridViewComboBoxCell dataGridview1ChildComboBoxCell = (DataGridViewComboBoxCell)dataGridView1.Rows[i].Cells[(int)CellNo.Child];
                    dataGridview1ChildComboBoxCell.Items.Clear();
                    foreach (Table t2 in database.Tables)
                    {
                        dataGridview1ChildComboBoxCell.Items.Add(t2.Name);
                    }
                    dataGridView1.Rows[i].Cells[(int)CellNo.Child].Value = firstTableName;

                    // Load 'Table.Columns' to 'ChildID' column
                    DataGridViewComboBoxCell dataGridview1ChildIDComboBoxCell = (DataGridViewComboBoxCell)dataGridView1.Rows[i].Cells[(int)CellNo.ChildID];
                    dataGridview1ChildIDComboBoxCell.Items.Clear();
                    foreach (Column c in t.Columns.Values)
                    {
                        dataGridview1ChildIDComboBoxCell.Items.Add(c.Name);
                    }

                    i++;
                }
            }

    ... ... ...   

    private void dataGridView1_CellValueChanged(object sender, DataGridViewCellEventArgs e)
    {
        //DataGridViewComboBoxCell cb = (DataGridViewComboBoxCell)dataGridView1.Rows[e.RowIndex].Cells[(int)CellNo.Child];
        //if (cb.Value != null)
        {
            // do stuff
            DataGridViewRow row = dataGridView1.SelectedRows[0];
            Table t = row.Tag as Table;

            // Load 'Table.Columns' to 'ChildID' column
            DataGridViewComboBoxCell dataGridview1ChildIDComboBoxCell = (DataGridViewComboBoxCell)row.Cells[(int)CellNo.ChildID];
            dataGridview1ChildIDComboBoxCell.Items.Clear();
            foreach (Column c in t.Columns.Values)
            {
                dataGridview1ChildIDComboBoxCell.Items.Add(c.Name);
            }

            dataGridView1.Invalidate();
        }
    }

But, it doesn't work.