c# – 如何从数据集中设置DataGridViewComboBoxColumn值

work_hours
 work_hours_id | date  | _project_id
     1            1.2.      10
     2            1.2.      11
     3            1.2.      10 

 project
 project_id | project_name
    10           pr1
    11           pr2
    12           pr3

在DataGridView中我想看到这个：

work_hours_id | date | _person_id | project_name(DataGridViewComboBoxColumn)
     1            1.2.     10            pr1
     2            1.2.     11            pr2
     3            1.2.     10            pr1

我怎么能这样做？
2.如果我使用SqlCommandBuilder将pr1(work_hours_id = 3)更改为pr3(DataGridViewComboBoxColumn),是否可以保存表work_hours中的更改？

string query = "SELECT work_hours.work_hours_id,work_hours.date FROM work_hours
           LEFT OUTER JOIN project ON work_hours._project_id = project.project_id ORDER BY work_hours.date;
         SELECT * FROM project ORDER BY project_name";

            SqlCommand sqlcmd = new SqlCommand(query,conn);
            da = new SqlDataAdapter(query,connectionString);
            cBuilder = new SqlCommandBuilder(da);
            dt = new DataTable();
            ds = new DataSet();
            da.Fill(dt);
            da.Fill(ds);

            DataGridViewComboBoxColumn columnCb = new DataGridViewComboBoxColumn();
            columnCb.DataPropertyName = "_project_id";

            columnCb.DataSource = ds.Tables[1];
            columnCb.ValueMember = "project_id";
            columnCb.DisplayMember = "project_name";

            bSource = new BindingSource();
            bSource.DataSource = dt;
            dataGridView1.DataSource = bSource;
            dataGridView1.Columns.Add(columnCb);