如何通过一个button来将datagridview中的内容更新到数据库中

Question

我通过datatable来填充数据 但如何将datagridview中的更改后的数据更新到数据库中就不会了。。。

private void Form2_Load(object sender, EventArgs e)
{

        dataGridView1.AllowUserToAddRows = false;

        OleDbConnection conn = new OleDbConnection();
        conn.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;;Data Source=g:\\C#\\windows程序\\MISapp\\MISapp\\em.accdb;";
        try
        {
            OleDbDataAdapter da = new OleDbDataAdapter(@"select * from employee", conn);
            conn.Open();
            DataTable table = new DataTable();
            da.Fill(table);
            dataGridView1.DataSource = table;

        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
        finally
        {
            if (conn.State == ConnectionState.Open)
                conn.Close();
        }

        dataGridView1.UnDo_ReDoInitialize();
    }