我有一个名为appmondb的数据库，我想使用组合框来切换表。如果我先选择ids表，这没有问题，但如果我接下来选择accounts表，id和accounts字段将同时出现。

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
        currentdt.Clear();//clear table 
        dataGridView1.DataSource = null;

        MySqlDataAdapter adapter = new MySqlDataAdapter();
        MySqlCommand cmd;
        string sql = "SELECT * FROM " + comboBox1.Text;

        cmd = new MySqlCommand(sql, Connection.connMaster);

        adapter.SelectCommand = cmd;
        adapter.Fill(currentdt);

        dataGridView1.DataSource = currentdt;
        totalPage = calculateTotalPages(currentdt);//update totalPage
}

first I choose ids table
after that, I select accounts table
我有话要说应该是.fill（）或者dataset和datatable的措辞