private void Form1_Load(object sender, EventArgs e)
        {
            string querystring = "select 编号,上课地点 from 课程表";
           string connstring ="server=(local);uid=sa;pwd=ccxx;database=eisbook"; 
            using(SqlConnection conn=new SqlConnection(connstring))
            {
                conn.Open();
               
                SqlDataAdapter da = new SqlDataAdapter(querystring, connstring);
                DataSet ds = new DataSet();
                da.Fill(ds, "lessons");
                              for (int i = 0; i < ds.Tables[0].Rows.Count;i++ )
                {
                    listView1.Items.Add(ds.Tables["lessons"].Columns[0].ToString(),ds.Tables["lessons"].Columns[1].ToString());
                }
            }
               }