各位高手帮帮忙啊！“System.Data.SqlClient.SqlDataAdapter”不包含“ExecuteNonQuery”的定义，

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;



public partial class Default34 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindData();
}
}
public void BindData()
{
SqlConnection con = new SqlConnection("Server=.;User ID=sx782369;Pwd=123456;DataBase=sx782369");
SqlDataAdapter scd = new SqlDataAdapter("select * from course2", con);
DataSet ds = new DataSet();
scd.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
GridView1.DataKeyNames = new string[]{ "id" };
}
protected void GridView1_roweditinf(object sender, GridViewEditEventArgs e)
{
GridView1.EditIndex = e.NewEditIndex;
DataBind();
}
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
string bccdID = GridView1.DataKeys[e.RowIndex].Value.ToString();
string bccdName = ((TextBox)(GridView1.Rows[e.RowIndex].Cells[1].Controls[0])).Text.ToString();
string bccdPrice = ((TextBox)(GridView1.Rows[e.RowIndex].Cells[2].Controls[0])).Text.ToString();
string upsql = "update course2 set brccdName='"+bccdName+"',brccdPrice='"+bccdPrice+"' where id='"+bccdID+"'";
bool update = excesql(upsql);
if (update)
{
Response.Write("<script>alert(‘修改成功~’)</script>");
GridView1.EditIndex = -1;
BindData();
}
}
public bool excesql(string strsql)
{
string strcon = @"Server=.;User ID=sx782369;Pwd=123456;DataBase=sx782369";
SqlConnection conn = new SqlConnection(strcon);
SqlDataAdapter scd = new SqlDataAdapter(strsql, conn);
try
{
if (conn.State == System.Data.ConnectionState.Closed)
{
conn.Open();
}
scd.ExecuteNonQuery();
return true;
}
catch
{
return false;
}
finally
{
conn.Close();
}
}
}
scd.ExecuteNonQuery();这句老是报错误。
CS1061: “System.Data.SqlClient.SqlDataAdapter”不包含“ExecuteNonQuery”的定义，并且找不到可接受类型为“System.Data.SqlClient.SqlDataAdapter”的第一个参数的扩展方法“ExecuteNonQuery”(是否缺少 using 指令或程序集引用?)