用WebService实现对数据库进行操作(添加+删除+修改)

表为User，字段有 编号： int id，用户名：string UserName，密码：string UserPwd
   /// <summary>
    /// 添加      
    /// </summary>
    /// <param name="name">用户名</param>
    /// <param name="pwd">密码</param>
    /// <returns></returns>
    [WebMethod]
    public int Add(string name,string pwd)
    {
        sqlConnection conn = new sqlConnection("连接字符串");
        conn.open();
        string sql = "intsert into User (UserName,UsersPwd) values(@UserName,@UsersPwd)";
        sqlCommand cmd = new sqlCommand(sql,conn);
        sqlParameter parn = new sqlParameter("@UserName",name);
        cmd.Parameters.Add(parn);
        sqlParameter parp = new sqlParameter("@UsersPwd",pwd);
        cmd.Parameters.Add(parp);
        int result = cmd.ExecuteNonQuery();
        conn.Close();
        cmd.dispose();
        return result;
    }

    /// <summary>
    /// 修改
    /// </summary>
    /// <param name="name">用户名</param>
    /// <param name="pwd">密码</param>
    /// <param name="id">编号</param>
    /// <returns></returns>
    [WebMethod]
    public int Update(string name,string pwd,int id)
    {
        sqlConnection conn = new sqlConnection("连接字符串");
        conn.open();
        string sql = "update User set UserName=@UserName,UsersPwd=@UsersPwd where id=@id";
        sqlCommand cmd = new sqlCommand(sql,pwd);
        cmd.Parameters.Add(parp);
        sqlParameter pari = new sqlParameter("@id",id);
        cmd.Parameters.Add(pari);
        int result = cmd.ExecuteNonQuery();
        conn.Close();
        cmd.dispose();
        return result;
    }

    /// <summary>
    /// 删除
    /// </summary>
    /// <param name="id">编号</param>
    /// <returns></returns>
    [WebMethod]
    public int Delete(int id)
    {
        sqlConnection conn = new sqlConnection("连接字符串");
        conn.open();
        string sql = "delete from User where id=@id";
        sqlCommand cmd = new sqlCommand(sql,conn);        
        sqlParameter pari = new sqlParameter("@id",id);
        cmd.Parameters.Add(pari);
        int result = cmd.ExecuteNonQuery();
        conn.Close();
        cmd.dispose();
        return result;
    }