SQL语句中的output用法

private void button2_Click(object sender, RoutedEventArgs e)
        {
            using (SqlConnection conn = new SqlConnection("Data Source=XX;Initial Catalog=DBData;User ID=sa;Password=111111"))
            {
                conn.Open();
                
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText = "insert [DBData].[dbo].[T_Student] (Number,Name,Score) output inserted.ID values('012345','LiLei','89')";
                    long id = (long)cmd.ExecuteScalar(); //ExecuteScalar()：执行查询，返回结果集中的第一行的第                                                                                                              一列
                    MessageBox.Show("操作成功: i=" + id.ToString());
                }
            }
            
        }



private void button2_Click(object sender, RoutedEventArgs e)
        {
            using (SqlConnection conn = new SqlConnection("Data Source=XX;Initial Catalog=DBData;User ID=sa;Password=111111"))
            {
                conn.Open();
                
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText = "Select * from [DBData].[dbo].[T_Student] where score<160";
                    using (SqlDataReader reader = cmd.ExecuteReader())
                    {
                        while (reader.Read())
                        {
                            MessageBox.Show(reader.GetString(2));  //获取指定列的字符串的值
                        }
                    }
                }
            }
            
        }


private void button2_Click(object sender, RoutedEventArgs e)
        {
            using (SqlConnection conn = new SqlConnection("Data Source=XX;Initial Catalog=DBData;User ID=sa;Password=111111"))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText = "select * from [DBData].[dbo].[T_Student] where Score<@Score";
                    cmd.Parameters.Add(new SqlParameter("@Score", 80));

                    DataSet dataset = new DataSet();

                    //SqlDataAdapter是一个帮我们把SqlCommand查询结果填充到DataSet中的类
                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                    adapter.Fill(dataset);

                    DataTable dt = dataset.Tables[0];
                }
            }

            MessageBox.Show("操作成功");
            
        }