如何在windows窗体应用程序中将数据库中的值相加

using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        string connectionString = "your_connection_string_here";
        string query = "SELECT SUM(YourColumn) AS Total FROM YourTable";

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            SqlCommand command = new SqlCommand(query, connection);
            connection.Open();

            SqlDataReader reader = command.ExecuteReader();
            if (reader.Read())
            {
                double total = reader.GetDouble(reader.GetOrdinal("Total"));
                MessageBox.Show("Total: " + total);
            }
            reader.Close();
        }
    }
}