如何在大型数据库中对2列或更多列求和- c#

using System;
using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        string connectionString = "YourConnectionString"; // 替换为你的数据库连接字符串

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();

            string query = "SELECT SUM(column1) AS sum1, SUM(column2) AS sum2, SUM(column3) AS sum3 FROM YourTable"; // 替换为你的表名和列名

            using (SqlCommand command = new SqlCommand(query, connection))
            {
                using (SqlDataReader reader = command.ExecuteReader())
                {
                    if (reader.Read())
                    {
                        decimal sum1 = reader.GetDecimal(0); // 获取第一列的求和结果
                        decimal sum2 = reader.GetDecimal(1); // 获取第二列的求和结果
                        decimal sum3 = reader.GetDecimal(2); // 获取第三列的求和结果

                        Console.WriteLine("Sum of column1: " + sum1);
                        Console.WriteLine("Sum of column2: " + sum2);
                        Console.WriteLine("Sum of column3: " + sum3);
                    }
                }
            }
        }
    }
}