C#sql查询if()else()基于结果null？

using System;
using System.Data.SqlClient;

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

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

            string query = "SELECT * FROM YourTable WHERE YourCondition"; // 替换为实际的查询语句和条件

            using (SqlCommand command = new SqlCommand(query, connection))
            {
                using (SqlDataReader reader = command.ExecuteReader())
                {
                    if (reader.HasRows)
                    {
                        // 查询结果不为空
                        while (reader.Read())
                        {
                            // 处理查询结果
                            string column1 = reader.GetString(0);
                            int column2 = reader.GetInt32(1);
                            // ...
                        }
                    }
                    else
                    {
                        // 查询结果为空
                        // 执行其他操作
                    }
                }
            }
        }
    }
}