如何获取列的值并放入label C# & SQL Server中

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

namespace YourNamespace
{
    public partial class YourForm : Form
    {
        public YourForm()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string connectionString = "Your SQL Server connection string";
            string query = "SELECT columnName FROM tableName";

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

                using (SqlCommand command = new SqlCommand(query, connection))
                {
                    using (SqlDataReader reader = command.ExecuteReader())
                    {
                        if (reader.Read())
                        {
                            string columnValue = reader.GetString(0);
                            label1.Text = columnValue;
                        }
                    }
                }
            }
        }
    }
}