错误消息"ExecuteNonQuery需要打开且可用的连接。该连接的当前状态为已关闭“

using System;
using System.Data.SqlClient;

public class Program
{
    public static void Main()
    {
        string connectionString = "YourConnectionString";
        string sqlQuery = "YourSQLQuery";

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            try
            {
                connection.Open(); // 打开连接

                SqlCommand command = new SqlCommand(sqlQuery, connection);
                command.ExecuteNonQuery(); // 执行SQL语句

                connection.Close(); // 关闭连接
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error: " + ex.Message);
            }
        }
    }
}