class SqlExecutor
    {
        private string connectionString;
        private string commandText;
        private Thread workthread;

        public SqlExecutor(string commandText, string connectionString)
        {
            this.commandText = commandText;
            this.connectionString = connectionString;
        }

        public void DoExecute()
        {
            workthread = new Thread(new ThreadStart(this.ExecuteSql));
            workthread.Start();
        }

        private void ExecuteSql()
        {
            using (DbConnection connection = new SqlConnection(connectionString))
            using (DbCommand command = new SqlCommand())
            {
                connection.Open();
                command.Connection = connection;
                command.CommandText = commandText;
                command.ExecuteNonQuery();
                connection.Close();
            }
            Console.WriteLine("Execute '{0}' completed", commandText);
        }

        public void Join()
        {
            if (workthread != null)
                if (workthread.IsAlive) workthread.Join();
        }
    }

        static void Main(string[] args)
        {
            string connectionString = "你自己的连接串";
            SqlExecutor[] executors = new SqlExecutor[]{
                new SqlExecutor("Select 1", connectionString), 
                new SqlExecutor("Select @@version", connectionString)
            };
            foreach (SqlExecutor executor in executors)
            {
                executor.DoExecute();
            }
            foreach (SqlExecutor executor in executors)
            {
                executor.Join();
            }
            Console.ReadLine();
        }