MySQL执行语句无厘头错误?报错

使用官方提供的MySQL-Connector-.net 6.6.4连接器，创建如下代码：

①  string connstr = "server=localhost;database=test;uid=root;password= 123";

②  MySqlConnection mysqlConn = new MySqlConnection(connstr);

③  mysqlConn.Open();

④  string commandstr = "set @param = '14';"

⑤  MySqlCommand mysqlcommand = new MySqlCommand(commandstr, mysqlConn);

⑥  mysqlcommand.ExecuteNonQuery();

当执行到语句⑥时，报错：Fatal error encountered during command execution.

这个问题很无厘头，请高手指导！