mysql的问题

在这里用union连接两个表进行查询如下：

mysql> select id,firstname,surnname from oldcustomer union select id,firstname,surnname from customer order by id;

结果返回如下的提示：ERROR 1064: You have an error in your SQL syntax near 'union select id,firstname,surnname from customer order by id' at line

这个提示应该是拼写错误啊，好象没有什么错误啊！