相当于内连接：
{ DELETE t1 FROM tdb_goods AS t1, (SELECT goods_id, goods_name FROM tdb_goods
GROUP BY goods_name HAVING COUNT(goods_name)>1) AS t2
WHERE t1.goods_name = t2.goods_name AND t1.goods_id>t2.goods_id; }
看不懂的同学可以看：http://database.51cto.com/art/201009/225564.htm
mysql> DELIMITER //
mysql> CREATE PROCEDURE removeUserById(IN id INT UNSIGNED)
-> BEGIN
-> DELETE u FROM users AS u WHERE u.id=id;
-> END
-> //
给users一个别名也是可以的啊,没关系
