mysql 怎么使用游标？

SQL code

create PROCEDURE PRO_TradeToOrder(    p_channel_code varchar(10),     p_date varchar(10) )BEGINdeclare tid varchar(50);DECLARE mycur CURSOR  for SELECT tid FROM top_trades WHERE is_transform = 0 AND status = 'WAIT_SELLER_SEND_GOODS' AND channel_code = p_channel_code and DATE_FORMAT(created,'%Y-%m-%d') = p_date;OPEN  mycur;-- REPEATfetch mycur into  tid; select CONCAT('当前的订单编号为',tid);-- end REPEAT;CLOSE mycur; END

执行后为什么影响行数为0
传入的参数执行sql是有数据的

还有怎么不能用alter来修改存储过程？
每次都要删除再重新创建 太麻烦了

[解决办法]
不能用alter是mysql语法
[解决办法]
你这存储过程完全没必要用游标啊


直接
SELECT CONCAT('当前的订单编号为',tid); FROM top_trades WHERE is_transform = 0 AND status = 'WAIT_SELLER_SEND_GOODS' AND channel_code = p_channel_code and DATE_FORMAT(created,'%Y-%m-%d') = p_date;
[解决办法]
贴建表及插入记录的SQL，怎样调用SP的