先来看段mysql查询文章回复语句：
#查询文章回复
-- ----------------------------
-- Procedure structure for `sp_select_reply_article`
-- ----------------------------
DROP PROCEDURE IF EXISTS `sp_select_reply_article`;
DELIMITER ;;
CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_select_reply_article`(IN `ra_id` int,IN `pagefrom` int,IN `pagesize` int)
BEGIN
#Routine body goes here...
SET @ra_id = ra_id;
SET @pagefrom = pagefrom;
SET @pagesize = pagesize;
SET @ssra = CONCAT('SELECT * FROM gk_article WHERE id = ? LIMIT ?,?');
PREPARE sqlquery FROM @ssra;
EXECUTE sqlquery USING @ra_id,@pagefrom,@pagesize;
END
DELIMITER ;
#技术点1：MySql5.1不支持LIMIT参数（MySql5.5就支持了），如果编写存储过程时使用LIMIT做变量，那是需要用动态SQL来构建的，而这样做性能肯定没有静态SQL好。主要代码如下：
SET @ssra = CONCAT('SELECT * FROM gk_article WHERE id = ? LIMIT ?,?');
PREPARE sqlquery FROM @ssra;
EXECUTE sqlquery USING @ra_id,@pagefrom,@pagesize;
#技术点2：如果同时需要返回受影响行数需要在语句后面添加语句：ROW_COUNT()函数，两条语句之间需要“;”分隔。
#更新数据
-- ----------------------------
-- Procedure structure for `sp_update_permission`
-- ----------------------------
DROP PROCEDURE IF EXISTS `sp_update_permission`;
DELIMITER ;;
CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_update_permission`(IN `puser_uid` varchar(20),IN `plevel` int,IN `ppower` int)
BEGIN
#Routine body goes here...
SET @puser_uid = puser_uid;
SET @plevel = plevel;
SET @ppower = ppower;
UPDATE gk_permission SET `level` = @plevel, power = @ppower WHERE user_uid = CONVERT(@puser_uid USING utf8) COLLATE utf8_unicode_ci;
END
DELIMITER ;
#技术点3：MySQL进行字符串比较时发生错误（Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '='），解决方法：将比较等式一边进行字符串转换，如改为“CONVERT(b.fullCode USING utf8) COLLATE utf8_unicode_ci”，主要代码如下：
