之前總是在MSSQL上寫存儲過程，沒有在MYSQL上寫過，也基本沒有用過，今天需要用到MYSQL，研究了下，把項目的需要的存儲過程寫了一部分，寫一下工作總結。這里沒有給出數據庫結構，不討論SQL語句的細節，主要探討存儲過程語法，適合有基礎的人。

先來看段mysql查詢文章回復語句：

#查詢文章回復
-- ----------------------------
-- 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 ;

#技術點1：MySql5.1不支持LIMIT參數（MySql5.5就支持了），如果編寫存儲過程時使用LIMIT做變量，那是需要用動態SQL來構建的，而這樣做性能肯定沒有靜態SQL好。主要代碼如下：

 SET @ssra = CONCAT('SELECT * FROM gk_article WHERE id = ? LIMIT ?,?');
 PREPARE sqlquery FROM @ssra;
 EXECUTE sqlquery USING @ra_id,@pagefrom,@pagesize;
 

#更新數據
-- ----------------------------
-- 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 ;

#技術點3：MySQL進行字符串比較時發生錯誤（Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '='），解決方法：將比較等式一邊進行字符串轉換，如改為“CONVERT(b.fullCode USING utf8) COLLATE utf8_unicode_ci”，主要代碼如下：

 UPDATE gk_permission SET `level` = @plevel, power = @ppower WHERE user_uid = CONVERT(@puser_uid USING utf8) COLLATE     utf8_unicode_ci;
 

#插入數據
-- ----------------------------
-- Procedure structure for `sp_insert_user`
-- ----------------------------
DROP PROCEDURE IF EXISTS `sp_insert_user`;
DELIMITER ;;
CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_insert_user`(IN `uid` varchar(20),IN `upw` varchar(32),IN `name` varchar(20),IN `sex` int,IN `phone` varchar(20),IN `u_id` int,IN `s_id` int,IN `j_id` int)
BEGIN
 #Routine body goes here...
 SET @uid = uid;
 SET @upw = upw;
 SET @uname = uname;
 SET @sex = sex;
 SET @phone = phone;
 #由于外鍵約束，所以添加的外鍵字段需要在對應外鍵所在表有相應數據
 SET @u_id = u_id;
 SET @s_id = s_id;
 SET @j_id = j_id;
 SET @verifytime = DATE('0000-00-00');
 INSERT INTO gk_user(uid,upw,uname,sex,phone,u_id,s_id,j_id,verifytime)
　　　　　　　VALUES(@uid,@upw,@uname,@sex,@phone,@u_id,@s_id,@j_id,@verifytime);
 #查詢結果會自動返回受影響行數
END

DELIMITER ;

#根據ID刪除數據
-- ----------------------------
-- Procedure structure for `sp_delete_exchange_by_id`
-- ----------------------------
DROP PROCEDURE IF EXISTS `sp_delete_exchange_by_id`;
DELIMITER ;;
CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_delete_exchange_by_id`(IN `eid` int)
BEGIN
 #Routine body goes here...
 SET @eid = eid;
 DELETE FROM gk_exchange WHERE id = @eid;
END

DELIMITER ;

#通過賬號查詢用戶或者管理員
-- ----------------------------
-- Procedure structure for `sp_select_user_by_uid`
-- ----------------------------
DROP PROCEDURE IF EXISTS `sp_select_user_by_uid`;
DELIMITER ;;
CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_select_user_by_uid`(IN `uid` varchar(20),IN `getAdmin` int)
BEGIN
 #Routine body goes here...
 SET @uid = uid;
 #SET @getadmin = getAdmin;
 #查詢管理員
 IF (getAdmin = 1) THEN
SELECT us.*, un.`name`, se.`name`, jo.`name`, pe.`level`, pe.power FROM gk_user AS us, gk_unit AS un, gk_section AS se, gk_jobtitle AS jo, gk_permission AS pe WHERE us.u_id = un.id AND us.s_id = se.id AND us.j_id = jo.id AND us.uid = pe.user_uid AND us.uid = CONVERT(@uid USING utf8) COLLATE utf8_unicode_ci;
 END IF;
 #查詢用戶
 IF (getAdmin = 0) THEN
SELECT us.*, un.`name`, se.`name`, jo.`name` FROM gk_user AS us, gk_unit AS un, gk_section AS se, gk_jobtitle AS jo WHERE us.u_id = un.id AND us.s_id = se.id AND us.j_id = jo.id AND us.uid = CONVERT(@uid USING utf8) COLLATE utf8_unicode_ci;
 END IF;
END

DELIMITER ;

#技術點4：這個存數過程需要用到控制語句（if else elseif while loop repeat leave iterate）。

 IF (getAdmin = 1) THEN
#語句…
 END IF;
 

#技術點5：在傳入參數不匹配的情況下報錯（Column count doesn't match value count at row 1），這個就是細心問題了，詳細檢查參數吧。

#技術點6：獲取當前時間的函數：NOW()

#技術點7：“`”這個符號是反單引號，兩個反單引號夾起來的會被當做變量，一般是在定義字段時遇到關鍵字沖突的時候會用到。