目录

一.变量

1.系统变量  global session

2.用户自定义变量

3.局部变量

二.触发器

1.pysx函数(销售)拼音缩写触发器

2.goods维护(存储过程)

3.xkglxt

4.订单延期

---

一.变量

1.系统变量  global session

2.用户自定义变量

1.不用提前声明，使用时直接''  @变量名      ''

2.set @name='lisi';

set 字段名 into @name from 表名

3.局部变量

1.需要用declare声明

2.declare 变量名 类型 

3.set 变量名=值

二.触发器

1.pysx函数(销售)拼音缩写触发器

DELIMITER $$USE `shujuku`$$DROP FUNCTION IF EXISTS `PysxCx`$$CREATE DEFINER=`root`@`localhost` FUNCTION `PysxCx`(zw VARCHAR(20)) RETURNS VARCHAR(20) CHARSET utf8mb4READS SQL DATA
BEGINSET @pysx='';SET @l=CHAR_LENGTH(zw);SET @i=1;WHILE (@i<=@l) DOSELECT jp INTO @jp FROM hzpyb  WHERE hz=SUBSTR(zw,@i,1);SET @pysx=CONCAT(@pysx,@jp);SET @i=@i+1;END WHILE;    RETURN @pysx;END$$DELIMITER ;

                                                 触发器维护pysx缩写2

DELIMITER $$USE `shujuku`$$DROP TRIGGER `Update_mcsx_before_insert_goods`$$CREATETRIGGER `Update_mcsx_before_insert_goods` BEFORE INSERT ON `goods` FOR EACH ROW BEGIN   SET new.abbreviations=pysxcx(new.gname);    
END;
$$DELIMITER ;

                                     触发器维护pysx缩写2

DELIMITER $$USE `shujuku`$$DROP TRIGGER `Update_mcsx_before_update_goods_gname`$$CREATETRIGGER `Update_mcsx_before_update_goods_gname` BEFORE UPDATE ON `goods` FOR EACH ROW BEGIN    IF new.gname<>old.gname THEN      SET new.abbreviations=pysxcx(new.gname);     END IF;    
END;
$$DELIMITER ;

2.goods维护(存储过程)

goodswh

DELIMITER $$USE `shujuku`$$DROP PROCEDURE IF EXISTS `goodswh`$$CREATE DEFINER=`root`@`localhost` PROCEDURE `goodswh`(gid INT,gname VARCHAR(20),unit VARCHAR(20),barcode VARCHAR(20),retail_Price DECIMAL(10,2),promotional_Price DECIMAL(10,2),STATUS TINYINT)
BEGINIF gid=0 THENINSERT INTO goods(gname,unit,barcode,retail_Price,promotional_Price,STATUS) VALUES (gname,unit,barcode,retail_Price,promotional_Price,STATUS);ELSEIF gid>0 THENUPDATE  goods SET goods.gname=gname, goods.unit=unit, goods.barcode=barcode, goods.retail_Price=retail_Price, goods.promotional_Price=promotional_Price, goods.STATUS=STATUS WHERE  goods.gid=gid;ELSEDELETE FROM goods WHERE  goods.gid=-gid;END IF;END$$DELIMITER ;

goodscx

DELIMITER $$USE `shujuku`$$DROP PROCEDURE IF EXISTS `goodscx`$$CREATE DEFINER=`root`@`localhost` PROCEDURE `goodscx`(gid INT)
BEGINIF gid=0 THENSELECT * FROM goods;ELSESELECT * FROM goods  WHERE goods.gid=gid;END IF;
END$$DELIMITER ;

 删除触发器

DELIMITER $$USE `shujuku`$$DROP TRIGGER /*!50032 IF EXISTS */ `delete_from_stock_after_delete_goods`$$CREATE/*!50017 DEFINER = 'root'@'localhost' */TRIGGER `delete_from_stock_after_delete_goods` BEFORE DELETE ON `goods` FOR EACH ROW BEGIN	DELETE FROM stock WHERE gid=old.gid;   
END;
$$DELIMITER ;

 11.销售业务存储过程

DELIMITER $$USE `shujuku`$$DROP PROCEDURE IF EXISTS `Xsjlcp_new`$$CREATE DEFINER=`root`@`localhost` PROCEDURE `Xsjlcp_new`(cashierid INT, uid INT, payment TINYINT, xsmx VARCHAR(8000))
BEGINDECLARE amount_money DECIMAL(18,3);DECLARE actual_money DECIMAL(18,3);DECLARE discount_money DECIMAL(18,3);-- 如果存在名为 lsb 的表，则删除它DROP TEMPORARY TABLE IF EXISTS lsb;-- 创建临时表 lsb，包含 gid 和 xssl 两个字段CREATE TEMPORARY TABLE lsb (gid INT, xssl NUMERIC(18,3));-- 使用 WHILE 循环解析 xsmx 中的数据并插入到 lsb 表中WHILE (xsmx > '') DOSET @k = POSITION(',' IN xsmx);SET @gid = LEFT(xsmx, @k - 1);SET xsmx = SUBSTR(xsmx, @k + 1);SET @k = POSITION(',' IN xsmx);SET @xssl = LEFT(xsmx, @k - 1);INSERT INTO lsb(gid, xssl) VALUES(@gid, @xssl);SET xsmx = SUBSTR(xsmx, @k + 1);END WHILE;-- 计算总金额和实际金额SELECT SUM(xssl * retail_Price) INTO amount_money FROM lsb, goods WHERE lsb.gid = goods.gid;SELECT SUM(xssl * promotional_Price) INTO actual_money FROM lsb, goods WHERE lsb.gid = goods.gid;SET discount_money = amount_money - actual_money;-- 插入收银记录到 cashaccount 表INSERT INTO cashaccount(cashierid, uid, payment, amount_money, actual_money, discount_money)VALUES (cashierid, uid, payment, amount_money, actual_money, discount_money);-- 插入销售明细到 cashaccount_detail 表INSERT INTO cashaccount_detail(cashaccountid, gid, salesquantity, retailprice, promotionalprice)SELECT LAST_INSERT_ID(), lsb.gid, xssl, retail_Price, promotional_Price FROM lsb, goods WHERE lsb.gid = goods.gid;-- 更新库存UPDATE stock s JOIN lsb ON s.gid = lsb.gid SET s.quantity = s.quantity - lsb.xssl;-- 如果 uid 大于等于 10000，则更新用户的卡余额和积分IF uid >= 10000 THENUPDATE `user` SET card_balance = card_balance - actual_money, points = points + FLOOR(actual_money)WHERE uid = uid;END IF;-- 删除临时表 lsbDROP TEMPORARY TABLE IF EXISTS lsb;END$$DELIMITER ;

3.xkglxt

1.实现学生表的插入，需要判断当前学号学生是否存在

DELIMITER $$USE `myspj`$$DROP PROCEDURE IF EXISTS `insert_Student`$$CREATE DEFINER=`root`@`localhost` PROCEDURE `insert_Student`(IN Studentid INT ,IN Studentname VARCHAR(10))
BEGINDECLARE StudentExists INT ;SELECT COUNT(*) INTO StudentExistsFROM Student WHERE id=Studentid;IF StudentExists > 0 THEN SELECT '学号存在，学生信息插入失败' ;ELSEINSERT INTO Student(id,`name`) VALUES (Studentid,Studentname);SELECT '学生信息插入成功';END IF;END$$DELIMITER ;

2.实现选课表的插入，需要判断当前课程id和学生id是否存在

DELIMITER $$USE `myspj`$$DROP PROCEDURE IF EXISTS `insert_xuanke`$$CREATE DEFINER=`root`@`localhost` PROCEDURE `insert_xuanke`(IN _xid INT, IN _id INT, IN _kid INT, IN _chengji INT)
BEGIN    DECLARE studentExists INT DEFAULT 0;    DECLARE courseExists INT DEFAULT 0;    SELECT COUNT(*) INTO studentExists   FROM Student WHERE id = _id;    IF studentExists = 0 THEN    SELECT '学生id不存在' AS result;  END IF;  SELECT COUNT(*) INTO courseExists   FROM kecheng WHERE kid = _kid;  IF courseExists = 0 THEN    SELECT '课程id不存在' AS result;  ELSE    -- 检查学生是否已经选了这门课程  IF NOT EXISTS (SELECT 1 FROM xuanke WHERE kid = _kid AND id = _id) THEN    INSERT INTO xuanke (xid, id, kid, chengji) VALUES (_xid, _id, _kid, _chengji);    SELECT '插入成功' AS result;  ELSE    SELECT '学生已选该课程';    END IF;    END IF;  
END$$DELIMITER ;

4.订单延期

将顾客表上余额不足1000元的，将订单日期延后10天

UPDATE orders
SET DATE = DATE_ADD(DATE, INTERVAL 10 DAY)
WHERE orders.gid IN (SELECT gidFROM customersWHERE balance < 1000
);

将商品表中没有顾客订购的商品信息删除

DELETE FROM goods
WHERE goods.`sid` NOT IN (
SELECT DISTINCT orders.`sid` FROM orders
)