Compare the price of each line and the average price of this type of line, use subquery and exists to obtain the number of lines respectively

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Statement of needs:

Compare the price of each line and the average price of that type of line

Use sub-query and exists to obtain the line type information with the number of lines exceeding the number of "outbound travel" lines. It is required to display the line type number and line number in ascending order of the number of lines

Realization ideas:

Demand description (1) solution ideas

  • Display the average price of the type of the current line in the from clause

Demand description (2) solution ideas

  • Single-line subquery: get the line type number named "outbound travel" from the line type table
  • Multi-line sub-query: use count (line number) to get the number of "outbound travel" routes from the itinerary table, and the line type number obtained from the single-line sub-query as the comparison condition
  • Main query: In the route table, group by route type number, use count (route number) to calculate the number of different types of routes, and use the having clause to limit the grouping data, which will be obtained from the multi-row subquery. The number of “outbound travel” routes as a restriction

Implementation code:

Compare the price of each line and the average price of that type of line

SELECT A.lineTypeID 类型,lineName 线路名,price 价格,该线路类型平均价格 FROM line A,
(SELECT lineTypeID, AVG(price) 该线路类型平均价格 FROM line GROUP BY lineTypeID) B
WHERE A.lineTypeID=B.lineTypeID;

Use sub-query and exists to obtain the line type information with the number of lines exceeding the number of "outbound travel" lines. It is required to display the line type number and line number in ascending order of the number of lines

SELECT lineTypeID 线路类型编号 ,COUNT(lineID) 线路数 FROM line GROUP BY lineTypeID
HAVING COUNT(lineID)>(SELECT COUNT(lineID) FROM line WHERE lineTypeID=
(SELECT lineTypeID FROM lineType WHERE typeName='出境游'));

database:

/*
Navicat MySQL Data Transfer

Source Server         : mysql-1
Source Server Version : 50624
Source Host           : localhost:3306
Source Database       : journey

Target Server Type    : MYSQL
Target Server Version : 50624
File Encoding         : 65001

Date: 2019-01-26 11:19:38
*/

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for `customer`
-- ----------------------------
DROP TABLE IF EXISTS `customer`;
CREATE TABLE `customer` (
  `customerID` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) NOT NULL,
  `gender` varchar(50) DEFAULT NULL,
  `identityID` varchar(18) DEFAULT NULL,
  `tel` varchar(18) DEFAULT NULL,
  PRIMARY KEY (`customerID`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of customer
-- ----------------------------
INSERT INTO `customer` VALUES ('1', '魏国兰', '女', '420103198309125344', '13923561234');
INSERT INTO `customer` VALUES ('2', '刘亚蒙', '男', '420105197610200916', '13867893421');
INSERT INTO `customer` VALUES ('3', '郝琼琼', '女', '420104198703125881', '15902712563');
INSERT INTO `customer` VALUES ('4', '雷亚波', '男', '420103199806195830', '13686035678');
INSERT INTO `customer` VALUES ('5', '李慧娟', '女', '420106199208113738', '13798235671');

-- ----------------------------
-- Table structure for `line`
-- ----------------------------
DROP TABLE IF EXISTS `line`;
CREATE TABLE `line` (
  `lineID` int(11) NOT NULL AUTO_INCREMENT,
  `lineTypeID` int(11) DEFAULT NULL,
  `lineName` varchar(50) NOT NULL,
  `days` int(11) DEFAULT NULL,
  `price` decimal(10,2) DEFAULT NULL,
  `vehicle` char(10) DEFAULT NULL,
  `hotel` char(10) DEFAULT NULL,
  `hasMeal` char(2) DEFAULT NULL,
  PRIMARY KEY (`lineID`)
) ENGINE=InnoDB AUTO_INCREMENT=22 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of line
-- ----------------------------
INSERT INTO `line` VALUES ('1', '1', '黄陂木兰天池', '1', '159.00', '大巴', '无', '无');
INSERT INTO `line` VALUES ('2', '1', '大别山天堂寨', '2', '429.00', '大巴', '二星级', '无');
INSERT INTO `line` VALUES ('5', '1', '恩施大峡谷', '4', '1089.00', '火车卧铺', '二星级', '无');
INSERT INTO `line` VALUES ('6', '1', '庐山', '2', '729.00', '大巴', '二星级', '含');
INSERT INTO `line` VALUES ('7', '1', '凤凰古城', '3', '959.00', '火车卧铺', '二星级', '含');
INSERT INTO `line` VALUES ('8', '1', '黄山', '3', '1099.00', '动车', '三星级', '含');
INSERT INTO `line` VALUES ('9', '2', '海南岛三亚', '5', '3868.00', '飞机', '三星级', '含');
INSERT INTO `line` VALUES ('10', '2', '青岛蓬莱', '4', '2680.00', '飞机', '三星级', '含');
INSERT INTO `line` VALUES ('12', '2', '桂林', '5', '1920.00', '火车卧铺', '二星级', '无');
INSERT INTO `line` VALUES ('13', '2', '华东五市', '6', '2856.00', '动车', '三星级', '含');
INSERT INTO `line` VALUES ('14', '2', '成都九寨沟', '7', '4500.00', '飞机', '三星级', '含');
INSERT INTO `line` VALUES ('15', '2', '西安', '4', '2180.00', '动车', '三星级', '无');
INSERT INTO `line` VALUES ('16', '3', '欧洲德法意瑞', '13', '12294.91', '飞机', '四星级', '含');
INSERT INTO `line` VALUES ('17', '3', '日本东京富士山', '6', '7119.09', '飞机', '三星级', '含');
INSERT INTO `line` VALUES ('18', '3', '新马泰', '8', '6058.80', '飞机', '三星级', '含');
INSERT INTO `line` VALUES ('19', '3', '美国夏威夷', '6', '11493.90', '飞机', '四星级', '无');
INSERT INTO `line` VALUES ('20', null, '梁子湖游', '1', '168.00', '大巴', '无', '无');
INSERT INTO `line` VALUES ('21', null, '洪湖游', '1', '128.00', '大巴', '无', '无');

-- ----------------------------
-- Table structure for `linetype`
-- ----------------------------
DROP TABLE IF EXISTS `linetype`;
CREATE TABLE `linetype` (
  `lineTypeID` int(11) NOT NULL AUTO_INCREMENT,
  `typeName` varchar(50) DEFAULT NULL,
  PRIMARY KEY (`lineTypeID`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of linetype
-- ----------------------------
INSERT INTO `linetype` VALUES ('1', '国内短线游');
INSERT INTO `linetype` VALUES ('2', '国内长线游');
INSERT INTO `linetype` VALUES ('3', '出境游');

-- ----------------------------
-- Table structure for `oc_detail`
-- ----------------------------
DROP TABLE IF EXISTS `oc_detail`;
CREATE TABLE `oc_detail` (
  `travelCustomerID` int(11) NOT NULL,
  `ordersID` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of oc_detail
-- ----------------------------
INSERT INTO `oc_detail` VALUES ('1', '1');
INSERT INTO `oc_detail` VALUES ('1', '2');
INSERT INTO `oc_detail` VALUES ('2', '3');
INSERT INTO `oc_detail` VALUES ('2', '5');
INSERT INTO `oc_detail` VALUES ('2', '7');
INSERT INTO `oc_detail` VALUES ('3', '3');
INSERT INTO `oc_detail` VALUES ('3', '4');
INSERT INTO `oc_detail` VALUES ('3', '7');
INSERT INTO `oc_detail` VALUES ('4', '3');
INSERT INTO `oc_detail` VALUES ('4', '5');
INSERT INTO `oc_detail` VALUES ('4', '8');
INSERT INTO `oc_detail` VALUES ('4', '9');
INSERT INTO `oc_detail` VALUES ('5', '1');
INSERT INTO `oc_detail` VALUES ('5', '6');

-- ----------------------------
-- Table structure for `ol_detail`
-- ----------------------------
DROP TABLE IF EXISTS `ol_detail`;
CREATE TABLE `ol_detail` (
  `ordersID` int(11) NOT NULL,
  `lineID` int(11) NOT NULL,
  `travelDate` date DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of ol_detail
-- ----------------------------
INSERT INTO `ol_detail` VALUES ('1', '2', '2018-10-27');
INSERT INTO `ol_detail` VALUES ('2', '5', '2018-01-20');
INSERT INTO `ol_detail` VALUES ('2', '7', '2018-02-01');
INSERT INTO `ol_detail` VALUES ('3', '1', '2018-06-26');
INSERT INTO `ol_detail` VALUES ('3', '6', '2018-07-05');
INSERT INTO `ol_detail` VALUES ('4', '13', '2018-08-29');
INSERT INTO `ol_detail` VALUES ('5', '1', '2018-10-16');
INSERT INTO `ol_detail` VALUES ('5', '14', '2018-10-21');
INSERT INTO `ol_detail` VALUES ('6', '18', '2018-07-10');
INSERT INTO `ol_detail` VALUES ('7', '15', '2018-10-19');
INSERT INTO `ol_detail` VALUES ('8', '19', '2018-11-27');
INSERT INTO `ol_detail` VALUES ('9', '7', '2018-12-28');

-- ----------------------------
-- Table structure for `orders`
-- ----------------------------
DROP TABLE IF EXISTS `orders`;
CREATE TABLE `orders` (
  `ordersID` int(11) NOT NULL AUTO_INCREMENT,
  `customerID` int(11) DEFAULT NULL,
  `ordersDate` date DEFAULT NULL,
  `amount` decimal(8,2) DEFAULT NULL,
  `man_times` int(11) DEFAULT NULL,
  `discount` decimal(8,2) DEFAULT NULL,
  `effectiveAmount` decimal(8,2) DEFAULT NULL,
  PRIMARY KEY (`ordersID`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of orders
-- ----------------------------
INSERT INTO `orders` VALUES ('1', '1', '2018-10-20', '798.00', '2', '0.98', '782.04');
INSERT INTO `orders` VALUES ('2', '1', '2018-01-15', '1898.00', '2', '0.98', '1860.04');
INSERT INTO `orders` VALUES ('3', '2', '2018-06-18', '2574.00', '6', '0.96', '2471.04');
INSERT INTO `orders` VALUES ('4', '3', '2018-08-21', '2856.00', '1', '1.00', '2856.00');
INSERT INTO `orders` VALUES ('5', '4', '2018-10-10', '7698.00', '4', '0.96', '7390.08');
INSERT INTO `orders` VALUES ('6', '5', '2018-06-23', '6732.00', '1', '1.00', '6732.00');
INSERT INTO `orders` VALUES ('7', '3', '2018-10-11', '4360.00', '2', '0.98', '4272.80');
INSERT INTO `orders` VALUES ('8', '4', '2018-11-21', '12771.00', '1', '1.00', '12771.00');
INSERT INTO `orders` VALUES ('9', '4', '2013-12-20', '899.00', '1', '0.98', '881.02');

-- ----------------------------
-- View structure for `v_customer_orderline_detail`
-- ----------------------------
DROP VIEW IF EXISTS `v_customer_orderline_detail`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`127.0.0.1` SQL SECURITY DEFINER VIEW `v_customer_orderline_detail` AS select `c`.`name` AS `客户名`,`l`.`lineName` AS `线路名`,`l`.`days` AS `行程天数`,`l`.`price` AS `价格` from (((`customer` `c` join `oc_detail` `ocd`) join `ol_detail` `old`) join `line` `l`) where ((`c`.`customerID` = `ocd`.`travelCustomerID`) and (`ocd`.`ordersID` = `old`.`ordersID`) and (`old`.`lineID` = `l`.`lineID`)) ;

-- ----------------------------
-- View structure for `v_customer_orders_detail`
-- ----------------------------
DROP VIEW IF EXISTS `v_customer_orders_detail`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`127.0.0.1` SQL SECURITY DEFINER VIEW `v_customer_orders_detail` AS select `c`.`name` AS `name`,`l`.`lineName` AS `lineName`,`l`.`days` AS `days`,`l`.`price` AS `price` from (((`customer` `c` join `oc_detail` `ocd`) join `ol_detail` `old`) join `line` `l`) where ((`c`.`customerID` = `ocd`.`travelCustomerID`) and (`ocd`.`ordersID` = `old`.`ordersID`) and (`old`.`lineID` = `l`.`lineID`)) ;

-- ----------------------------
-- View structure for `v_nums_line`
-- ----------------------------
DROP VIEW IF EXISTS `v_nums_line`;
CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`127.0.0.1` SQL SECURITY DEFINER VIEW `v_nums_line` AS select `l`.`lineName` AS `线路`,count(`old`.`lineID`) AS `预订数` from (`line` `l` join `ol_detail` `old`) where (`l`.`lineID` = `old`.`lineID`) group by `l`.`lineName` ;

-- ----------------------------
-- Procedure structure for `proc_adjust_price`
-- ----------------------------
DROP PROCEDURE IF EXISTS `proc_adjust_price`;
DELIMITER ;;
CREATE DEFINER=`root`@`127.0.0.1` PROCEDURE `proc_adjust_price`(
		out oldPrice decimal,   -- 原价
		out newPrice decimal,   -- 现价
		out lineName_maxPrice varchar(50) -- 价格最高国内长线游线路名
)
    MODIFIES SQL DATA
begin
		declare lineID_maxPrice int; -- 价格最高国内长线游线路编号
		select max(price) into oldPrice from line where lineTypeID=
			(select lineTypeID from linetype where typeName='国内长线游');
		select lineID, lineName into lineID_maxPrice, lineName_maxPrice from line 
			where price=oldPrice and lineTypeID=(select lineTypeID from linetype where typeName='国内长线游');
		if oldPrice<3000 then
			set newPrice=oldPrice;
		elseif oldPrice>=3000 and oldPrice<4000 then
			set newPrice=oldPrice*0.95;
		elseif oldPrice>=4000 and oldPrice<5000 then
			set newPrice=oldPrice*0.93;
		else
			set newPrice=oldPrice*0.90;
		end if;
		if newPrice<>oldPrice then
			update line set price=newPrice where lineID=lineID_maxPrice;
		end if;
end
;;
DELIMITER ;

-- ----------------------------
-- Procedure structure for `proc_deleteLineType`
-- ----------------------------
DROP PROCEDURE IF EXISTS `proc_deleteLineType`;
DELIMITER ;;
CREATE DEFINER=`root`@`127.0.0.1` PROCEDURE `proc_deleteLineType`(
		_typeName varchar(20) -- 线路类型名称
)
    MODIFIES SQL DATA
begin
		declare state varchar(20);
		declare _lineTypeID int;   -- 线路类型编号
		-- 定义错误处理
		declare continue handler for sqlexception set state='error';
		select lineTypeID into _lineTypeID from LineType where typeName=_typeName;
		-- 开启事务
start transaction;
		-- 将线路中所需要删除的线路类型的编号置为NULL
		update line set lineTypeID=NULL where lineTypeID=_lineTypeID;
		if(state='error') then
			select '线路信息修改失败';
			rollback;
		else
			delete from LineType where typeName=_typeName;
			if(state='error') then
				select '线路类型删除失败';
				rollback;
			else
				select '线路类型删除成功';
				commit;
			end if;
		end if;
end
;;
DELIMITER ;

-- ----------------------------
-- Procedure structure for `proc_LineDetail`
-- ----------------------------
DROP PROCEDURE IF EXISTS `proc_LineDetail`;
DELIMITER ;;
CREATE DEFINER=`root`@`127.0.0.1` PROCEDURE `proc_LineDetail`(
		_lineName varchar(20)
)
    READS SQL DATA
begin
	select lineName 线路名, days 行程天数, price 价格, vehicle 交通工具, hotel 住宿标准 
	from line where lineName=_lineName;
end
;;
DELIMITER ;

-- ----------------------------
-- Procedure structure for `proc_LineNumsRate`
-- ----------------------------
DROP PROCEDURE IF EXISTS `proc_LineNumsRate`;
DELIMITER ;;
CREATE DEFINER=`root`@`127.0.0.1` PROCEDURE `proc_LineNumsRate`(
		_typeName varchar(20), 
		out numsRate decimal(10,3)
)
    READS SQL DATA
begin
		declare totalNum int; -- 定义全部线路数
declare num int;  -- 定义指定类型的线路数
		select count(*) into totalNum from line;
		select count(*) into num from line L, linetype LT where L.lineTypeID=LT.lineTypeID 
and LT.typeName=_typeName;
		-- 生成指定类型的线路数与全部线路数之比，赋给输出参数numsRate
		set numsRate=num*1.0/totalNum;
end
;;
DELIMITER ;

-- ----------------------------
-- Procedure structure for `proc_NumsGivenLineType`
-- ----------------------------
DROP PROCEDURE IF EXISTS `proc_NumsGivenLineType`;
DELIMITER ;;
CREATE DEFINER=`root`@`127.0.0.1` PROCEDURE `proc_NumsGivenLineType`(
		_typeName varchar(20),  
		out count int  -- 输出参数，用于输出指定线路类型的总预订数
)
    READS SQL DATA
begin
		select count(OLD.lineID) into count from ol_detail OLD, line L, lineType LT
		where OLD.lineID=L.lineID and L.lineTypeID=LT.lineTypeID and typeName=_typeName;
end
;;
DELIMITER ;

-- ----------------------------
-- Procedure structure for `proc_PriceModify`
-- ----------------------------
DROP PROCEDURE IF EXISTS `proc_PriceModify`;
DELIMITER ;;
CREATE DEFINER=`root`@`127.0.0.1` PROCEDURE `proc_PriceModify`()
    MODIFIES SQL DATA
begin
		declare _lineID int; 
		declare _days int; -- 线路旅程天数
		declare reduce_money decimal(10,2); -- 减免的住宿费
		declare state varchar(20); -- 错误状态
		declare line_cursor1 cursor for select lineID, days from line where hotel='二星级';
		declare continue handler for 1329 set state='error';
		open line_cursor1;
		traverse_line:while true do
			fetch line_cursor1 into _lineID, _days;			
			if(state='error') then
				leave traverse_line;
			end if;
			set reduce_money=(_days-1)*30;
			update line set price=price-reduce_money where lineID=_lineID;
		end while;
		close line_cursor1;
end
;;
DELIMITER ;

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