利用MySQL实现一个类似美团外卖的外卖订单的数据库管理系统

利用MySQL实现一个类似美团外卖的外卖订单的数据库管理系统

本文的重点在于MySQL触发器的应用

1、数据库需求分析

​ 1）数据库实体：客户、商家、商品、订单。

​ 2）一个客户对应多个订单。

​ 3）一个商家对应多种商品和多个订单。

​ 4）一个订单对应一种商品。

2、系统功能分析

​ 1）客户注册：客户通过添加必要的信息到数据库来完成注册。

​ 2）客户信息修改：客户根据自己的编号来修改除编号外的其他信息。

​ 3）商家注册：商家通过添加必要的信息到数据库来完成注册。

​ 4）商家信息修改：商家根据自己的编号来修改除编号外的其他信息。

​ 5）商品录入：商家通过添加商品必要的信息到数据库来完成商品录入。

​ 6）商品信息修改：商家根据商品编号来修改商品除编号外的其他信息。

​ 7）客户下单：客户通过添加订单信息到数据库来提交订单。

​ 8）商家接单：商家通过修改订单状态来接受订单。

​ 9）客户确认收货：客户通过修改订单状态来确认收货。

​ 10）取消订单：客户通过修改订单状态来退款，但必须在商家接单之前退款。

​ 11）订单状态：“0”表示已支付，“1”表示已接单，“2”表示已送达，“3”表示已退款。

3、关系模式

​ 1）客户（客户编号，客户姓名，消费金额 ，客户电话，客户地址）

​ 2）商家（商家编号，商户名称，营业额 ，商户电话，商户地址）

​ 3）商品（商品编号，商品名称，商户编号，商品价格，限购数量）

​ 4）订单（订单编号，订购时间，客户编号，商品编号，数量，总额，状态）

​ 注：含下划线字段为主键或外键。

4、创建数据库及表

​ 1）创建数据库

CREATE DATABASE takeout;

​ 2）创建客户表

CREATE TABLE customers(
id int NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(40) NOT NULL ,
consumption DOUBLE(16,2) NOT NULL DEFAULT 0,
phone VARCHAR(16) NOT NULL ,
address VARCHAR(45) NOT NULL
);

​ 3）创建商家表

CREATE TABLE businesses(
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(40) NOT NULL ,
turnover DOUBLE(16,2) NOT NULL DEFAULT 0,
phone VARCHAR(16) NOT NULL ,
address VARCHAR(45) NOT NULL
);

​ 4）创建商品表

CREATE TABLE goods(
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(40) NOT NULL ,
business_id INT NOT NULL ,
price DOUBLE(16,2) NOT NULL ,
limit_num INT ,
FOREIGN KEY (business_id) REFERENCES businesses(id)
);

​ 5）创建订单表

CREATE TABLE orders(
id INT NOT NULL AUTO_INCREMENT,
order_time DATETIME NOT NULL ,
customer_id INT NOT NULL ,
goods_id INT NOT NULL ,
number INT NOT NULL ,
total_cost DOUBLE(16,2) NOT NULL ,
state INT NOT NULL DEFAULT 0 ,
PRIMARY KEY (id),
FOREIGN KEY (customer_id) REFERENCES customers(id),
FOREIGN KEY (goods_id) REFERENCES goods(id)
);

5、创建触发器

​ 1）创建触发器前修改sql语句结束符为

#

DELIMITER #

​ 2）限购以及计算订单总额

  创建之后，在客户订购的商品数量超过限购数量时，自动将订购的数量改为限购数量，然后计算出订单总额。

CREATE TRIGGER limit_buy
BEFORE INSERT
ON orders
FOR EACH ROW
BEGIN
DECLARE p DOUBLE(16,2);  /*商品单价*/
DECLARE lim INT;  /*限购数量*/
SET p=(SELECT price FROM goods WHERE goods.id=NEW.goods_id);
SET lim=(SELECT limit_num FROM goods WHERE goods.id=NEW.goods_id);
if (lim IS NOT NULL AND NEW.number>lim) THEN
SET NEW.number=lim;
END IF ;
SET NEW.total_cost=NEW.number*p;
END #

​ 3）更新客户消费总额

  在客户提交订单之后，自动将消费金额累加到客户总的消费金额里。

CREATE TRIGGER calculate_consumption
AFTER INSERT
ON orders
FOR EACH ROW
BEGIN
UPDATE customers
SET consumption=consumption+NEW.total_cost
WHERE customers.id=NEW.customer_id;
END #

​ 4）更新商家总营业额以及退款

  商家接单后，自动将订单金额累加到商家的营业额里；客户取消订单，自动将客户总消费减去本次订单金额。

CREATE TRIGGER calculate_turnover
BEFORE UPDATE
ON orders
FOR EACH ROW
BEGIN
IF (NEW.state=1 AND OLD.state=0) THEN
UPDATE businesses
SET turnover=turnover+OLD.total_cost
WHERE id=(SELECT business_id FROM goods WHERE goods.id=NEW.goods_id);
ELSEIF (NEW.state=3 AND OLD.state=0) THEN
UPDATE customers
SET consumption=consumption-OLD.total_cost
WHERE id=OLD.customer_id;
ELSEIF (NEW.state<OLD.state) THEN
SET NEW.state=OLD.state;
END IF ;
END #

​ 5）创建完触发器后将sql语句结束符修改回

;

DELIMITER ;

​ 6）查看触发器

SHOW TRIGGERS;

​结果截图（局部）

6、客户注册及信息修改

​ 1）客户注册

INSERT INTO customers(name, phone, address)
VALUES ('李白','18512312300','华东交通大学42公寓');
INSERT INTO customers(name, phone, address)
VALUES ('杜甫','18612312301','华东交通大学43公寓');
INSERT INTO customers(name, phone, address)
VALUES ('马云云','18712312302','华东交通大学37公寓');
INSERT INTO customers(name, phone, address)
VALUES ('马花腾','18712412303','江西理工大学11公寓');
INSERT INTO customers(name, phone, address)
VALUES ('孙悟空','18572352304','江西财经大学32公寓');
INSERT INTO customers(name, phone, address)
VALUES ('唐僧','18632314305','江西财经大学9公寓');
INSERT INTO customers(name, phone, address)
VALUES ('武则天','18712312406','江西财经大学21公寓');
INSERT INTO customers(name, phone, address)
VALUES ('独孤求败','18519312307','江西理工大学13公寓');
INSERT INTO customers(name, phone, address)
VALUES ('展昭','18112332808','江西理工大学25公寓');
INSERT INTO customers(name, phone, address)
VALUES ('赵灵儿','18112812309','华东交通大学8公寓');
INSERT INTO customers(name, phone, address)
VALUES ('东方不败','18152862310','江西财经大学34公寓');
INSERT INTO customers(name, phone, address)
VALUES ('貂蝉','18352388511','江西理工大学24公寓');

​ 结果截图



​ 2）客户信息修改

UPDATE customers SET phone='15789654314' WHERE id=2;
UPDATE customers SET address='华东交通大学创新大楼' WHERE id=3;
UPDATE customers SET address='江西财经大学大学生活动中心' WHERE id=7;

​ 结果截图

7、商家注册及信息修改

​ 1）商家注册

INSERT INTO businesses(name, phone, address)
VALUES ('回家吃饭','400123100','南昌市双港东大街333号');
INSERT INTO businesses(name, phone, address)
VALUES ('佳佳饺子馆','400123101','南昌市双港东大街531号');
INSERT INTO businesses(name, phone, address)
VALUES ('港式脆排饭','400123102','南昌市邹家自然村交通学院旁');
INSERT INTO businesses(name, phone, address)
VALUES ('膳当家','400123103','南昌市华东交通大学');
INSERT INTO businesses(name, phone, address)
VALUES ('沙县小吃','400123104','南昌市双港东大街立通大厦旁');

​ 结果截图



​ 2）商家信息修改

UPDATE businesses SET phone='18788484186' WHERE id=2;
UPDATE businesses SET address='南昌市江西理工大学对面' WHERE id=3;
UPDATE businesses SET address='南昌云鹏大酒店旁' WHERE id=5;

​ 结果截图

8、商品录入及商品信息修改

​ 1）商品录入

INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('重庆鸡公煲',1,13.9,1);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('麻辣香锅',1,12.5,5);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('土豆烧牛腩',1,14.9,NULL);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('韭菜猪肉馅',2,14.9,3);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('香菇猪肉馅',2,14.9,3);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('玉米猪肉馅',2,15.9,3);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('黑椒脆排饭',3,9.9,NULL);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('孜然脆排饭',3,9.5,NULL);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('叉烧脆排饭',3,11.8,2);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('腐竹黄焖鸡',4,10.8,3);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('黄焖鸡小份微辣',4,13,5);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('黄焖鸡小份中辣',4,14,5);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('鲜肉蒸饺',5,4,6);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('香拌混沌',5,5,3);
INSERT INTO goods(name, business_id, price, limit_num)
VALUES ('蛋炒南昌米粉',5,7,NULL);

​ 结果截图



​ 2）商品信息修改

UPDATE goods SET name='韭菜牛肉馅' WHERE id=4;
UPDATE goods SET limit_num=5 WHERE id=6;
UPDATE goods SET price=4.5 WHERE id=13;

​ 结果截图

9、外卖订购流程

​ 1）客户提交订单

INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2017-12-8 12:14:35',2,3,2);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2017-12-8 11:45:12',4,5,5);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2017-12-9 18:14:35',5,13,7);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2017-12-9 19:44:35',9,12,1);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2017-12-10 11:55:34',7,14,6);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-3 12:04:42',1,7,9);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-5 13:11:56',3,4,1);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-11 18:09:27',9,8,1);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-12 13:11:56',11,8,4);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-15 19:28:49',5,14,3);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-16 13:08:40',7,1,2);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-17 17:30:29',9,4,5);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-19 12:00:26',12,9,2);
INSERT orders(order_time, customer_id, goods_id, number)
VALUES ('2018-1-21 17:34:56',4,14,4);

​结果截图

 可以看到订单表的订单金额已自动计算好了



 客户的消费金额也已经自动更新



​ 2）客户取消订单

UPDATE orders SET state=3 WHERE id=4;
UPDATE orders SET state=3 WHERE id=10;

​ 结果截图





​ 3）商家接单

UPDATE orders SET state=1 WHERE id=1;
UPDATE orders SET state=1 WHERE id=2;
UPDATE orders SET state=1 WHERE id=3;
UPDATE orders SET state=1 WHERE id=5;
UPDATE orders SET state=1 WHERE id=6;
UPDATE orders SET state=1 WHERE id=7;
UPDATE orders SET state=1 WHERE id=8;
UPDATE orders SET state=1 WHERE id=9;
UPDATE orders SET state=1 WHERE id=11;
UPDATE orders SET state=1 WHERE id=12;
UPDATE orders SET state=1 WHERE id=13;
UPDATE orders SET state=1 WHERE id=14;

​ 结果截图



 商家的营业额已自动更新



​ 4）客户确认收货

UPDATE orders SET state=2 WHERE id=1;
UPDATE orders SET state=2 WHERE id=2;
UPDATE orders SET state=2 WHERE id=3;
UPDATE orders SET state=2 WHERE id=5;
UPDATE orders SET state=2 WHERE id=6;
UPDATE orders SET state=2 WHERE id=7;
UPDATE orders SET state=2 WHERE id=8;
UPDATE orders SET state=2 WHERE id=9;
UPDATE orders SET state=2 WHERE id=11;
UPDATE orders SET state=2 WHERE id=12;
UPDATE orders SET state=2 WHERE id=13;
UPDATE orders SET state=2 WHERE id=14;

​ 结果截图

10、创建订单详情视图

CREATE VIEW order_details AS
SELECT orders.id AS 订单编号, businesses.name AS 商家名称, goods.name AS 商品名称,
number AS 数量, total_cost AS 总额, state AS 订单状态, customers.name AS 客户姓名,
customers.phone AS 电话, customers.address AS 地址, order_time AS 时间
FROM ((businesses INNER JOIN goods ON businesses.id = goods.business_id)
INNER JOIN orders ON goods.id = orders.goods_id)
INNER JOIN customers ON orders.customer_id=customers.id;

​ 查看视图

SELECT * FROM order_details;

11、客户总消费及商家总营业额对比

SELECT sum(consumption) AS 总消费
FROM customers;
SELECT sum(turnover) AS 总营业额
FROM businesses;

​ 得出的结果应该是一样的，结果截图

12、查看2018年1月份商家的营业额排行榜

SELECT businesses.id AS 商家编号, businesses.name AS 商家名称,
sum(total_cost) AS 2018年1月营业额
FROM (orders INNER JOIN goods ON orders.goods_id = goods.id)
INNER JOIN businesses ON business_id = businesses.id
WHERE state IN (1,2) AND date(order_time) BETWEEN '2018-01-01' AND '2018-01-31'
GROUP BY businesses.id
ORDER BY 2018年1月营业额 DESC ;

​ 结果截图