create table user( id int primary key auto_increment, BookName varchar(255) not null, AuthorName varchar(255) not null, Publishing varchar(255) not null, regTime datetime );
时间: 2024-04-11 20:32:35 浏览: 120
您创建的是一个名为"user"的表,包含以下字段:
- id: 整数类型,主键,自增长
- BookName: 字符串类型,长度为255,不能为空
- AuthorName: 字符串类型,长度为255,不能为空
- Publishing: 字符串类型,长度为255,不能为空
- regTime: 日期时间类型,用于记录注册时间
请注意,在SQL语句中,逗号应该是英文半角逗号,并且表名、字段名和数据类型之间要用空格分隔。
相关问题
CREATE TABLE customer ( id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(50) NOT NULL, gender ENUM('男', '女') NOT NULL, phone VARCHAR(20) NOT NULL, address VARCHAR(100) NOT NULL ); CREATE TABLE car_model( id INT PRIMARY KEY AUTO_INCREMENT, brand VARCHAR(50) NOT NULL, model VARCHAR(50) NOT NULL, price DECIMAL(10,2) NOT NULL ); CREATE TABLE car( model_id INT PRIMARY KEY AUTO_INCREMENT, color VARCHAR(50) NOT NULL, description VARCHAR(50) NOT NULL ); CREATE TABLE order1( id INT PRIMARY KEY AUTO_INCREMENT, customer_id INT NOT NULL, car_id INT NOT NULL, order_date DATETIME NOT NULL , price DECIMAL(10,2) NOT NULL, ); CREATE TABLE employee( id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(50) NOT NULL, gender ENUM('男', '女') NOT NULL, phone VARCHAR(20) NOT NULL, address VARCHAR(100) NOT NULL, salary DECIMAL(10,2) NOT NULL给出五个存储函数以及调用语句 );
存储函数1:
DELIMITER //
CREATE FUNCTION get_total_price(order_id INT)
RETURNS DECIMAL(10,2)
BEGIN
DECLARE total_price DECIMAL(10,2);
SELECT SUM(price) INTO total_price FROM order1 WHERE id = order_id;
RETURN total_price;
END//
DELIMITER ;
调用语句:SELECT get_total_price(1);
存储函数2:
DELIMITER //
CREATE FUNCTION get_customer_orders(customer_name VARCHAR(50))
RETURNS INT
BEGIN
DECLARE order_count INT;
SELECT COUNT(*) INTO order_count FROM order1 o JOIN customer c ON o.customer_id = c.id WHERE c.name = customer_name;
RETURN order_count;
END//
DELIMITER ;
调用语句:SELECT get_customer_orders('John Doe');
存储函数3:
DELIMITER //
CREATE FUNCTION get_employee_salary_increase(employee_id INT, percent DECIMAL(10,2))
RETURNS DECIMAL(10,2)
BEGIN
UPDATE employee SET salary = salary * (1 + percent/100) WHERE id = employee_id;
RETURN salary;
END//
DELIMITER ;
调用语句:SELECT get_employee_salary_increase(1, 10);
存储函数4:
DELIMITER //
CREATE FUNCTION get_model_count(brand_name VARCHAR(50))
RETURNS INT
BEGIN
DECLARE model_count INT;
SELECT COUNT(*) INTO model_count FROM car_model WHERE brand = brand_name;
RETURN model_count;
END//
DELIMITER ;
调用语句:SELECT get_model_count('Toyota');
存储函数5:
DELIMITER //
CREATE FUNCTION get_car_info(car_id INT)
RETURNS VARCHAR(100)
BEGIN
DECLARE car_info VARCHAR(100);
SELECT CONCAT(c.color, ' ', cm.brand, ' ', cm.model) INTO car_info FROM car c JOIN car_model cm ON c.model_id = cm.id WHERE c.id = car_id;
RETURN car_info;
END//
DELIMITER ;
调用语句:SELECT get_car_info(1);
//创建表 -- 创建餐厅表 CREATE TABLE restaurant ( id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(50) NOT NULL, address VARCHAR(100) NOT NULL, phone VARCHAR(20) NOT NULL ); -- 创建菜品表 CREATE TABLE menu ( id INT PRIMARY KEY AUTO_INCREMENT, restaurant_id INT, name VARCHAR(50) NOT NULL, description VARCHAR(200), price DECIMAL(8,2) NOT NULL, FOREIGN KEY (restaurant_id) REFERENCES restaurant(id) ); -- 创建用户表 CREATE TABLE user ( id INT PRIMARY KEY AUTO_INCREMENT, username VARCHAR(50) NOT NULL, password VARCHAR(50) NOT NULL, email VARCHAR(50) NOT NULL, phone VARCHAR(20) NOT NULL ); -- 创建订单表 CREATE TABLE orders ( id INT PRIMARY KEY AUTO_INCREMENT, user_id INT, restaurant_id INT, create_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP, FOREIGN KEY (user_id) REFERENCES user(id), FOREIGN KEY (restaurant_id) REFERENCES restaurant(id) ); -- 创建订单明细表 CREATE TABLE order_details ( id INT PRIMARY KEY AUTO_INCREMENT, order_id INT, menu_id INT, quantity INT NOT NULL, FOREIGN KEY (order_id) REFERENCES orders(id), FOREIGN KEY (menu_id) REFERENCES menu(id) ); 数据库创建有上面五张表,定义触发器,当删除菜单,插入菜单,修改菜单时触发,同时对菜单表信息更新
要定义一个触发器,当删除菜单、插入菜单或修改菜单时触发,并同步更新菜单表信息,可以使用以下示例代码:
```sql
-- 创建触发器,当删除菜单时触发
CREATE TRIGGER delete_menu_trigger
AFTER DELETE ON menu
FOR EACH ROW
BEGIN
-- 删除相关的订单明细
DELETE FROM order_details WHERE menu_id = OLD.id;
END;
-- 创建触发器,当插入菜单时触发
CREATE TRIGGER insert_menu_trigger
AFTER INSERT ON menu
FOR EACH ROW
BEGIN
-- 更新菜单数量
UPDATE restaurant SET menu_count = menu_count + 1 WHERE id = NEW.restaurant_id;
END;
-- 创建触发器,当修改菜单时触发
CREATE TRIGGER update_menu_trigger
AFTER UPDATE ON menu
FOR EACH ROW
BEGIN
-- 更新菜单名称和价格
UPDATE order_details SET menu_name = NEW.name, menu_price = NEW.price WHERE menu_id = NEW.id;
END;
```
上述代码中,`delete_menu_trigger` 是删除菜单触发器的名称,`insert_menu_trigger` 是插入菜单触发器的名称,`update_menu_trigger` 是修改菜单触发器的名称。`AFTER DELETE ON menu` 表示在菜单表上进行删除操作时触发对应的触发器,`AFTER INSERT ON menu` 表示在菜单表上进行插入操作时触发对应的触发器,`AFTER UPDATE ON menu` 表示在菜单表上进行修改操作时触发对应的触发器。
在触发器中,我们可以编写相应的操作逻辑来实现同步更新菜单表信息。例如,在 `delete_menu_trigger` 触发器中,我们使用 `DELETE FROM order_details WHERE menu_id = OLD.id;` 语句来删除相关的订单明细;在 `insert_menu_trigger` 触发器中,我们使用 `UPDATE restaurant SET menu_count = menu_count + 1 WHERE id = NEW.restaurant_id;` 语句来更新餐厅表中的菜单数量;在 `update_menu_trigger` 触发器中,我们使用 `UPDATE order_details SET menu_name = NEW.name, menu_price = NEW.price WHERE menu_id = NEW.id;` 语句来更新订单明细表中的菜单名称和价格。
请根据你的数据库结构和具体需求修改触发器中的表名、字段名和操作逻辑。
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