`id` int(11) NOT NULL AUTO_INCREMENT, `kefang_id` int(11) DEFAULT NULL, `shijian` varchar(50) DEFAULT NULL, `kehuname` varchar(50) DEFAULT NULL, `kehutel` varchar(50) DEFAULT NULL, `tianshu` varchar(50) DEFAULT NULL, `xiaofeijine` int(11) DEFAULT NULL, `del` varchar(50) DEFAULT NULL,这个SQ语句是什么意思

这个SQL语句是一个创建表的语句，其中定义了一个名为`id`的整型字段，一个名为`kefang_id`的整型字段，一个名为`shijian`的字符串型字段，一个名为`kehuname`的字符串型字段，一个名为`kehutel`的字符串型字段，一个名为`tianshu`的字符串型字段，一个名为`xiaofeijine`的整型字段，一个名为`del`的字符串型字段。该表的自增长ID为`id`，`kefang_id`，`shijian`，`kehuname`，`kehutel`，`tianshu`，`xiaofeijine`和`del`分别为可选的默认值。

相关问题

CREATE TABLE `admin` ( `admin_id` int(11) NOT NULL AUTO_INCREMENT, `admin_name` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL, `admin_number` int(11) NOT NULL AUTO_INCREMENT, PRIMARY KEY (`admin_id`) USING BTREE, )ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC;这段代码有什么错误，怎样改

这段代码有一个错误，即 `admin_number` 列的定义不正确。`AUTO_INCREMENT` 属性只能应用于主键列，而 `admin_number` 列不是主键列，因此不能使用 `AUTO_INCREMENT` 属性。此外，`admin_number` 列的数据类型也没有指定，应该为整数类型。

应该将代码修改为：

CREATE TABLE `admin` (
   `admin_id` int(11) NOT NULL AUTO_INCREMENT,
   `admin_name` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
   `admin_number` int(11) NOT NULL,
   PRIMARY KEY (`admin_id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC;

修改后的代码中，`admin_number` 列的定义变为了 `int(11) NOT NULL`，去掉了 `AUTO_INCREMENT` 属性，同时在主键定义中指定了使用 BTREE 索引算法。

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);