2022-12-01：从不订购的客户。找出所有从不订购任何东西的客户，以下数据的答案输出是Henry和Max，sql语句如何写？ DROP TABLE IF EXISTS `customers`； C

Posted 2022-12-15 福大大架构师每日一题

2022-12-01：从不订购的客户。找出所有从不订购任何东西的客户，以下数据的答案输出是Henry和Max，sql语句如何写？

DROP TABLE IF EXISTS `customers`;
CREATE TABLE `customers` (
  `id` int(11) NOT NULL,
  `name` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

INSERT INTO `customers` VALUES ('1', 'Joe');
INSERT INTO `customers` VALUES ('2', 'Henry');
INSERT INTO `customers` VALUES ('3', 'Sam');
INSERT INTO `customers` VALUES ('4', 'Max');

DROP TABLE IF EXISTS `orders`;
CREATE TABLE `orders` (
  `id` int(11) NOT NULL,
  `customer_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

INSERT INTO `orders` VALUES ('1', '3');
INSERT INTO `orders` VALUES ('2', '1');

答案2022-12-01：

sql语句如下：

select customers.name 
from customers
where customers.id not in
(
    select customer_id from orders
);

运行结果如下：