SQL61. 检索并列出已订购产品的清单
描述
| prod_id |
| a1 |
| a2 |
| a3 |
| a4 |
| a5 |
| a6 |
| a7 |
示例1
输入:
DROP TABLE IF EXISTS `OrderItems`;
CREATE TABLE IF NOT EXISTS `OrderItems`(
prod_id VARCHAR(255) NOT NULL COMMENT '商品id'
);
INSERT `OrderItems` VALUES ('a1'),('a2'),('a3'),('a4'),('a5'),('a6'),('a6')
输出:
a1 a2 a3 a4 a5 a6
Mysql 解法, 执行用时: 38ms, 内存消耗: 6500KB, 提交时间: 2022-03-07
select distinct prod_id from OrderItems where prod_id is not null;
Mysql 解法, 执行用时: 39ms, 内存消耗: 6440KB, 提交时间: 2022-03-03
SELECT prod_id FROM OrderItems group by prod_id
Mysql 解法, 执行用时: 39ms, 内存消耗: 6628KB, 提交时间: 2022-03-03
select Distinct prod_id from OrderItems
Mysql 解法, 执行用时: 39ms, 内存消耗: 6828KB, 提交时间: 2022-03-02
select distinct prod_id from OrderItems
Mysql 解法, 执行用时: 40ms, 内存消耗: 6420KB, 提交时间: 2022-03-02
select distinct prod_id from OrderItems; # where prod_id is not null;