SQL117. 删除记录(三)
描述
现有一张试卷作答记录表exam_record,其中包含多年来的用户作答试卷记录,结构如下表:
Filed | Type | Null | Key | Extra | Default | Comment |
id | int(11) | NO | PRI | auto_increment | (NULL) | 自增ID |
uid | int(11) | NO | | | (NULL) | 用户ID |
exam_id | int(11) | NO | | | (NULL) | 试卷ID |
start_time | datetime | NO | | | (NULL) | 开始时间 |
submit_time | datetime | YES | | | (NULL) | 提交时间 |
score | tinyint(4) | YES | | | (NULL) | 得分 |
示例1
输入:
drop table if EXISTS exam_record; CREATE TABLE IF NOT EXISTS exam_record ( id int PRIMARY KEY AUTO_INCREMENT COMMENT '自增ID', uid int NOT NULL COMMENT '用户ID', exam_id int NOT NULL COMMENT '试卷ID', start_time datetime NOT NULL COMMENT '开始时间', submit_time datetime COMMENT '提交时间', score tinyint COMMENT '得分' )CHARACTER SET utf8 COLLATE utf8_general_ci; TRUNCATE exam_record; INSERT INTO exam_record(uid, exam_id, start_time, submit_time, score) VALUES (1001, 9001, '2020-01-01 22:11:12', '2020-01-01 23:16:12', 50), (1001, 9002, '2020-01-02 09:01:01', '2020-01-02 09:06:00', 58);
输出:
0|None
Mysql 解法, 执行用时: 36ms, 内存消耗: 6204KB, 提交时间: 2021-12-03
TRUNCATE table exam_record;
Mysql 解法, 执行用时: 36ms, 内存消耗: 6244KB, 提交时间: 2022-01-22
truncate exam_record
Mysql 解法, 执行用时: 36ms, 内存消耗: 6268KB, 提交时间: 2021-12-09
TRUNCATE exam_record
Mysql 解法, 执行用时: 36ms, 内存消耗: 6272KB, 提交时间: 2021-12-06
TRUNCATE table exam_record
Mysql 解法, 执行用时: 36ms, 内存消耗: 6284KB, 提交时间: 2022-01-25
truncate exam_record