SQL11. 高级操作符练习(1)
描述
id | device_id | gender | age | university | gpa |
1 | 2138 | male | 21 | 北京大学 | 3.4 |
2 | 3214 | male | | 复旦大学 | 4.0 |
3 | 6543 | female | 20 | 北京大学 | 3.2 |
4 | 2315 | female | 23 | 浙江大学 | 3.6 |
5 | 5432 | male | 25 | 山东大学 | 3.8 |
device_id | gender | age | university | gpa |
3214 | male | | 复旦大学 | 4.0 |
5432 | male | 25 | 山东大学 | 3.8 |
示例1
输入:
drop table if exists user_profile; CREATE TABLE `user_profile` ( `id` int NOT NULL, `device_id` int NOT NULL, `gender` varchar(14) NOT NULL, `age` int , `university` varchar(32) NOT NULL, `province` varchar(32) NOT NULL, `gpa` float); INSERT INTO user_profile VALUES(1,2138,'male',21,'北京大学','BeiJing',3.4); INSERT INTO user_profile VALUES(2,3214,'male',null,'复旦大学','Shanghai',4.0); INSERT INTO user_profile VALUES(3,6543,'female',20,'北京大学','BeiJing',3.2); INSERT INTO user_profile VALUES(4,2315,'female',23,'浙江大学','ZheJiang',3.6); INSERT INTO user_profile VALUES(5,5432,'male',25,'山东大学','Shandong',3.8);
输出:
3214|male|None|复旦大学|4.0 5432|male|25|山东大学|3.8
Mysql 解法, 执行用时: 36ms, 内存消耗: 6396KB, 提交时间: 2022-01-01
select device_id ,gender,age,university,gpa from user_profile where gpa>3.5 and gender = 'male'
Mysql 解法, 执行用时: 36ms, 内存消耗: 6400KB, 提交时间: 2022-01-22
select device_id,gender,age,university,gpa from user_profile where gender = 'male' and gpa > 3.5
Mysql 解法, 执行用时: 36ms, 内存消耗: 6412KB, 提交时间: 2022-01-25
select device_id,gender,age,university,gpa from user_profile where gpa>3.5 and gender="male";
Mysql 解法, 执行用时: 36ms, 内存消耗: 6412KB, 提交时间: 2021-12-31
select device_id,gender,age,university,gpa from user_profile where gender="male"and gpa>3.5
Mysql 解法, 执行用时: 36ms, 内存消耗: 6416KB, 提交时间: 2021-12-18
select device_id,gender,age,university,gpa from user_profile where gender='male' and gpa>'3.5'