LeetCode MySQL刷题——day2

目录

​​一、上升的温度​​

​​1、题目描述​​

​​2、题解​​

​​ 3、源码​​

​​二、大的国家​​

​​1、题目描述​​

​​2、题解​​

​​ 3、源码​​

​​ 三、超过五名学生的课​​

​​1、题目描述​​

​​2、题解 ​​

​​3、源码​​

​​ 四、有趣的电影​​

​​1、题目描述​​

​​2、题解​​

​​3、源码​​

​​ 五、变更性别​​

​​1、题目描述​​

​​ 2、题解​​

​​3、源码​​

一、上升的温度

1、题目描述

2、题解

 3、源码

# Write your MySQL query statement below
select 
    e1.id
from Weather as e1 inner join Weather as e2 on 
    DATEDIFF(e1.recordDate,e2.recordDate) = 1 and e1.Temperature > e2.Temperature;

二、大的国家

1、题目描述

2、题解

 3、源码

# Write your MySQL query statement below
select 
    name,population,area
from World 
    where area >= 3000000 or population >= 25000000;

 三、超过五名学生的课

1、题目描述

2、题解 

3、源码

# Write your MySQL query statement below
select 
    class 
from 
    courses 
GROUP BY class
HAVING COUNT(student) >=5;


# SELECT
#     class
# FROM
#     (SELECT
#         class, COUNT(DISTINCT student) AS num
#     FROM
#         courses
#     GROUP BY class) AS temp_table
# WHERE
#     num >= 5
# ;

 四、有趣的电影

1、题目描述

2、题解

3、源码

select 
    id,movie,description,rating
from 
    cinema
where mod(id,2) = 1 and description != 'boring'
order by rating desc;

 五、变更性别

1、题目描述

 2、题解

3、源码

# Write your MySQL query statement below
update Salary
SET
    sex = CASE sex
        WHEN 'm' THEN 'f'
        ELSE 'm'
    END;