hackerrank sql题每日打卡刷题

我打算每天刷至少五道hackerrank sql题的答案，尽量在几周内将题刷完，我会将我认为比较难的和值得讨论的题目贴上，希望大家可以一起讨论，有想组队刷题的小伙伴欢迎私信，互相监督。

Two pairs *(X1, Y1)* and *(X2, Y2)* are said to be *symmetric* *pairs* if *X1 = Y2* and *X2 = Y1*. Write a query to output all such *symmetric* *pairs* in ascending order by the value of *X*. List the rows such that *X1 ≤ Y1*.

--- inner join
select f1.x, f1.y from functions f1 inner join functions f2 on f1.x= f2.y and f1.y=f2.x
group by f1.x, f1.y
--- their are two pairs
having count(f1.x)>1 or f1.x<f1.y
order by f1.x;

赞！！请问每天5题要刷几个小时呢？

Write a query identifying the type of each record in the TRIANGLES table using its three side lengths. Output one of the following statements for each record in the table:

Equilateral: It's a triangle with  sides of equal length.
Isosceles: It's a triangle with  sides of equal length.
Scalene: It's a triangle with  sides of differing lengths.
Not A Triangle: The given values of A, B, and C don't form a triangle.
Input Format

select case when A + B > C and A+C > B and B+C>A then
    case when A = B and B = C then 'Equilateral'
    when A = B or A=C or B=C then 'Isosceles'
    else 'Scalene' end
else 'Not A Triangle' end
from triangles;

睡不着的喵 发表于 2020-11-16 00:56
赞！！请问每天5题要刷几个小时呢？

中等难度题大概1hour以内

shanghaigou 发表于 2020-11-18 19:03:56
中等难度题大概1hour以内

我还在刷EASY的 也是5题差不多1小时。。。 听有人说EASY一题2-3分钟好羡慕 我读题都能读2分钟 怀疑自己是不是智商不够。。