Algorithm
Problem Name: Sql -
In this HackerRank Functions in SQL problem solution,
You are given a table, Functions, containing two columns: X and Y.
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.
Sample Input
Sample Output
20 20
20 21
22 23
Code Examples
#1 Code Example with SQL
Code -
SQL
with t1 as
(select f.x, f.y, row_number() over(order by x,y) as row_num
from functions f)
select t1.x, t2.x
from t1
join t1 t2 on t1.x = t2.y and t1.y = t2.x and t1.row_num < t2.row_num
where t1.x <= t2.x
order by t1.x;