Formatted question description: https://leetcode.ca/all/619.html
619. Biggest Single Number
my_numbers contains many numbers in column num including duplicated ones.
Can you write a SQL query to find the biggest number, which only appears once.
+---+ |num| +---+ | 8 | | 8 | | 3 | | 3 | | 1 | | 4 | | 5 | | 6 |
For the sample data above, your query should return the following result:
+---+ |num| +---+ | 6 |
If there is no such number, just output null.
select max(num) to select the biggest number. To select the biggest number that only appears once, use
having count(num) = 1 as a condition.
# Write your MySQL query statement below select max(num) as num from (select num from my_numbers group by num having count(num) = 1) as t;