# Weather Observation Station 12

Query the list of _CITY_ names from **STATION** that _do not start_ with vowels and _do not end_ with vowels. Your result cannot contain duplicates.

{% embed url="https://www.hackerrank.com/challenges/weather-observation-station-12/problem" %}



Sol:

select distinct city from station where not city regexp '^\[aeoiu]' and not city regexp '\[aeiou]$'



Explanation:

This query retrieves distinct city names from the STATION table where the city name does not start with a vowel ('a', 'e', 'o', 'i', or 'u') and does not end with a vowel.

* NOT CITY REGEXP '^\[aeoiu]': This condition in the WHERE clause checks if the CITY column does not match the pattern defined by the regular expression.
  * ^\[aeoiu]: This part of the regular expression matches city names that start with any of the vowels 'a', 'e', 'o', 'i', or 'u'.
  * NOT: This negates the condition, selecting city names that do not match the defined pattern at the beginning of the city name.
* NOT CITY REGEXP '\[aeiou]$': This condition in the WHERE clause checks if the CITY column does not match the pattern defined by the regular expression.
  * \[aeiou]$: This part of the regular expression matches city names that end with any of the vowels 'a', 'e', 'o', 'i', or 'u'.
  * NOT: This negates the condition, selecting city names that do not match the defined pattern at the end of the city name.

So, the query selects cities where the city name neither starts nor ends with a vowel.
