Weather Observation Station 11

Query the list of CITY names from STATION that either do not start with vowels or do not end with vowels. Your result cannot contain duplicates.

Weather Observation Station 11 | HackerRankHackerRank

Sol:

select distinct city from station where not city regexp '^[aeoiu].*[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].*[aeiou]$': 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'.

  • .*: This part of the regular expression matches any sequence of characters (zero or more) between the first and last character of the city name.

  • [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.

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