HackerRank SQL

The PADS

Generate the following two result sets:

1. Query an alphabetically ordered list of all names in OCCUPATIONS, immediately followed by the first letter of each profession as a parenthetical (i.e.: enclosed in parentheses). For example: AnActorName(A), ADoctorName(D), AProfessorName(P), and ASingerName(S).
2. Query the number of ocurrences of each occupation in OCCUPATIONS. Sort the occurrences in ascending order, and output them in the following format:

There are a total of [occupation_count] [occupation]s.

where [occupation_count] is the number of occurrences of an occupation in OCCUPATIONS and [occupation] is the lowercase occupation name. If more than one Occupation has the same [occupation_count], they should be ordered alphabetically.

Note: There will be at least two entries in the table for each type of occupation.

Input Format

The OCCUPATIONS table is described as follows:

Occupation will only contain one of the following values: Doctor, Professor, Singer or Actor.

Sample Input

An OCCUPATIONS table that contains the following records:

Sample Output

Ashely(P)
Christeen(P)
Jane(A)
Jenny(D)
Julia(A)
Ketty(P)
Maria(A)
Meera(S)
Priya(S)
Samantha(D)
There are a total of 2 doctors.
There are a total of 2 singers.
There are a total of 3 actors.
There are a total of 3 professors.

Solution(MySQL):

select concat(name, '(', substring(occupation, 1, 1), ')') as name
from occupations
order by name
select concat('There are a total of', ' ', count(occupation), ' ', 
lower(occupation), 's.') as profession
from occupations
group by occupation
order by profession
;

Solution(MS SQL):

with cte as
(
  select rank() over (partition by occupation order by name) as rnk,
  case when occupation = 'Doctor' then name else null end as Doctor,
  case when occupation = 'Professor' then name else null end as Professor,
  case when occupation = 'Singer' then name else null end as Singer,
  case when occupation = 'Actor' then name else null end as Actor
  from occupations
)
select min(Doctor), min(Professor), min(Singer), min(Actor)
from cte
group by rnk
;

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