SQL - UNION does not order second SELECT - mysql

Question

I`m trying to solve this challenge:
https://www.hackerrank.com/challenges/the-pads
My solution is this in MySQL:
(SELECT CONCAT(Name,'(',SUBSTR(Occupation,1,1),')') FROM Occupations ORDER BY Name)
UNION
(SELECT CONCAT('There are total ', COUNT(Occupation), ' ',LOWER(Occupation),'s.') AS total FROM Occupations
GROUP BY Occupation
ORDER BY total);
However it fails to ORDER BY total.
Ashley(P)
Samantha(A)
Julia(D)
Britney(P)
Maria(P)
Meera(P)
Priya(D)
Priyanka(P)
Jennifer(A)
Ketty(A)
Belvet(P)
Naomi(P)
Jane(S)
Jenny(S)
Kristeen(S)
Christeen(S)
Eve(A)
Aamina(D)
There are total 4 actors.
There are total 3 doctors.
There are total 7 professors.
There are total 4 singers.
If I only run
SELECT CONCAT('There are total ', COUNT(Occupation), ' ',LOWER(Occupation),'s.') AS total FROM Occupations
GROUP BY Occupation
ORDER BY total
it does order:
There are total 3 doctors.
There are total 4 actors.
There are total 4 singers.
There are total 7 professors.

Answer 1

The result gets ordered by the final ORDER BY clause. This is ORDER BY total, i.e. by the first column. (You only give this name in the second part of UNION, which would probably not work in another DBMS. You should name the columns you select in a UNION query in the first part.)
You want to get names first, then the aggregates. Then you want names alphabetically, aggregates by count (i.e. not alphabetically, not 1 -> 10 -> 11 -> 2 -> 20 ..., but 1 -> 2 -> 10 -> 11 -> 20 ...) then by job name. You can create sortkeys for this task. I assume you really want UNION ALL, not UNION. If I am wrong, change it :-)
SELECT txt
FROM
(
SELECT
CONCAT(Name, '(', SUBSTR(Occupation, 1, 1), ')') as txt,
1 as sortkey1,
CONCAT(Name, '(', SUBSTR(Occupation, 1, 1), ')') as sortkey2
FROM Occupations
UNION ALL
SELECT
CONCAT('There are total ', COUNT(Occupation), ' ', LOWER(Occupation), 's.') AS txt,
2 + COUNT(Occupation) as sortkey1,
LOWER(Occupation) as sortkey2
FROM Occupations
GROUP BY Occupation
) data
ORDER BY sortkey1, sortkey2;

Answer 2

That is correct. The ordering of the result set is based only on the outermost order by. This is true for union as for other operations.
(SELECT CONCAT(Name,'(', SUBSTR(Occupation,1,1),')') AS total
FROM Occupations
ORDER BY Name
)
UNION ALL
(SELECT CONCAT('There are total ', COUNT(Occupation), ' ', LOWER(Occupation), 's.') AS total
FROM Occupations
GROUP BY Occupation
)
ORDER BY (CASE WHEN total LIKE 'There are total%' THEN 1 ELSE 0 END),
Total;
This assumes that Name never starts with 'There are total', which seems likely.

Answer 3

#gordon answer is fine
But for a more generic case you have to create a "dummy" field to separate each group.
(SELECT CONCAT(Name,'(', SUBSTR(Occupation,1,1),')') as Name,
0 as dummy
FROM Occupations
)
UNION ALL
(SELECT CONCAT('There are total ', COUNT(Occupation), ' ', LOWER(Occupation), 's.') AS Name,
1 as dummy
FROM Occupations
GROUP BY Occupation
)
ORDER BY dummy, name

Answer 4

Based on the answers and my best understanding I came with this solution that works for this case:
(SELECT CONCAT(Name,'(',SUBSTR(Occupation,1,1),')') as total FROM Occupations ORDER BY Name)
UNION ALL
(SELECT CONCAT('There are total ', COUNT(Occupation), ' ',LOWER(Occupation),'s.') AS total FROM Occupations
GROUP BY Occupation)
ORDER BY total;

Answer 5

This worked for me.
you can give two different select queries whith out UNION/ UNION ALL.
SELECT Concat(NAME, '(', Substr(occupation, 1, 1), ')') AS Result
FROM occupations
ORDER BY NAME;
SELECT Concat('There are a total of ', Count(*), ' ', Lower(occupation), 's.')
FROM occupations
GROUP BY occupation
ORDER BY Count(*), occupation;