Count with conditions in different tables - mysql

Question

I have 4 tables (songs, albums and two relation tables).
I have this 2 queries that I need to merge:
-QUERY 1)
SELECT l.name_language, count(s.id_song)
FROM language as l
LEFT JOIN song_has_languages as s ON l.id_language = s.id_language
GROUP BY l.id_language
HAVING COUNT(s.id_song) > 0
ORDER BY name_language ASC
The output:
name_language | songs
English | 5
Spanish | 1
-QUERY 2)
SELECT l.name_language, count(a.id_album)
FROM language as l
LEFT JOIN album_has_languages as a ON l.id_language = a.id_language
GROUP BY l.id_language
HAVING COUNT(a.album)> 0
ORDER BY name_language ASC
The output:
name_language | albums
English | 5
French | 2
My goal is this output:
name_language | total |
English | 10 |
Spanish | 1 |
French | 2 |
I want to print only the languages with a song or an album.

Answer 1

You can do what you want with union all and aggregation:
select l.name_language, sum(num_songs + num_albums) as total
from language l left join
((select shl.id_language, count(*) as num_songs, 0 as num_albums
from song_has_languages shl
group by shl.id_language
) union all
(select ahl.id_language, 0 as num_songs, count(*) as num_albums
from album_has_languages ahl
group by ahl.id_language
)
) sa
on sa.id_language = l.id_language
group by l.id_language, l.name_language;
You could also express this with LEFT JOINs:
select l.name_language,
( coalesce(num_songs, 0) + coalesce(num_albums, 0) ) as total
from language l left join
(select shl.id_language, count(*) as num_songs
from song_has_languages shl
group by shl.id_language
) shl
on shl.id_language = l.id_language left join
(select ahl. id_language, count(*) as num_albums
from album_has_languages ahl
group by ahl.id_language
) ahl
on ahl.id_language = l.id_language;