Combining two aggregate queries into one - sql

Question

For some context, I am making an image browser which is connected to an SQLite database. Within the browser, similar images are grouped into an event (EventId) and each image (MicrosoftId) is labelled with a few tags (name).
I have these two queries on the same table (TagsMSCV) but pulling out different information. Ultimately I need to combine the information in my browser so if it was possible to combine these two queries (maybe with a JOIN?) it would be a lot faster and convenient for me. Both results of these queries share the EventId column.
1st Query ():
SELECT EventId as 'event', count(*) as 'size',
SUM(case when tag_count = 1 then 1 else 0 end) as '1',
SUM(case when tag_count = 2 then 1 else 0 end) as '2',
SUM(case when tag_count = 3 then 1 else 0 end) as '3'
FROM (SELECT EventId, MicrosoftId,
SUM(case when name in ('indoor', 'cluttered', 'screen') then 1 else 0 end) as tag_count
FROM TagsMSCV GROUP BY EventId, MicrosoftId) TagsMSCV
GROUP BY EventId ORDER BY 3 DESC, 2 DESC, 1 DESC
2nd Query
SELECT EventId,
SUM(CASE WHEN name = 'indoor' THEN 1 ELSE 0 END) as indoor,
SUM(CASE WHEN name = 'cluttered' THEN 1 ELSE 0 END) as cluttered,
SUM(CASE WHEN name = 'screen' THEN 1 ELSE 0 END) as screen
FROM TagsMSCV WHERE name IN ('indoor', 'cluttered', 'screen')
GROUP BY EventId
As you can see in both queries I am feeding in the tags 'necktie' 'man', 'male' and getting different information back.
SQL Fiddle Here: https://www.db-fiddle.com/f/f8WNimjmZAj1XXeCj4PHB8/3

Answer 1

You should do this all in one query:
SELECT EventId as event, count(*) as size,
SUM(case when (indoor + cluttered + screen) = 1 then 1 else 0 end) as tc_1,
SUM(case when (indoor + cluttered + screen) = 2 then 1 else 0 end) as tc_2,
SUM(case when (indoor + cluttered + screen) = 3 then 1 else 0 end) as tc_3,
SUM(indoor) as indoor,
SUM(cluttered) as cluttered,
SUM(screen) as screen
FROM (SELECT EventId, MicrosoftId,
SUM(CASE WHEN name = 'indoor' THEN 1 ELSE 0 END) as indoor,
SUM(CASE WHEN name = 'cluttered' THEN 1 ELSE 0 END) as cluttered,
SUM(CASE WHEN name = 'screen' THEN 1 ELSE 0 END) as screen
FROM TagsMSCV
GROUP BY EventId, MicrosoftId
) TagsMSCV
GROUP BY EventId
ORDER BY 3 DESC, 2 DESC, 1 DESC;
You need two aggregations to get the information about the tag counts. There is no need to add more aggregations and joins to the query.

Answer 2

You could use an Inner join subquery
SELECT TagsMSCV.EventId as 'event', count(*) as 'size',
SUM(case when tag_count = 1 then 1 else 0 end) as '1',
SUM(case when tag_count = 2 then 1 else 0 end) as '2',
SUM(case when tag_count = 3 then 1 else 0 end) as '3',
t.necktie,
t.man,
t.male
FROM (
SELECT EventId, MicrosoftId,
SUM(case when name in ('necktie' 'man', 'male') then 1 else 0 end) as tag_count
FROM TagsMSCV GROUP BY EventId, MicrosoftId
) TagsMSCV
INNER JOIN (
SELECT EventId,
SUM(CASE WHEN name = 'necktie' THEN 1 ELSE 0 END) as necktie,
SUM(CASE WHEN name = 'man' THEN 1 ELSE 0 END) as man,
SUM(CASE WHEN name = 'male' THEN 1 ELSE 0 END) as male
FROM TagsMSCV WHERE name IN ('necktie' 'man', 'male')
GROUP BY EventId
) t on t.EventId = TagsMSCV.EventId
GROUP BY TagsMSCV.EventId
ORDER BY 3 DESC, 2 DESC, 1 DESC