Technically, your query might work like this (not entirely sure about the objective of this query):
SELECT 9 AS keyword_id, count(DISTINCT m.id) AS total, t.parent_id AS tag_id
FROM (
SELECT unnest(m.taglist) AS tag_id
FROM mentions m
WHERE m.search_id = 3
AND 9 = ANY (m.taglist)
) m
JOIN tags t USING (tag_id) -- assumes tag.tag_id!
GROUP BY t.parent_id;
However, it seems to me you are going in the wrong direction here. Normally one would remove the redundant array taglist
and keep the normalized database schema. Then your original query should serve well, only shortened the syntax with aliases:
SELECT 9 AS keyword_id, count(DISTINCT m.id) AS total, t.parent_id AS tag_id
FROM mentions m
JOIN taggings mt ON mt.mention_id = m.id
JOIN tags t ON t.id = mt.tag_id
WHERE 9 = ANY (m.taglist)
AND m.search_id = 3
GROUP BY t.parent_id;
Unravel the mystery
<rant>
The root cause for your "different results" is the unfortunate naming convention that some intellectually challenged ORMs impose on people.
I am speaking of
as column name. Never use this anti-pattern in a database with more than one table. Right, that means basically any database. As soon as you join a bunch of tables (that's what you do in a database) you end up with a bunch of columns named idid
. Utterly pointless.
The ID column of a table named tag
should be tag_id
(unless there is another descriptive name). Never id
.
</rant>
Your query inadvertently counts tags
instead of mentions
:
SELECT 25 AS keyword_id, count(m.id) AS total, t.parent_id AS tag_id
FROM (
SELECT unnest(m.taglist) AS id
FROM mentions m
WHERE m.search_id = 4
AND 25 = ANY (m.taglist)
) m
JOIN tags t USING (id)
GROUP BY t.parent_id;
It should work this way:
SELECT 25 AS keyword_id, count(DISTINCT m.id) AS total, t.parent_id
FROM (
SELECT m.id, unnest(m.taglist) AS tag_id
FROM mentions m
WHERE m.search_id = 4
AND 25 = ANY (m.taglist)
) m
JOIN tags t ON t.id = m.tag_id
GROUP BY t.parent_id;
I also added back the DISTINCT
to your count()
that got lost along the way in your query.