I've got two tables with the following structure:
Question table
id int,
question text,
answer text,
level int
Progress table
qid int,
attempts int,
completed boolean (qid means question id)
Now my questions is how to construct a query that selects the max level where the count of correct questions is greater than let's say 30.
I created this query, but it doesn't work and I don't know why.
SELECT MAX(Questions.level)
FROM Questions, Progress
WHERE Questions.id = Progress.qid AND Progress.completed = 1
GROUP BY Questions.id, Questions.level
Having COUNT(*) >= 30
I would like to have it in one query as I suspect this is possible and probably the most 'optimized' way to query for it. Thanks for the help!
This sort of construct will work. You can figure out the details.
select max(something) maxvalue
from SomeTables
join (select id, count(*) records
from ATable
group by id) temp on ATable.id = temp.id
where records >= 30
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