MySQL: aggregate data from distinct rows into other distinct rows? - mysql

Question

I know the title is an abomination, but I can't think of a succinct way to describe my problem.
I have a table called onsite_notes. onsite_notes's PK is a field called onsite_note_id. I'm trying to get all of the notes' time added up for each customer. Currently, my query is returning double entries for some rows. I'm not sure why, but it's really annoying. What I want to do is count distinct rows that have a specific FK (customer_id). Here's the current query.
SELECT c.searchable_name, co.*, sum(n.time)
as worked_hours_onsite, 'onsite' as type
FROM customers c
LEFT JOIN contracts co on c.customer_id = co.customer_id
LEFT JOIN onsite_tickets t ON t.customer_id = c.customer_id
LEFT JOIN onsite_notes n ON t.onsite_id = n.onsite_id
and (n.date >= 1464760800)
and (n.date < 1467352800)
and (n.isbillable = 1)
WHERE co.contract_type != '' AND
((timestamp(now()) between co.start_date and co.end_date)
OR ((timestamp(now()) <= co.end_date) AND (co.start_date = 0))
OR ((timestamp(now()) >= co.start_date) AND (co.end_date = 0))
OR ((co.start_date = 0) AND (co.end_date=0)))
GROUP BY c.customer_id DESC ) ....
That's the general idea of the thing. It's got a unioned bit, but it's giving me the same headache. Basically, how can I ensure that I'm getting unique rows for each customer? My customer rows are unique, but the aggregated data isn't unique and I want it unique.

Answer 1

If you want a sum you need a proper group by based ond the row you want grouped and if you have selected column you must adeguate the group by to the row you want selected
.. If you need distinct don't use group by
and last group by don't need desc .. desc i for order by so the query should be somethings like this
SELECT c.searchable_name, co.*, sum(n.time)
as worked_hours_onsite, 'onsite' as type
FROM customers c
LEFT JOIN contracts co on c.customer_id = co.customer_id
LEFT JOIN onsite_tickets t ON t.customer_id = c.customer_id
LEFT JOIN onsite_notes n ON t.onsite_id = n.onsite_id
and (n.date >= 1464760800)
and (n.date < 1467352800)
and (n.isbillable = 1)
WHERE co.contract_type != '' AND
((timestamp(now()) between co.start_date and co.end_date)
OR ((timestamp(now()) <= co.end_date) AND (co.start_date = 0))
OR ((timestamp(now()) >= co.start_date) AND (co.end_date = 0))
OR ((co.start_date = 0) AND (co.end_date=0)))
GROUP BY c.searchable_name, co.*