MySQL Join for newsletters - php

Question

I have a problem with mysql query. I am sending newsletters.
My mysql schema looks like to follwing http://sqlfiddle.com/#!2/178b7/18
How am I suppose to get from the database the COUNT of the mails that will be send.
For every List_ID in LISTS TAKE every base_id from lists_mailbases, and then count all of the base_id that are in email_database.
For example in my schema list1 should have 4 recipients, list 2 should have 2 recipients.
I wrote something like this:
SELECT l.id, COUNT(*) FROM lists l
JOIN lists_mailbases lm ON l.id = lm.list_id
JOIN email_database ed ON ed.base_id = lm.base_id
GROUP BY l.id;
but as a result, I have almost twice more results i should have. (on sqlfiddle it is ok but in my main database where i have a lot of records it gives me wrong data)

Answer 1

As you said, you are getting twice as much as you expect, it looks like one of the joins produces more than one record for the join. Diagnose that out.
SELECT ID, COUNT(*)
FROM
(
SELECT l.id, ED.BASE_ID FROM lists l
JOIN lists_mailbases lm ON l.id = lm.list_id
JOIN email_database ed ON ed.base_id = lm.base_id
GROUP BY l.id, ED.BASE_ID
) A;

Answer 2

nice question with SQLFiddle!
just add ed.base_id to your GROUP BY
SELECT l.id,ed.base_id, COUNT(*) , GROUP_CONCAT(ed.email)
FROM lists l JOIN lists_mailbases lm ON l.id = lm.list_id
JOIN email_database ed ON ed.base_id = lm.base_id
GROUP BY l.id,ed.base_id;
your lists_mailbases has repeated data by the way, it has 2 rows with the same base_id.
if your data is correct and you want to count DISTINCT base_id, just do COUNT(DISTINCT base_id)
like below
SELECT l.id, COUNT(DISTINCT ed.base_id) , GROUP_CONCAT(ed.email)
FROM lists l JOIN lists_mailbases lm ON l.id = lm.list_id
JOIN email_database ed ON ed.base_id = lm.base_id
GROUP BY l.id;