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Given this query:

SELECT DISTINCT a.dogTag, a.dateEdited
FROM dvdpedia a
JOIN dvd_uploads b ON a.dogTag = b.dogTag
JOIN dvd_moderators c ON a.dogTag = c.dogTag
WHERE b.uploader != 9  AND c.moderator != 9
ORDER BY a.dogTag ASC
LIMIT 50;

I only want to select the rows from dvd_moderators that appear only once, that is that have been moderated once only and not more and that don't match the userID given (9 in this example).

dvd_moderators would look something like this:

id    dogTag    moderator
219    2         9
2226   2         7

Of course the moderator ID would change for other entries.

Using a COUNT works mostly except when the userID matches the moderator:

SELECT  a.dogTag, a.dateEdited, COUNT(c.dogTag) AS moderations
FROM dvdpedia a
JOIN dvd_uploads b ON a.dogTag = b.dogTag
JOIN dvd_moderators c ON a.dogTag = c.dogTag
WHERE b.uploader != 9 AND c.moderator != 9
GROUP BY c.dogTag
HAVING moderations = 1  
ORDER BY a.dogTag ASC
LIMIT 50;

Then it reports it as being moderated only once (which is a correct query, it is discarding the row that matches moderator = 9 and hence the count is coming out to 1 instead of 2) but incorrect for the purposes I need.

Basically I want the rows that have been moderated only once and that one of those moderators does not match the userID (9 in the example above).

How could I achieve this?

Thanks.

4

2 に答える 2

3

Thanks to Guido over at Sitepoint, this is the soluton he provided. I am putting it here in the hopes it will help someone else in a similar situation:

SELECT a.dogTag, a.dateEdited
FROM dvdpedia a
JOIN dvd_uploads b ON a.dogTag = b.dogTag
JOIN dvd_moderators c ON a.dogTag = c.dogTag
JOIN
 (SELECT dogTag
  FROM dvd_moderators
  GROUP BY dogTag
  HAVING count(dogTag) = 1
 ) AS d
ON a.dogTag = d.dogTag
WHERE 1=1 
AND   b.uploader != 9 
AND   c.moderator != 9
ORDER BY a.dogTag ASC
LIMIT 50;

And the link to that post if anyone is interested.

于 2012-09-19T14:13:43.037 に答える
0 
SELECT  a.dogTag, a.dateEdited, COUNT(c.dogTag) AS moderations 
FROM dvdpedia a 
JOIN dvd_uploads b ON a.dogTag = b.dogTag AND b.uploader != 9
JOIN dvd_moderators c ON a.dogTag = c.dogTag AND c.moderator != 9
GROUP BY c.dogTag 
HAVING moderations = 1   
ORDER BY a.dogTag ASC 
LIMIT 50;
于 2012-09-19T11:37:22.553 に答える