CODEWITHSUNDEEP
sqlruby-on-rails-3joinmodelgroup-by
user1946705
user1946705

Reputation: 2888

Rails 3 - problem with a sql query

I have following sql query in Rails 3 syntax:

    variab = Model.joins(:photo).where('photos.user_id = ?', user).group('model.photo_id').count

In the Models table I have these data:

+----+----------+----------+---------------------+----------+
| id | photo_id |  created_at          | updated_at         |
+----+----------+----------+---------------------+----------+
| 31 |      210 | 2011-09-16 14:38:22 | 2011-09-16 14:38:22 |
| 32 |      210 | 2011-09-16 14:38:22 | 2011-09-16 14:38:22 |
| 33 |      211 | 2011-09-16 15:03:26 | 2011-09-16 15:03:26 |
+----+----------+----------+---------------------+----------+

And I try to get the value 2 - I need to get count of unique photo_id data. But if I will use the sql query above, so the output is ** 21022111** - I don't understand, what this number mean... I would assume the output should be 2, but I don't understand, why not...

If anyone could help me with this problem, I would be really glad... Thank you so much

Upvotes: 0

Views: 98

Answers (1)

Steve
Steve

Reputation: 15736

Active Record is returning the photo_id/count pairs, i.e. photo_id 210 count 2, photo_id 211 count 1.

If you want to count the number of distinct photos for a given use then try:

Model.select(:photo_id).where(:user_id => user.id).count(:distinct => true)

Upvotes: 2

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