Core Server
  1. Core Server
  2. SERVER-2130

Ability to use Limit() with Distinct()

    Details

    • Type: New Feature New Feature
    • Status: Open Open
    • Priority: Major - P3 Major - P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: Planning Bucket B
    • Component/s: Querying
    • Labels:
    • Environment:
      all
    • Backport:
      No
    • # Replies:
      5
    • Last comment by Customer:
      true

      Description

      Ability to use Limit() with Distinct()... or any of the cursor methods for the matter (sort, count, skip, etc. although limit has the biggest impact).

      Apparently there is no simple way to currently perform the following SQL query:

      SELECT DISTINCT(myField) FROM myTable WHERE x = y LIMIT(20)

      The current Distinct() implementation only allows for bringing back ALL distinct values in the collection or matching a query, but there is no way to limit these results. This would be very convenient and there are many use cases.

        Activity

        Hide
        Gerhard Balthasar
        added a comment -

        Using distinct with sort would be my biggest hope for 1.9.0 apart from limit.

        Show
        Gerhard Balthasar
        added a comment - Using distinct with sort would be my biggest hope for 1.9.0 apart from limit.
        Hide
        Dominik Gehl
        added a comment -

        Sort() with Distinct() could also be very useful, for example in the following case:

        Email messages and attachments (attachments saved in an array inside the email message document).
        Getting the distinct list of attachment names ordered by message date would ask for the distinct on 'attachment name', but with a sort on 'message date'.

        Show
        Dominik Gehl
        added a comment - Sort() with Distinct() could also be very useful, for example in the following case: Email messages and attachments (attachments saved in an array inside the email message document). Getting the distinct list of attachment names ordered by message date would ask for the distinct on 'attachment name', but with a sort on 'message date'.
        Hide
        Johan Gustafsson
        added a comment -

        Is this feature resolved yet? If not, is it planned for any version? (and is the PHP-driver likely to be updated soon after?)

        Show
        Johan Gustafsson
        added a comment - Is this feature resolved yet? If not, is it planned for any version? (and is the PHP-driver likely to be updated soon after?)
        Hide
        Ian Whalen
        added a comment -

        Johan Gustafsson this has not been completed yet, and it isn't scheduled for the upcoming 2.4 release. We will re-evaluate this for upcoming releases as we begin preparing them.

        Show
        Ian Whalen
        added a comment - Johan Gustafsson this has not been completed yet, and it isn't scheduled for the upcoming 2.4 release. We will re-evaluate this for upcoming releases as we begin preparing them.
        Hide
        bg
        added a comment -

        Very surprised I couldn't do this. Last comment Sept 2012! Any update?

        Show
        bg
        added a comment - Very surprised I couldn't do this. Last comment Sept 2012! Any update?

          People

          • Votes:
            35 Vote for this issue
            Watchers:
            26 Start watching this issue

            Dates

            • Created:
              Updated:
              Days since reply:
              8 weeks ago
              Date of 1st Reply: