[FIXED] Using the DISTINCT keyword causes this error: not a SELECTed expression

Issue

I have a query that looks something like this:

SELECT DISTINCT share.rooms
FROM Shares share
  left join share.rooms.buildingAdditions.buildings.buildingInfoses as bi
... //where clause omitted
ORDER BY share.rooms.floors.floorOrder, share.rooms.roomNumber,
         share.rooms.firstEffectiveAt, share.shareNumber, share.sharePercent

Which results in the following exception:

Caused by: org.hibernate.exception.SQLGrammarException: ORA-01791: not a SELECTed expression

If I remove the DISTINCT keyword, the query runs without issue. If I remove the order by clause, the query runs without issue. Unfortunately, I can't seem to get the ordered result set without duplicates.

Solution

You are trying to order your result with columns that are not being calculated. This wouldn't be a problem if you didn't have the DISTINCT there, but since your query is basically grouping only by share.rooms column, how can it order that result set with other columns that can have multiple values for the same share.rooms one?

Answered By - Lamak
Answer Checked By - Marilyn (JavaFixing Volunteer)