I am managing a conference with about 400 poster contributions.
The chair of the conference wishes to order the poster boards according to the last name of the poster presenter.
I feel that it should be possible to automate this via indico shell since there is Contribution.board_number in the API.
So I can make the query for posters
event = Event.get_one(<event_id>) posterQuery = Contribution.query.with_parent(event).filter(Contribution.type_id == <poster_contrib_type_id>)
And I can sort by say, the poster title
But I cannot sort by the last name of the speaker since this would give a list of speakers (even though we only have one speaker per contribution in our event, in principle there can be multiple speakers). The actual error is: SQL expression object or string expected, got object of type <type ‘property’> instead.
posterQuery.order_by(Contribution.speakers).all() # does not work Contribution.get_one(<id>).speakers.last_name # is what I want to sort by
After some discussion with others who know more about SQL, it seems that I need to perform a join of some kind. I tried then
which seems to work. But what I found confusing was
posterQuery.count() # 416 posterQuery.join(ContributionPersonLink).count() # 2217
I thought the join would only take the contributions that are posters and do an inner join, but that doesn’t seem to be the case. So then I tried:
posterQuery.join(ContributionPersonLink).filter(ContributionPersonLink.is_speaker).count() # 416
which seems to generate the right count. Then I tried to sort this by last name:
This time I am able to get an output. But what looks weird is when I check the speakers:
(what I use for checking the output)
testList = PosterQuery.join(ContributionPersonLink).filter(ContributionPersonLink.is_speaker).order_by(ContributionPersonLink.last_name).all() for contrib in testList : cid = contrib.id contribspeakers = contrib.get_one(cid).speakers print contribspeakers
It seems to me that the first 40 entries were sorted according to the last name of the speakers, but the rest are not. I am rather confused about why.
To return to the task I wanted to do, I am now going to do it through more Python rather than getting the sorted list directly from the database. But I would be interested to know if there is a better way of doing it (or better way of doing any of the steps along the way).