This is probably simple but I am new and really do not want to f* things up. I have already perused this page on Schema alignment but I am not sure I get it right..
I have already uploaded data on a wikibase instance, which included a number of new values for a given statement, each with many qualifiers. Then I realised I had forgotten an important qualifier, which I now need to add.
So really there could be two ways to do this: 1/ simply add the missing qualifier to the values, which requires matching properly; 2/ entirely replacing what I previously uploaded with the new values containing all qualifiers, including the previously missing one.
Since I still have my previous schema and all my data, I guess both ways can work easily. My two questions are: 1/ is there a preferred way? (down the line, it might be better to know how to safely just add elements, I guess), and 2/ how should I go about it?
@epfo sorry about the delay in replying. It's a while since I did this type of work, but I think it's OK to do either of the ways you describe... however in both cases you need to be careful on the matching as you suggest. The following is from memory so if others have advice then I hope they will chip in!
Your option (2) is simplest as you can just use the Property matching in the schema alignment BUT you can only safely use this approach if the property is unique on the entity - so assuming you've already matched the entities its worth doing "Add column from reconciled values" and pulling down the property you need to update - this way you can check if any of the entities have multiple values. If they are all unique you can just push the update replacing the property. If there are some with repeated properties, then you can filter these out before doing your first update, and then tackle them wih a more targetted schema alignment in a second run through
Hope that makes sense
Also ... EditGroups is your friend - this has saved me on multiple occasions, as no matter how careful you are everyone makes mistakes! Through EditGroups you can undo a whole set of edits from OR
All editgroups from OR can be seen at EditGroups and you can filter down to edits from a particular user by clicking the user name or adding &user=<wikidata user> on the end of the URL. Click the UID of the edit group to see the edits and Undo them if you need to
Thanks for the detailed. It was unfortunately not as smooth as I'd hoped. I first did a try-out with a facet limiting to one entity, so that I could test out, and all seemed well.
But then I realised that the property I was using was wrong, so I had to re-import everything from scratch using the new property in any case. That was evidently smooth because there were no previous records under that property.
Finally, I tried updating another property because the unit was missing, and there it all failed. As a result, all the values under that property were duplicated and I had to remove all the duplicates by hand
you can just use the Property matching in the schema alignment
You kind of lost me there. Do you mean the normal way the schema work (by dragging the properties and values) or is there something else? Because I cannot seem to find something called property matching.
its worth doing "Add column from reconciled values" and pulling down the property you need to update
That I am not yet familiar with at all. Anything I should know?
