[Qgis-user] 1 to many relationship does not allow to display the many

[Janneke van Dijk]

Hi Alexandre,
Also thanks for the quick response!

What I can do with the DB manager is:
>
>
>     select location_point.geom, asset_point.assetid, location_point.fid
>     from asset_point cross join location_point on
>     asset_point.locationid =
>     location_point.fid
>
>
> This should work, but why the CROSS JOIN? a simple join should be enough.
I first had a simple join, then saw an example of a cross join and tried 
that in the hope that that would make a difference.
>
>     this query yields 170 records, corresponding with the number of
>     records
>     in the assets table. When I load as a new layer, the result is a
>     table
>     with 170 records, but 100 filtered (the total number of locations). I
>     chose assetid to be the unique id (which it is).
>
>     Is that expected behaviour? How else can I display all the records in
>     the assets table (instead of only the 100 that are filtered now)?
>     I know
>     I can do it in Postgres but for my purpose now I don't want to go
>     there.
>
>
> An alternative is to create a relation between the two tables, the 
> assets will show in the location feature form. You can even add more 
> assets to a certain location.
I have a relationship, and the assets will show up in the form of the 
location when you click on the location (including locations with 
several). However, it doesn't allow me to label the location with 
information from the assets, or create symbology based on asset information.

What puzzles me is that the query results in 170 records, I would have 
expected the geometry to be joined to each of the 170 attribute records 
and then be displayed - so where does the filter with a 100 suddenly 
come from? (Is this a bug?)

As a work around I think I could get xy coordinates of the location, 
then join them to the assets, export to csv and import again as a 
delimited text layer for display purposes.

I was hoping someone could either explain why this result makes sense, 
or that I just made a mistake somewhere...any more thoughts?

Thanks for sharing your thoughts!

Janneke

>
> Alexandre Neto
>

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