[QGIS-Developer] DB-manager and large query results (for time manager)

[Raymond Nijssen]

On 25-08-2020 10:27, Giovanni Manghi wrote:
> Hi Raymond,
> 
>> There's a question on a Dutch geo forum about a join query in DB-Manager
>> that does not return data, but an error without message instead. PG
>> Admin runs the query with he expected results, so it seems ok.
> 
> I have seen this type of problem in the past, but now I can't recall
> the exact details of my use case, can you post somewhere the data and
> the query?. More recently there was a similar issue, DB Manager
> running a query and returning 0 results, while actually the query
> returned more than that, but I think this is fixed. Recently seems
> also that DB Manager is very slow running queries that on other
> programs (i.e. pgadmin or dbeaver) take much less time.
> 
> cheers!
> 
> -- G --
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Hi Giovanni,

Thanks for your reply.

The queries and data can be found in the tread and I added the link. But 
as this is all in Dutch it might be hard for you to figure it out.


The data sources are these:

https://geodata.rivm.nl/covid-19/COVID-19_aantallen_gemeente_cumulatief.csv3

https://geodata.nationaalgeoregister.nl/wijkenbuurten2019/wfs?service=WFS2
(layer: gemeenten2019)


and the query:

select c.*, g.geom, g.inwoners
from covid19 as c
join gemeenten_bewerkt as g
on c.municipality_code=g.code;


I'm not used to the DB-manager as I prefer writing queries in DBeaver 
for creating new tables or views. When they seem right I open them in 
QGIS. DB-manager always feels a bit like a black box in between the DB 
and QGIS.

Raymond