[Qgis-user] PostGIS Views in QGIS 3.10

[Alexandre Neto]

At least, 4 things can go "wrong" between QGIS and postgis views, which
result in the yellow warnings.

1 - theres no "id" column or it has repeated values;

fix it or create a identifiers on the fly with rownumber() over() as id

2 - QGIS was not able to guess which column to use for unique identifiers;

Call it "id" and make sure it's the first column in the result.

3 - The view returns columns with the same name;

Use alias to change the column names.

SELECT a.id, a.name, b.name as name2

4 - The view transform the original geometries (for example because you
used a function like st_buffer around it) and QGIS does not know what
geometry type and SRID to use:  cast the geometry columns with expected
geometry type. Like this:

st_buffer(geom, 10)::geometry(POLYGON, 3763)

Hope it helps.

Alexandre Neto
QGIS Support
www.qcooperative.net

A quinta, 14/05/2020, 09:14, Andreas Neumann <a.neumann at carto.net> escreveu:

> Hi Vera,
>
> As far as I know, the yellow triangle means that either something is wrong
> with the layer, or that it needs a user input, such as "choosing a primary
> key column" in case of a view.
>
> It basically means that the layer can't be loaded, unless the user
> provides a hint to QGIS how to correctly load the layer.
>
> I don't think you can configure QGIS to not display these yellow triangles
> for views. I also think they are useful indicator to the users, that they
> need to do something.
>
> It could also be a missing SRID, or something else.
>
> Andreas
>
>
> Am 14.05.20 um 09:22 schrieb Vera Diaz-Köhli:
>
> Hello
>
>
>
> We have made some views in our PostGIS-Database, so that it is easier for
> our users to access the data.
>
> The views have a column with a unique id ( Y ID).
>
>
>
> In the «Add PostGIS-Layer» dialog, all those view  are listed, with the
> field «Object-ID» filled in correctly ( > ID) and they can be added to the
> map. However, there’s a little yellow triangle in front of their names,
> which only disappears, when I click in the field «Object-ID».
>
>
>
> How can I get rid of those yellow triangles? They are quite confusing for
> our user, even though the views do work…
>
>
>
> Thanks in advance
>
> Vera
>
>
>
>
>
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