[Qgis-user] query for Virtual Layer in relation to another layer

[Uwe Fischer]

Moin moin,

that's exactly the information I was looking for. Thanks again and sunny weekend,

Uwe


-----Ursprüngliche Nachricht-----
Von: Qgis-user [mailto:qgis-user-bounces at lists.osgeo.org] Im Auftrag von Jürgen E. Fischer via Qgis-user
Gesendet: Freitag, 4. November 2022 14:12
An: qgis-user at lists.osgeo.org
Betreff: Re: [Qgis-user] query for Virtual Layer in relation to another layer

Moin Uwe,

On Fri, 04. Nov 2022 at 13:59:35 +0100, Uwe Fischer wrote:
> great - it works as expected!! Thank you!
> How can I find out about the engine that is used and the SQL syntax 
> for virtual layers? I'd like to learn about it to be able to build 
> more queries like this one.

Well, || is the standard syntax, but there are probably also databases that will take + to concatenate strings too.  It's SQLite:

https://docs.qgis.org/3.28/en/docs/user_manual/managing_data_source/create_layers.html#supported-query-language

14.2.5.2. Supported query language

The underlying engine uses SQLite and SpatiaLite to operate.


Jürgen
 
-- 
Jürgen E. Fischer           norBIT GmbH             Tel. +49-4931-918175-31
Dipl.-Inf. (FH)             Rheinstraße 13          Fax. +49-4931-918175-50
Software Engineer           D-26506 Norden            https://www.norbit.de
QGIS release manager (PSC)  Germany                 IRC: jef on Libera|OFTC