[postgis-users] PostGis introduction doc code block seems wrong....

Bo Victor Thomsen bo.victor.thomsen at gmail.com
Thu Apr 21 02:12:39 PDT 2022


Am I the only one that get "semantic itch" looking at the UPDATE 
expression? I would prefer it like this:

*UPDATE*nyc_neighborhoods

*SET*geom_invalid=geom,

geom =ST_MakeValid(geom) *WHERE**NOT*ST_IsValid(geom);

where you save the original "geom" value into another column 
"geom_invalid" before rectifying it and saving it into the original column.

Disclaimer: I have no clue about the internal methods of the SQL 
interpreter and how and in which order it assigns values.

Med venlig hilsen / Kind regards

Bo Victor Thomsen

Den 20-04-2022 kl. 16:59 skrev Regina Obe:
>
> Thanks for the errata.  Corrected now.
>
> *From:*postgis-users [mailto:postgis-users-bounces at lists.osgeo.org] 
> *On Behalf Of *Jian He
> *Sent:* Wednesday, April 20, 2022 5:12 AM
> *To:* PostGIS Users Discussion <postgis-users at lists.osgeo.org>
> *Subject:* [postgis-users] PostGis introduction doc code block seems 
> wrong....
>
> 23. Validity — Introduction to PostGIS 
> <https://postgis.net/workshops/postgis-intro/validity.html>
>
> last code block,
>
> /-- Fix invalid and save the original/
> *UPDATE*nyc_neighborhoods
> *SET*geom =ST_MakeValid(geom),
> invalid_geom =geom
> *WHERE**NOT*ST_IsValid(geom);
>
> I think it should be:
>
> /-- Fix invalid and save the original/
> *UPDATE*nyc_neighborhoods
> *SET*geom =ST_MakeValid(geom),
>       geom_invalid=geom*WHERE**NOT*ST_IsValid(geom);
>
>
> _______________________________________________
> postgis-users mailing list
> postgis-users at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/postgis-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20220421/49dee97c/attachment.html>


More information about the postgis-users mailing list