Thanks for the suggestion Karl. I have used row_number() also but in the case of dumping vertex points from a line, multiple points are created from each line feature and therefore, the row_number is repeated for all points on the same line.
Árni Árni Geirsson *Alta ehf* // +354 582 5000 // +354 897 9549 On 12 April 2017 at 09:45, Karl Magnus Jönsson < karl-magnus.jons...@kristianstad.se> wrote: > Hi! > > I’ve used something like this to get unique Ids: > > SELECT row_number() OVER (ORDER BY s.omrade_id, s.kod) AS id, …. ORDER BY > s.omrade_id, s.kod; > > > > If the ordering isn’t necessary I guess you can skip that. > > > > https://www.postgresql.org/docs/current/static/functions-window.html > > > > > > *Karl-Magnus Jönsson* > > > > *Från:* Qgis-user [mailto:qgis-user-boun...@lists.osgeo.org] *För *Árni > Geirsson > *Skickat:* den 12 april 2017 11:34 > *Till:* qgis-user@lists.osgeo.org > *Ämne:* [Qgis-user] Unique IDs in a PostGIS view > > > > I am trying to create a view that extracts vertices from lines using > ST_DumpPoints and to get unique IDs I have set up a sequence to generate > the numbers using nextval(). The query executes normally in the DB Mananger > and I see the results as a table in the table view. However, when I attempt > to load the results of the view as a layer in QGIS, I get an error: > "Database error: ERROR: cannot execute nextval() in a read-only > transaction". No features are loaded. > > Are there any smart tricks out there to work around this or other means of > generating the IDs? > > > > Árni Geirsson >
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