[Qgis-user] Applying a label to a point in a series of points

[Andrea Giudiceandrea]

Hi Phil and list,
if I've understood correctly your problem, I think you can use the 
following expression in order to display a label (e.g. the aircraft id) 
only for the first (i.e. having the minimum timestamp value) and the 
last (i.e. having the maximum timestamp value) point for each aircraft id:

if("TIMESTAMP" = maximum("TIMESTAMP","AC_ID") OR "TIMESTAMP" = 
minimum("TIMESTAMP","AC_ID"), "AC_ID",'')

Regards.

Andrea Giudiceandrea

> Phil phillor9 at gmail.com
> Thu Nov 27 13:56:06 PST 2025

> If I have logged the 
> same aircraft multiple times then only the first last points should be 
> labelled.

> TIMESTAMP,AC_ID,LAT,LON
> 2025-11-21 23:55:36,71BE35,-33.962925,151.182806
> 2025-11-22 00:24:00,E80445,-33.958462,151.178686
> 2025-11-22 00:37:30,A47FDE,-33.971508,151.182120