Hi everyone,
Could someone help me with this question please? I have a table with
four columns:
- gps_id (primary key)
- date_time
- crimes_link (foreign key)
- osgb36_geom
The data in the table involves lots of gps tracks of different
journeys. They are grouped into journeys by the 'crimes_link' field.
So for example the first 50 rows have an identical 'crimes_link'
field, then the next 50 rows a different value in 'crimes_link', then
the next 50 rows a different one, etc. What I would like to do is to
select the beginning location of each journey. This query gives me the
date_time of the beginning of the journey:
SELECT crimes_link, MIN(date_time)
FROM camdengps3
GROUP BY crimes_link;
However I need to add the osgb36_geom column into the query and am unable too.
Any ideas how to do this please?
Thank you
James Smith
