Difference between revisions of "Useful Queries"

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(Useful Queries)
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A query to determine the total distance a bird has flown is :  
A query to determine the total distance a bird has flown for a time period is :  
 
  
 
  select sum(distance)/1000 as total_distance
 
  select sum(distance)/1000 as total_distance
 
  from gps.get_uvagps_track_speed('''<ID>''');
 
  from gps.get_uvagps_track_speed('''<ID>''');
  
or  
+
or for a fixed time period :
  
 
  select sum(distance)/1000 as total_distance
 
  select sum(distance)/1000 as total_distance

Revision as of 09:44, 27 September 2010

A query to determine the total distance a bird has flown is :

select sum(distance)/1000 as total_distance
from gps.get_uvagps_track_speed(<ID>);

or for a fixed time period :

select sum(distance)/1000 as total_distance
from gps.get_uvagps_track_speed(<ID>, '2010-01-01 00:00:00', '2011-01-01 00:00:00');


If you want to do this for all ID's at the same time you can do something like :

select device_info_serial,  (select sum(distance)/1000
  from gps.get_uvagps_track_speed(device_info_serial, '2010-01-01 00:00:00', '2011-01-01 00:00:00')) as total_distance
from gps.uva_device

For limited users :

select device_info_serial,  (select sum(distance)/1000
  from gps.get_uvagps_track_speed(device_info_serial, '2010-01-01 00:00:00', '2011-01-01 00:00:00')) as total_distance
from gps.uva_device_limited


The GROUP BY clause in SQL can be used to count the total number of measurements for each device :

select device_info_serial, count(*) 
from gps.uva_tracking
group by device_info_serial; 

and for limited users :

select device_info_serial, count(*) 
from gps.uva_tracking_limited
group by device_info_serial; 


If you want to count the number of measurements with valid GPS fixes you can add a where clause :

select device_info_serial, count(*) 
from gps.uva_tracking 
where latitude is not null 
group by device_info_serial;

If you to see want both the count of valid and invalid GPS fixes per device you can do something like :

 select device_info_serial, latitude is not null as valid, count(*) 
 from gps.uva_tracking 
 group by device_info_serial, valid 
 order by device_info_serial, valid;

and for limited users:

 select device_info_serial, latitude is not null as valid, count(*) 
 from gps.uva_tracking_limited 
 group by device_info_serial, valid 
 order by device_info_serial, valid;