On Thursday, 20 December, 2018 17:32, Jens Alfke <j...@mooseyard.com> wrote:
>> On Dec 20, 2018, at 4:21 PM, Jungle Boogie <jungleboog...@gmail.com> wrote: >> select od_reading from mileage where car='foo' limit 1 >> select od_reading from mileage where car='bar' order by od_reading >> desc limit 1 >Note: the first query should use “order by od_reading”, otherwise the >order is undefined. >A clearer way to specify these is > select min(od_reading) from mileage where car=‘foo’ > select max(od_reading) from mileage where car=‘foo’ >> How do I subtract the last query from the first query to determine >> how many miles were driven? >It’s super simple: >(select od_reading from mileage where car='foo' limit 1) - (select >od_reading from mileage where car='bar' order by od_reading desc >limit 1) Or, more simply, select max(od_reading) - min(od_reading) as miles_driven from mileage where car='bar'; --- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
