Question

I have a table with log data, of this form:

Date        Time    Device  Configuration
01.01.2012  12.00   8193    12345
01.01.2012  12.15   8193    12345
01.01.2012  12.35   8193    22375
01.01.2012  12.37   7191    32335

I need the maximum Configuration, on each Day, for each device:

Date        Device  Configuration
01.01.2012  8193    22375
01.01.2012  7191    32335

I can create a cross product of Dates-devices to get all Date-device combinations,
but how do i find the maximum configuration for each Date-Device pair?

Answer 1

Just group by both Date and Device, get the MAX and you’re done.

SELECT Date, Device, MAX(Configuration) AS Configuration
FROM logData
GROUP BY Date, Device