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For the timestamps the time column being queried may need to be converted into a unix timestamp to make a comparison valid. MySQL's timestamp function is UNIX_TIMESTAMP( timecolumn )
Example: SELECT * FROM interface WHERE UNIX_TIMESTAMP(lastUpdate) >= time.start AND UNIX_TIMESTAMP(lastUpdate) < time.end AND customerName = user.customer
groupby:
If the data returned from the SQL statement needs to be grouped (for summing or counting, works much like SQL GROUP BY) use this field to specify the group, as an array, order matters. This works in tandem with the aggregation function to produce results. Just like in an SQL GROUP BY each column requires a function to aggregate it's result.
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