select
	'Year' = DATEPART(YEAR, log_date),
	'Month' = DATEPART(MONTH, log_date),
	'Day' = DATEPART(DAY, log_date),
	'Hour' = DATEPART(HOUR, log_date),
	'Entries' = count(*)
from
	system_logging
where
	log_level = 'Error'
GROUP BY
DATEPART(YEAR, log_date),
DATEPART(MONTH, log_date),
DATEPART(DAY, log_date),
DATEPART(HOUR, log_date)
order by
	DATEPART(YEAR, log_date),
	DATEPART(MONTH, log_date),
	DATEPART(DAY, log_date),
	DATEPART(HOUR, log_date)