Postgresql每小时最大和最小值

Question

我想在postgresql中每小时返回最大/最小值。这是我每天最大/分钟的代码。

@"SELECT MAX(psa_value), MIN(psa_value),DATE(psa_date) FROM public.ps_analog Where psa_psl_id_name='A6' GROUP BY DATE(psa_date)";

Answer 1

您要找的是date_trunc():

SELECT DATE_TRUNC('hour', psa_date) as hh, MAX(psa_value), MIN(psa_value)
FROM public.ps_analog 
WHERE psa_psl_id_name = 'A6'
GROUP BY hh;