Postgresql problems

Question

i have a table like this:

name   used   time  
asd    10     15:00  
bsf    15     15:00  
asd    20     14:55  
bsf    0      14:55

i need to make a query that returns values like this: the result i need for the grafana timeseries is:

total   tm
25       15:00
20       14:55 

i've tried using:

SELECT
 DISTINCT(time) as tm,
 sum(used) as total
FROM table
GROUP BY tm

but that doesnt works everything i try gives me the repeated time values

Answer 1

I managed to solve the problem by using the date_trunc() function to select the time value since the column was of type timestamptz the query ended up looking like this

select
 date_trunc('minute', time) as tm,
 sum(used) as total
from
 table
group by
 tm