How to do round correctly in postgresql: ERROR: function round(double precision, integer) does not exist?

Question

PostgreSQL

wrote a request

select
              'request_median_duration' as metric_name,
              EXTRACT(EPOCH FROM request_median_duration)/60 as metric_value,
              TO_CHAR(NOW(), 'YYYY-MM-DD HH:MM:SS') as push_dttm
              from mp_statistics

need to round up to 2 decimal places
tried to do so

select
              'request_median_duration' as metric_name,
              ROUND(EXTRACT(EPOCH FROM request_median_duration)/60,2) as metric_value,
              TO_CHAR(NOW(), 'YYYY-MM-DD HH:MM:SS') as push_dttm
              from mp_statistics

an error is returned

SQL Error [42883]: ERROR: function round(double precision, integer) does not exist
  Подсказка: No function matches the given name and argument types. You might need to add explicit type casts.
  Позиция: 94

got out so

select
              'request_median_duration' as metric_name,
              ROUND(EXTRACT(EPOCH FROM request_median_duration)/60*100)/100 as metric_value,
              TO_CHAR(NOW(), 'YYYY-MM-DD HH:MM:SS') as push_dttm
              from mp_statistics

what is an even more elegant option?

Answer 1

found a way to do type conversion via CAST

select
              'request_median_duration' as metric_name,
              round(cast(EXTRACT(EPOCH FROM request_median_duration)/60 as numeric),2) as metric_value,
              TO_CHAR(NOW(), 'YYYY-MM-DD HH:MM:SS') as push_dttm
              from mp_statistics