Groupe par YYYYMM de la colonne AAAAMMJJ int - Postgresql

Question

Je date au format aaaammjj dans une colonne int et je voudrais groupe par mois soit yyyymm.I've essayé deux versions ci-dessous la

select to_char(to_timestamp(create_dt),'YYYYMM'),count(*) from table_name 
group by to_char(to_timestamp(create_dt),'YYYYMM') 
order by to_char(to_timestamp(create_dt),'YYYYMM') desc 

ET

select to_char(create_dt,'YYYYMM'),count(*) from table_name 
group by to_char(create_dt,'YYYYMM') 
order by to_char(create_dt,'YYYYMM') desc 

Answer 1

select create_dt/100, count(*) 
from t 
group by 1 
order by 1 desc 
limit 6 

Answer 2

Imaginé, toute autre manière serait utile.

select substring(create_dt::int8,1,6),count(*) from table 
group by substring(create_dt::int8,1,6) 
order by substring(create_dt::int8,1,6) desc 
limit 6;