How to change the timestamp format in Postgresql to extract day part of the str?-CodePudding

I have create a datetime with type timestamp. datetime timestamp NOT NULL I am not sure why the output is like this:

I want to extract the day part. I have tried these different approach but in both cases I am getting an error. How can I fix it?

extract(DAY FROM TIMESTAMP min(to_char(u.datetime ,'YYYY-MM-DD HH24:MI'))::timestamp)

EXTRACT(DAY FROM TIMESTAMP min(to_char(u.datetime ,'YYYY-MM-DD HH24:MI')))

 date_part('day', min(to_char(u.datetime ,'YYYY-MM-DD HH24:MI')))

As mentioned in response I modified query to be like below and it does work.

extract(day from MIN(datetime)) as Day

CodePudding user response：

All you need is:

select *, extract(day from activated_at) as Day from yourTable;

What you are seeing is a timestamp formatted as text for the display. Underlying data is timestamp as you said, directly use it.