How to convert date to timestamp(DD-MON-YYYY HH24:MI:SS.FF format) in oracle?

Question

I tried below query but its not working

select 
    TO_TIMESTAMP(ColumnName(Data type Date), 'DD-MON-YYYYHH24:MI:SS.FF') 
from TableName 
where Changedate>='01-Dec-2015'

*I need the result without AM/PM indication. Result will be 15-DEC-2015 15:16:42.045016

Answer 1

If I got your question right you need the output in the mentioned Format. That would be a conversion to character

select to_char(cast(sysdate as timestamp),'DD-MON-YYYY HH24:MI:SS.FF') from dual

Of course in the above the FF would also always be 000000

But if you have a timestamp variable you would not cast

select to_char(systimestamp,'DD-MON-YYYY HH24:MI:SS.FF') from dual