Re: Convert date and time colums to datetime

On 10/19/25 09:35, Rich Shepard wrote:
> On Sun, 19 Oct 2025, Adrian Klaver wrote:
>
>> 2) If you really need a timestamp the work is already done, instead of
>> building on the fly.
>
> Adrian,
>
> As each row in the table already has both a date column and a time column I
> don't know if I 'really' need a timestamp. When would a timestamp be really
> needed?

I would say the fact you are asking is an indication you might need it.

>
>> select ('10/19/2025'::date + '07:50'::time)::timestamptz;
>
> Yes, I saw that on the doc page. This requires manually changing each
> row in
> the table rather than using a date/time condition/function to to create the
> single timestamp column. So, apparently there's not a way to modify the
> table other than by hand.

1) Again you seem to be establishing a need for combined value.

2) Not sure how you do "...date/time condition/function to to create
the single timestamp column" without creating a column?

If you meant creating a timestamp value then I point you at my original
post and:

"2) If you really need a timestamp the work is already done, instead of
building on the fly."

Doing the one time change to add a timestamp field to the table and then
do the UPDATE of date + time to populate it versus calculating it every
time you need the value. Of course moving forward you would need to
change the code that INSERTs new values to use a timestamp instead of a
date and a time value.

>
> Thanks,
>
> Rich
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com