Steve Crawford wrote:
Dan Harris wrote:
I'm trying to write a function that can do a select on an integer value
from a table and subtract that value from current_timestamp.
Let's say I have a table called users and a field called tz_offset..
I want my function to do something like :
select current_timestamp - '( select tz_offset from users where userid =
? ) hours'::interval
Obviously this syntax is incorrect, but I'm not quite sure how to do the
subquery and make the integer result of it part of the quoted interval
expression.
Any tips?
You don't need to make it part of the quoted expression - just multiply
an interval by your integer. Using your version, try something like:
select current_timestamp - '1 hour'::interval * ( select tz_offset from
users where userid = ? )
But this is actually wrong because the returned time is still in your
current timezone - just offset by X hours.
Thanks for the extra explanation here. I think I'll be OK because the timezone
offset comes directly from the browser. I grab it via javascript and as long as
their system timezone offset is set correctly, the dates will be displayed
relative to them. I do understand that I will have to do more work if I want to
display their dates to other users in different timezones correctly.
-Dan
