Re: Constructors for dates, times, and timestamps

"Andrew T. Robinson" <atr(at)nmi(dot)net> writes:
> The following work under DB/2, but I can find no analog in the
> PostgreSQL documentation:

> time('00:00:00') [there is to_date() and to_timestamp(), but no
> to_time()?]

Write it as a cast, either SQL-spec CAST() or PG :: notation.

regression=# select '00:00:00'::time;
time
----------
00:00:00
(1 row)

In many situations PG also accepts the same function-like notation for
specifying casts that DB/2 seems to be using, but in this particular
case it doesn't work because TIME(n) is a datatype specification
according to the SQL spec, and the special syntax needed for that
conflicts with this usage.

> timestamp(u.date, u.time) [where u.date is of type DATE and u.time
> is of type TIME]

You can add a date and a time to get a timestamp:

regression=# select '3-1-2007'::date + '12:34'::time;
?column?
---------------------
2007-03-01 12:34:00
(1 row)

regards, tom lane