Thread: RE: [SQL] timespan arithmetic

I'm not certain this will work, but
try:SELECT * FROM table   WHERE loaded_time::datetime >= now()::datetime - '1
days'::timespan  ORDER BY loaded_time DESC;


> -----Original Message-----
> From:    David Rose [SMTP:David.R.Rose@disney.com]
> Sent:    Monday, July 26, 1999 6:01 PM
> To:    pgsql-sql@postgreSQL.org
> Subject:    [SQL] timespan arithmetic
> 
> Hello.
> 
> I recently posted this question on pgsql-novice and received no
> answer.  Undaunted, I'm trying again on pgsql-sql.  Perhaps someone
> knows at least where to start looking for an answer to this problem.
> It's not in the FAQ, and I couldn't find an answer in the mailing list
> archives.
> 
> I have a table that includes a column of type timestamp.  I'd like to
> formulate a query that returns, say, all rows no more than 24 hours
> old, based on the timestamp.  Trial and error got me this far (and a
> perusal of the mailing list archives confirmed it):
> 
>   SELECT * FROM table 
>   WHERE loaded_time >= 'now'::timestamp - '1 days'::timespan
>   ORDER BY loaded_time DESC;
> 
> This works fine in PostgreSQL 6.4.2.  However, another user of my
> software, who has PostgreSQL 6.3.2, reports that he gets the following
> error message:
> 
>   ERROR: There is no operator '-' for types 'timestamp' and 'timespan'
>   You will either have to retype this query using an explicit cast, or you
>   will have to define the operator using CREATE OPERATOR
> 
> 
> So.  Is there a correct solution to this problem that works for all
> versions of PostgreSQL--or at least, PostgreSQL versions 6.3.2 and
> higher?  Barring that, is there at least a solution at all for 6.3.2,
> which may or may not be different from the solution for 6.4.2 and
> higher?
> 
> Many thanks.
> 
> David
> 

Jackson, DeJuan writes:
> I'm not certain this will work, but
> try:
>     SELECT * FROM table 
>       WHERE loaded_time::datetime >= now()::datetime - '1
> days'::timespan
>       ORDER BY loaded_time DESC;

Excellent!  That did the trick.  Many thanks!

(I feel a little stupid for not thinking of trying 'datetime' by
myself--I was running into a dead end with 'reltime'.  Oh well.
Thanks!)

David