Re: Date Manipulations - Mailing list pgsql-php

Well, what I was trying to do was this:

I need to insert records into a rate table. The table has start and end
dates (fdate, tdate) and there are no gaps in the dates allowable. We have
things like 4/1/2001 - 4/15/2001, the next record _MUST_ have 4/16/2001 as a
start date ... and so on. The last record has 12/31/2999 as an end date
(meaning forever, until the Y3K bug hits, but I don't plan to be in the
programming business by then).
When I insert a record, I have to find at least one other record, either to
determine what my new end date should be (when I insert it before the first
record) or, I need to adjust the end date of an existing record to one day
before my new record's start date.
I do this by:
$OldDate = pg_result( $FindOldRate, 0, 4 );
and
update ... set rate.tdate = ('$NewDate'::date - 1)::date ...

What I found is that I also need to do:
Insert ... values( ('$NewDate'::date + 0)::date ...

the + 0 (as in ZERO) gets me - if I do it this way, it works, if I leave it
off, it complains that it has a bad external representation (or something
like that). But the field has the format "YYYY-MM-DD" ... it just has me
puzzled ... I can manage with the work-around, I just don't understand why,
and I would like to know why (even if this knowledge serves no purpose ;-).

Best regards,
Chris


----- Original Message -----
From: "Mitch Vincent" <mvincent@cablespeed.com>
To: "Chris Ruprecht" <chrup999@yahoo.com>; "p-php"
<pgsql-php@postgresql.org>
Sent: Wednesday, July 11, 2001 11:39 AM
Subject: Re: [PHP] Date Manipulations


> Well, it depends on what you're trying to do :-)
>
> You can add days an arbitrary date in a number of ways , I often let PG
> handle it though (as you are)..
>
> I generally do something like
>
> SELECT ('05-05-2001'::date + '5 days'::interval)
>
> Or something like that if I need X days ahead or behind date Y...
>
> ----- Original Message -----
> From: "Chris Ruprecht" <chrup999@yahoo.com>
> To: "p-php" <pgsql-php@postgresql.org>
> Sent: Wednesday, July 11, 2001 10:06 AM
> Subject: [PHP] Date Manipulations
>
>
> > Hi all,
> >
> > Currently, when working with dates, I use constructs like
> >
> > ('$NewDate'::date + 5)::date
> >
> > this seems a little clumsy to me and I was wondering if there was an
> easier
> > way of doing this.
> >
> > Best regards,
> > Chris
> >
> >
> >
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