pg.ddx.io  pgsql-interfaces@postgresql.org mailing list archive  
help / color / mirror / Atom feed
From: Gene Selkov, Jr. <selkovjr@mcs.anl.gov>
To: JT Kirkpatrick <jt-kirkpatrick@mpsllc.com>
To: pgsql-interfaces@hub.org
Subject: Re: [SQL] perl and postgres. . .
Date: Wed, 21 Apr 1999 15:36:08 -0400
Message-ID: <199904212036.PAA20785@antares.mcs.anl.gov> (raw)
In-Reply-To: <01BE8BF0.2DAA4CE0.jt-kirkpatrick@mpsllc.com>

> I am trying 
> $query="select max((userseq) from dataentry;";
> $result=$conn->exec("$query");
> $userseq=($result->getvalue(0,0));
> 
> * I need the value in a variable name other than $result. . .
> 
> If I try
> $query="select max((userseq) from dataentry;";
> $result->getvalue(0,0);
> $userseq=$result;
> 
> it bombs.  Ahhh, the frustrations of being new to this!  

Now I see what your problem is. You missed the whole point. $result is
not a variable, it is an object reference, so is $conn. The exec()
method of $conn (or rather, that of the object referenced by $conn)
returns the result object. You normally access the object's data
through its methods, in this case, getvalue(), fetchrow(), etc. -- see
the Pg doc for the full list.

So the following simply copies the reference to the result object into
$userseq, and that may bomb, depending on how you use it further:

> $userseq=$result;

The following the value you need, but it since there is no explicit
assignment, it is getting lost:

> $result->getvalue(0,0);

What you needed was

$userseq = $result->getvalue(0,0);

And again, the manual for Pg has complete examples. Note the code you
need to add to check for errors that may result from each method call.


--Gene



view thread (4+ messages)

Message-ID: <199904212036.PAA20785@antares.mcs.anl.gov>
Permalink:  ../199904212036.PAA20785@antares.mcs.anl.gov/
Also on:    postgresql.org/message-id/199904212036.PAA20785@antares.mcs.anl.gov

 · 

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-interfaces@postgresql.org
  Cc: selkovjr@mcs.anl.gov, jt-kirkpatrick@mpsllc.com, pgsql-interfaces@hub.org
  Subject: Re: [SQL] perl and postgres. . .
  In-Reply-To: <199904212036.PAA20785@antares.mcs.anl.gov>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox