what is a "valid link resource"?

In response to PJ <af.gourmet@videotron.ca>:

In trying to learn both php and postgresql as a novice, I am trying to
debug a double migration of our old website from php4 to php5 and from
postgres 7.4 to 8.3.
I am running freebsd 7.0 on two machines and sometimes debugging from a
Windows XP.
The migrations themselves went fine; now to debug and make them actually
work so I can tear this thing apart and rebuild with a new concept,
design & implementation.
So far, I am getting this error:

"pg_exec(): supplied argument is not a valid PostgreSQL link resource"
in this code (third line -->)

...snip
function SQLQuery( $query ) {
global $dbh,$curr_row,$result_hash;
if( !($r=pg_exec($dbh, $query)) ) {
if (error_reporting()>0) {
echo "<hr>SQL error (".pg_ErrorMessage($dbh).")<br>in
($query) <hr>";
}
return 'error';
}
$curr_row[$r] = 0;
$rows=@@pg_numrows( $r );
if(eregi("insert",$query)) {
#list($f1,$f2)=split('INTO',strtoupper($query));
$f=array();
if(eregi('(.*)into(.*)',$query,$f)) {
list($tablename,$bullshit)=split("\(",$f[2]);
$result_hash[$r]=$tablename;
}
}
return $r;
}
snip ...

What, then, is a valid link resource? is it the strings or their
content? I have been trying to figure out if pg_exec is valid in
postrgres or should it be replaced by another function? There seem to be
a number of these functions that are returning the same error...
I have also not been able to determine the content of the strings $dbh,
$query or most other strings while debugging with eclipse, trying with
phped, devphp .... I seem to be connecting to the remote server (freebsd
with apache2.2.8 on LAN)

Note that there is a pgsql+php mailing list that may be more helpful
with your issues.

However, I would suggest adding a var_dump($dbh) prior to the pq_exec()
call as a debugging step. The output should say that $dbh is a resource.
If it does not, then the connection attempt failed, or the value of that
variable was lost or something else earlier in your code.

A resource is a special kind of PHP variable, it is not a string, it is
a resource, with a resource ID. It points to internal PHP data structures
that do special things (in this case, point to a PG connection)

You're using the correct commands, but the data your passing them doesn't
appear to be correct. Perhaps add some debugging around the pg_connect()
to ensure it's working properly.

--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/

wmoran@collaborativefusion.com
Phone: 412-422-3463x4023