overload() problem

I'm trying to write a class for abstracting some aspects
of database programming and am running into a problem:

http://hashphp.org/pastebin.php?pid=567

The code works fine for the first instantiation of the DbTable (Product)
class,
but not the second. It seems clear that the reason it works the first
time is that overload() isn't called until after describe() in DbTable's
constructor,
so DbTable can "see" its actual properties. The second time it's
instantiated, the
class is already overloaded, so it can't and describe() fails to
populate the columns
array. Unfortunately, seeing the problem is not helping me see the
solution =P

Does anyone have an idea for a workaround for this?

BTW, the DbTable class isn't tied to any particular table, so it should
be easy to test against
any spare PostgreSQL tables you might have lying around (just change the
test code).


TIA,
Cliff

Cliff Wells wrote:

> I'm trying to write a class for abstracting some aspects
> of database programming and am running into a problem:
>
> http://hashphp.org/pastebin.php?pid=567


Well, I kept hacking at it and changing the describe() method from this:


// get a description of a table
function describe($table)
{
$db = $this->db;

$q = $db->prepare("SELECT * FROM $table LIMIT 0");
$result = $db->execute($q);

foreach ($result->tableInfo() as $c)
$this->columns[$c['name']] = NULL;
}


to this:


// get a description of a table
function describe($table)
{
$db = $this->db;
$columns = array();

$q = $db->prepare("SELECT * FROM $table LIMIT 0");
$result = $db->execute($q);

foreach ($result->tableInfo() as $c)
$columns[$c['name']] = NULL;

$this->columns = $columns;
}


seems to fix it. I can't see any reason why other than what appears to
be general PHP brokenness.
If anyone has a rational explanation as to why this is so I'd be
grateful to hear it.

Regards,
Cliff