suplied argument not valid mysql sql resource

[bilibytes]

hi,
i tried to create sort of a db abstraction layer in order to be able to change of database (Mysql | oracle | pg |...).

i implemented that on a obejct oriented way.

i made a sql factory in PHP which simply instanciate classes whose methods wrap the php normal sql functions like mysql_query() mysql_num_rows( ) pg_query()...
one of these methods is num_rows()

i implemented it this way:

public function num_rows($result)
{
    return mysql_num_rows($result);
}

the problem is it will generate a mysql error:
mysql_num_rows( ): supplied argument is not a valid MySQL result resource in ...

so i thought it could be because i'm not passing the argument as a reference so i changed that to:

public function num_rows(&$result)
{
    return mysql_num_rows($result);
}

but it still returns that error.

how should that be done?

do you have any suggestions?

by the way how can i know if an insertion succeed, without the "or die(mysql_error )"?

please let me know

thank you!

best regards

bilibytes

[code green]

Echo out the value of $result.
It should be something like #2.
If not, as is almost certainly the case the result resource is not in $result.
We would need to see more code to repair this.

Also a reminder this only works with SELECT queries

On a design point I have a similar class.
But because the result resource may be used within a number of methods
I place it in a class member variable

//Private members
private $result;

function xxxxxx()
$this->result = mysql_query()

function xxx()
mysql_num_rows( $this->result)

[bilibytes]

Thank you for your time.

but i managed to solve it, it was a problem of the mysql_query() wrapper.

public function query($sql_code)
{
    return mysql_query($sql_code, $this->link) or die(mysql_error());
}

i put the or die(mysql_error ()) while debugging and that was causing all the problems.
What i still don't understand is why it happens.. what does it return when i put or die(mysql_error ())
mysql_error() should not get triggered as when i don't put the or die()... the query works perfectly.

ahhh maybe it returns a boolean?

like: "return the evaluation of these two conditions, if one is true retrun true?"

i think that may be the reason

best regards