PHP OOP moving arrays around functions?

eco · 01-19-2009, 04:59 AM

Hi guys,

I'm trying to get the hang of PHP OOP and am at a loss on what to do next.

I created two classes
Db.php
Tables.php

The idea is that I send an SQL query to the Db class which connects to the database and returns the result in an array.

I then need to send the array to the Tables class to print out the results in an html table.

Problem is, I can't seem to get any data out of $data. How would you start writing the Tables class to extract data from the array?

Can this be done?

Here is a sample of what I did:

index.php

Code:

<?php

require_once 'classes/Db.php';
require_once 'classes/Tables.php';

$q1 = new Db;
$data = $q1->ReturnSqlQuery("SELECT User, Host FROM user;"
                                                        );
$t1 = new Tables;
$t1->UserHost($data);

Db.php

Code:

<?php

Class Db
{
        private $_host = "localhost";
        private $_user = "testuser";
        private $_pass = "test";
        private $_db   = "mysql";

        // Will need a new class Error to handle all errors

        private function ConnectToDatabase()
        {
                $link = mysql_connect($this->_host, $this->_user, $this->_pass);
                if (!$link) {
                die('Could not connect to the server: ' . mysql_error());
                }

                $db_selected = mysql_select_db($this->_db, $link);
                if (!$db_selected) {
                        die ('Could not connect to the database"' . $this->_db ." get error: " . mysql_error());
                }
        }

        private function DisconnectFromDatabase()
        {
                mysql_close($link);
        }

        public function ReturnSqlQuery($sql)
        {
                self::ConnectToDatabase();
                $result = mysql_query($sql);

                if (!$result) {
                        $message  = 'Invalid query: ' . mysql_error() . "\n";
                        $message .= 'Whole query: ' . $query;
                        die($message);
                }

                // return the result to a function that will build the right table.
                return $result;

        //      self::DisconnectFromDatabase();
        }
}

eco · 01-19-2009, 06:57 AM

Quote:

$result = mysql_query($sql);
return $result;

I think I see where I am getting things wrong. I am assuming that the above returns an array but it seems the only way to extract the data from within $result is through the following... so what is in $result?

Code:

while ($row = mysql_fetch_assoc($result)){
    echo "$row[User] - $row[Host]<br>";
}

So can I restrict the handling of database and database data to the Db class or do I have to have the equivalent of the above to extract the SQL result into my tables?

Am I doing this all wrong?

Guttorm · 01-19-2009, 07:53 AM

Hi

mysql_query returns a resource which is not an array. Why not just fetch all the rows and return an array instead? That way the database stuff will be in the Db class and not other places.

Instead of

PHP Code:



return $result;

PHP Code:



$rows = array(); 
while ($row = mysql_fetch_assoc($result)) 
  $rows[] = $row; 
mysql_free_result($result); 
return $rows;

eco · 01-19-2009, 08:07 AM

Precisely what I was after.
Thank you Guttorm