PHP MySQL Shopping Cart Tutorial - Database Abstraction

<?php
require_once 'config.php';

$dbConn = mysql_connect ($dbHost, $dbUser, $dbPass) or die ('MySQL connect failed. ' . mysql_error());
mysql_select_db($dbName) or die('Cannot select database. ' . mysql_error());

function dbQuery($sql)
{
return mysql_query($sql) or die('Query failed. ' . mysql_error());
}

function dbAffectedRows()
{
global $dbConn;

return mysql_affected_rows($dbConn);
}

function dbFetchArray($result, $resultType = MYSQL_NUM)
{
return mysql_fetch_array($result, $resultType);
}

function dbFetchAssoc($result)
{
return mysql_fetch_assoc($result);
}

function dbFetchRow($result)
{
return mysql_fetch_row($result);
}

function dbFreeResult($result)
{
return mysql_free_result($result);
}

function dbNumRows($result)
{
return mysql_num_rows($result);
}

function dbSelect($dbName)
{
return mysql_select_db($dbName);
}
?>

How to use it ?

Below you can see an example on how to use this database abstration library. The first one is using PHP database function directly :

<?php
require_once 'config.php';

$conn = mysql_connect($dbHost, $dbUser, $dbPass);
mysql_select_db($dbName);

$sql = "SELECT *
FROM tbl_product
ORDER BY pd_name";

$result = mysql_query($sql);

$products = array();
while ($row = mysql_fetch_assoc($result)) {
$products[] = $row;
}
?>

And the second one is using our database abstraction. We don't have to initiate the connection this time because it is done from database.php :

<?php
require_once 'config.php';
require_once 'database.php';

$sql = "SELECT *
FROM tbl_product
ORDER BY pd_name";

$result = dbQuery($sql);

$products = array();
while ($row = dbFetchAssoc(&$result)) {
$products[] = $row;
}
?>

As you can see, using database abstraction isn't so hard at all.

Now that we have taken care the database issues we start building the admin pages.