On pages that get information from the database you will have a recordset. It probably looks something like this: (keep in mind where I have "recordset" yours may say something else. Same with "yourdatabase".
mysql_select_db($database_yourdatabase, $yourdatabase);
$query_recordset = "SELECT * FROM customer";
$recordset = mysql_query($query_recordset, $yourdatabase) or die(mysql_error());
$row_recordset = mysql_fetch_assoc($recordset);
$totalRows_recordset = mysql_num_rows($recordset);
The query above will get all the columns from the customer table. To display the information you would have a repeating region that shows all the customers. It may look something like:
<table>
<?php do { ?>
<tr><td>
<?php echo $row_recordset['customerName']; ?>
</td></tr>
<?php } while ($row_recordset = mysql_fetch_assoc($recordset)); ?>
</table>
If you wanted to pull data from both the customer and pet tables using one recordset instead of two, you would replace:
"SELECT * FROM customer";
With the one I posted earlier:
"SELECT * FROM customer INNER JOIN pet ON (customer.customerID = pet.customerID)"
Then you could have a repeat region like:
<table>
<?php do { ?>
<tr><td>
<?php echo "Customer name: ".$row_recordset['customerName']."<br/>Pet name: ".$row_recordset['petName']; ?>
</td></tr>
<?php } while ($row_recordset = mysql_fetch_assoc($recordset)); ?>
</table>