<?php
$conn = mysql_connect("localhost","tuo_username","tua_password") or die (mysql_error());
$sel = mysql_select_db("nome_tuo_db") or die (mysql_error());
$q="SELECT * FROM tabella WHERE meta_key='first_name' OR meta_key='nick_name'";
$ris=mysql_query($q) or die (mysql_error());
if(mysql_num_rows($ris) > 0){
while($riga=mysql_fetch_array($ris)){
echo $riga['meta_key']." ".$riga['meta_value']."<br />";
}
}else{
echo "record non trovati";
}
?>