Примерно так:
$sql =mysql_query ("SELECT 'text' FROM 'biznes' WHERE 'text'='text')";
if(mysql_num_rows($sql) < 0)
{
mysql_query("INSERT INTO `biznes`(foto,text) VALUES ('/images/$imge','$x')");
}else {
mysql_query("INSERT INTO `biznes`(reklama) VALUES ('1')");
}