不能使用DB(尝试设置active active mySQL数据库) - Can't use DB (trying to set active active mySQL database)

Can't use DB (trying to set active active mySQL database)

  // Set the active mySQL database
$db_selected = mysql_select_db($dbname, $db);
if (!$db_selected) {
die ("Can''t use db : " . mysql_error());
}

错误:警告:mysql_select_db():所提供的参数不是一个有效的MySQL-Link资源在/home/content/41/10663841/html/storelocator/phpsqlsearch_genxml.php第21行不能使用db:

我猜，你必须先连接到MySQL:

// connect to mysql
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link) {
    die('cannot connect, error: ' . mysql_error());
}
// select db "xyz"
$db_selected = mysql_select_db('xyz', $link);
if (!$db_selected) {
    die ('cannot select DB, error: ' . mysql_error());
}

注意:对于你未来的代码，我建议使用PDO: http://php.net/manual/en/pdo.connections.php