PHP连接错误[关闭]

I am new to PHP, I am trying to implement network communication with mysql database which I made through phpmyadmin over my Bluehost account. Now I have written the following php script to check whether I can connect but I am not able to connect:

          <?php  
          $mysql_host='localhost';
          $mysql_user='xxx';
          $mysql_pass ='xxx';


          mysql_connect ('localhost', '$mysql_user', '$mysql_pass')
          or die ('I cannot connect to the database.');
           //echo 'hello';

          ?>

Try this:

mysql_connect ('localhost', $mysql_user, $mysql_pass)

Instead of:

mysql_connect ('localhost', '$mysql_user', '$mysql_pass')

You do not need single quotes here.

Variables between single quotes are not evaluated

 mysql_connect ('localhost', '$mysql_user', '$mysql_pass')

Try this:

  mysql_connect ('localhost', $mysql_user, $mysql_pass)

the quotes make your vars to a string! and never post you pass and user... even its local use

mysql_connect ( $mysql_host, $mysql_user, $mysql_pass);

dont use die(), use a error log.

better would be a pdo connection, it give you more comfort and securety.

make shure pdo is enadbled in mysql config, mostly it is enabled by default.

you can set up a pdo connection like

$dsn = 'mysql:dbname=<databasename>;host=<hostname>';
  $user = '<user>';
  $password = '<passwd>';

try {                                                                         
    $dbh = new PDO($dsn, $user, $password);
    $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
    $_SESSION['error'] .= 'Verbindung fehlgeschlagen: ' . $e->getMessage();
}     

You have to remove quotes around variables in mysql_connect:

mysql_connect ('localhost', $mysql_user, $mysql_pass)

You should understand diff bet single quotes and double quotes in php. single quotes output string as it is. and double quotes parse string before outputting.