mysql - Can't get PHP PDO and OOP classes to work -

i trying learn how use php pdo object oriented programming.

i have tried following these 2 tutorials: http://culttt.com/2012/10/01/roll-your-own-pdo-php-class/ http://culttt.com/2012/09/24/prevent-php-sql-injection-with-pdo-prepared-statements/

but can't on either of them work.

the second 1 gives download link pre-written wrapper class class.db.php http://www.imavex.com/php-pdo-wrapper-class/

using pre-written wrapper class , trying simple tutorial.php (credentials changed):

// include database class include("class.db.php");  // connect database $db = new db("mysql:host=localhost;dbname=my-db-name", "my-username", "my-password");  $results = $db->select("ad_publication"); print_r($results); 

the above shows blank page.

i know there nothing wrong pre-written class , text of above example copied directly out of tutorial , comments full of , praise.

i know there nothign wrong credentials works fine:

try {     $pdo = new pdo('mysql:host=localhost;dbname=my-db-name', 'my-username', 'my-password');      $pdo->setattribute(pdo::attr_errmode, pdo::errmode_exception);     $pdo->exec('set names "utf8"');      $output = 'connection successful';     echo $output;     }     catch (pdoexception $e)     {     $output = 'unable connect database server.' . $e->getmessage();     echo $output;     exit();     } 

and outputs connection successful

my server running php 5.5 , table used in example above innodb table.

when run example select statement error logs show:

php notice: undefined variable: ghg678 in /var/www/vhosts/mywebsite.com.au/httpdocs/booking/tutorial.php on line 7

line 7:

$db = new db("mysql:host=localhost;dbname=my-db-name", "my-username", "my-password"); 

php warning: creating default object empty value in /var/www/vhosts/mywebsite.com.au/httpdocs/booking/class.db.php on line 18

line 18:

$this->error = $e->getmessage(); // (from public function __construct)` 

php fatal error: call member function select() on non-object in /var/www/vhosts/mywebsite.com.au/httpdocs/booking/tutorial.php on line 9

line 9:

$results = $db->select("ad_publication"); // (an existing table data in it) 

i can't see doing wrong wrapper class not written me , no-one else complaining (heaps of praise) , contents of tutorial.php copied directly page table name changed.

like say, using pdo connection , doing normal pdo queries without wrapper class, work fine.

can here see going wrong or know of should at?

i'm not sure why copped -1 question?? thought complete.

anyway, @sean providing clue answer.

my password in fact have $ character in it.

the connection code of mine work (as shown above) is:

$pdo = new pdo('mysql:host=localhost;dbname=my-db-name', 'my-username', 'my-password'); 

their code using is:

$pdo = new pdo("mysql:host=localhost;dbname=my-db-name", "my-username", "my-password"); 

changing " characters ' worked straight away. password auto-generated hosts (plesk) , don't know enough php know there difference between ' , ". i've never known why people use 1 , use other. seems still have lot learn.

@sean, because didn't put reply, couldn't choose suggestions answer, don't know how give points, thank steering me in right direction.