Geek asks and answers

PHP OOP MySQL connects

Ok, so I'm a complete newbie to OOP in php, and I thought I would try something easy to get started, but it doesn't work as I would expect

<?php 

class mySQL{

  var $host;
  var $username;
  var $password;
  var $database;

  public function connect($set_host, $set_username, $set_password, $set_database){
    $this->host = $set_host;
    $this->username = $set_username;
    $this->password = $set_password;
    $this->database = $set_database;

    mysql_connect("$host", "$username", "$password")or die("cannot connect");
    mysql_select_db("$database")or die("cannot select DB");

  }

}

$connect = new mySQL();
$connect -> connect('localhost', 'user', 'pass', 'database1');

$settings_query = mysql_query("SELECT * FROM settings");
$settings = mysql_fetch_array($settings_query);

echo $settings['title']; 

?>

All I get is "Unable to Connect" on my page.

+3
source share
6 answers

In your connection method, you are trying to use the following variables:

  • $host
  • $username
  • $password
  • $database

which will be local to your method connect().
But these variables do not exist.


Instead, if you want to use the properties $host , $usernameand $passwordthat are defined in your class, you should use $thisto access them :

  • $this->host
  • $this->username
  • $this->password
  • $this->database

PHP - .

+6
mysql_connect("$host", "$username", "$password")or die("cannot connect");

$host . mysql_connect( $this->host, $this->username, $this->password ); .

, , mysql?

+1
class mySQL{

  var $host;
  var $username;
  var $password;
  var $database;
  public $dbh;  //Variable for storing connection

  public function connect($set_host, $set_username, $set_password, $set_database){
    $this->host = $set_host;
    $this->username = $set_username;
    $this->password = $set_password;
    $this->database = $set_database;

    $this->dbh = mysql_connect($this->host, $this->username, $this->password)or die("cannot connect"); //Store data connection specifier in object
    mysql_select_db($this->database)or die("cannot select DB");

  }

  public function query($sql)
  {
       return mysql_query($sql,$this->dbh);  //Specify connection handler when doing query
  }

  public function fetch($sql)
  {
       return mysql_fetch_array($this->query($sql));
  }

}
$connect = new mySQL();
$connect->connect('localhost', 'user', 'pass', 'database1');
$settings_query = mysql_query("SELECT * FROM settings", $connect->dbh); //Specify connection handler when doing query
$settings = mysql_fetch_array($settings_query);

//With query method in object you can do this:    
$settings_query = $connect->query("SELECT * FROM settings");  //Use object method to query
$settings = mysql_fetch_array($settings_query);

//with fetch method in object you can just do this:
$settings = $connect->fetch("SELECT * FROM settings");

echo $settings['title'];

, , , :

$connect1 = new MySQL();
$connect2 = new MySQL();
$connect1->connect('localhost','user','pass','database1');
$connect2->connect('localhost','user','pass','database2');

/ sql , .

, , ($this->var).

+1

mysql_connect( $this->host,  $this->username, $this->password)or die("cannot connect");
0

, $this:

mysql_connect("{$this->host}", "{$this->username}", "{$this->password}")or die("cannot connect");
mysql_select_db("{$this->database}")or die("cannot select DB");
0
class mySQL{

  public function connect($set_host, $set_username, $set_password, $set_database){

    mysql_connect("$set_host", "$set_username", "$set_password")or die("cannot connect");
    mysql_select_db("$set_database")or die("cannot select DB");

  }

}

, , .

0

More articles:


All Articles