PHP: Database not selected

Question

I'm failing to understand why the function to connect to the database is not working, I have triple checked if there are any mistakes in the variables.

Using mysql_error function on class.php at line 12 I get the following error:

No database selected

class.php

 <?php

class blog {
    private $host;
    private $username;
    private $password;
    private $db;
    private $link;

    public function __construct($host, $username, $password, $db){
    $this->link = mysql_connect($host, $username, $password, $db);
    mysql_select_db($this->db, $this->link) or die (mysql_error());

    }

    function get_content(){
    $sql = "SELECT * FROM content";
    $res = mysql_query($sql);
    while($row = mysql_fetch_assoc($res)){
        echo '<h1>'.$row['title'].'</h1>';
        echo '<p>'.$row['body'].'</p>';
        }
    }
}// End of Class
?>

index.php

  <?php include 'includes/class.php' ?>
<?php


//Setup Connection
$obj = new blog('localhost', 'root', '', 'blog');

//Connect to DB

?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<link rel="stylesheet" type="text/css" href="css/style.css" mce_href="styles1.css">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Mi Blog</title>
</head>

<body>

<div id="page-wrap">
    <?php $obj->get_content() ?>
</div>


</body>
</html>

Christopher Armstrong · Accepted Answer · 2011-08-23 02:03:31Z

10

You're using $this->db but never setting it. Try this:

public function __construct($host, $username, $password, $db){
    $this->db = $db;
    $this->link = mysql_connect($host, $username, $password, $db);
    mysql_select_db($this->db, $this->link) or die (mysql_error());
}

answered Aug 23, 2011 at 2:03

Christopher Armstrong

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Comments

CoolBeans · Accepted Answer · 2011-09-01 22:37:48Z

6

You are failing to set $this->db.

edited Sep 1, 2011 at 22:37

CoolBeans

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answered Aug 23, 2011 at 2:05

nbelmont

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Comments

Book Of Zeus · Accepted Answer · 2011-08-23 02:06:42Z

4

First of all

mysql_select_db($this->db, $this->link) or die (mysql_error());

should be:

mysql_select_db($db, $this->link) or die (mysql_error());

and

$res = mysql_query($sql);

should be

$res = mysql_query($sql, $this->link);

answered Aug 23, 2011 at 2:06

Book Of Zeus

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