How do I work with the class database in any file?

Question

How do I work with the class database in any file?

There is a small class (file: db.php):

spoiler

class Db {

 protected $db;

 public function __construct() {
 $config = require 'config.php';
 $this->db = new PDO('mysql:host='.$config['host'].';charset=utf8;dbname='.$config['name'].", $config['user'], $config['password']);
}

 public function query($sql, $params = []) {
 echo '<pre>' . print_r($sql,true) . '</pre>';
exit;
 $stmt = $this->db->prepare($sql);
 if (!empty($params)) {
 foreach ($params as $key => $val) {
 if (is_int($val)) {
 $type = PDO::PARAM_INT;
 } else {
 $type = PDO::PARAM_STR;
}
 $stmt->bindValue(':'.$key, $val, $type);
}
}
$stmt->execute();
 return $stmt;
}

 public function row($sql, $params = []) {
 $result = $this->query($sql, $params);
 return $result->fetchAll(PDO::FETCH_ASSOC);
}

 public function column($sql, $params = []) {
 $result = $this->query($sql, $params);
 return $result->fetchColumn();
}

 public function lastInsertId() {
 return $this->db->lastInsertId();
}

}

I try to connect in your file (not working):

spoiler

include 'Db.php';

$DB = new Db;

addUser(123, 111111111);

function addUser($user_id, $date) {
 $params = [
 'user_id' => $user_id,
 'date' => $date,
];
 $DB->query('INSERT INTO users (user_id, date) VALUES (:name, :date)', $params);
 return $DB->lastInsertId();
}

Error: Fatal error: Uncaught Error: Call to a member function query() on null

PHP

Albertha90 asked April 19th 20 at 12:36

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More answers about "How do I work with the class database in any file?"

2 answers

Kavon answered on April 19th 20 at 12:40

do require 'Db.php'
and do new Db()

Keon75 answered on · Accepted Answer · 2020-04-19T10:38:43.621Z

The idea is good, but the implementation is not.

To begin with, it is a very inconsistent class.
As they generally use, if the row() function returns more than one row, and all?
In the class a bunch of extra code, but 90% of the functionality of the PDO in it just not available

Class it is necessary to rewrite at least

class Db {
 public $db;

 public function __construct() {
 $config = require __DIR__.'/config.php'; 
 $options = [
 PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
 PDO::ATTR_EMULATE_PREPARES => false,
];
 $dsn = 'mysql:host='.$config['host'].';charset=utf8;dbname='.$config['name'];
 $this->db = new PDO($dsn, $config['user'], $config['password'], $options);
}
 public function query($sql, $params = []) {
 $stmt = $this->db->prepare($sql);
$stmt->execute($params);
 return $stmt;
}
 public function cell($sql, $params = []) {
 return $this->query($sql, $params)->fetchColumn();
}
 public function row($sql, $params = [], $mode=PDO::FETCH_ASSOC) {
 return $this->query($sql, $params)->fetch($mode);
}
 public function all($sql, $params = [], $mode=PDO::FETCH_ASSOC) {
 return $this->query($sql, $params)->fetchAll($mode);
}
 public function column($sql, $params = []) {
 return $this->query($sql, $params)->fetchAll(PDO::FETCH_COLUMN);
}
 public function lastInsertId() {
 return $this->db->lastInsertId();
}
}

after ALL the functionality of PDO is added, it will be possible to make db back private. And to those x then, call it using the missing function body.

And connect the object of this class is a piece of cake: just to bring to the function

include 'Db.php';
$db = new Db;

addUser($db, 123, 111111111);

function addUser($db, $user_id, $date) {
 $params = [
 'user_id' => $user_id,
 'date' => $date,
];
 $db->query('INSERT INTO users (user_id, date) VALUES (:name, :date)', $params);
 return $db->lastInsertId();
}