Please let me know if any improvements could be made to my PHP PDO MySQL Class.
<?php
/**
*
* Database.
*
* Version 1.2 (March 2017).
*
**/
class Database {
// Connection information.
private $connection;
// SQL querey information.
private $querey;
// Connected to the database server.
private $connected = false;
// Errors.
private $error;
// Hostname or IP address of the database server.
private $host = "127.0.0.1";
// Port to access the database server.
private $port = 3306;
// Name of the database.
private $database = "test";
// Username.
private $username = "test";
// Password.
private $password = "qgmxnMVroz9PHTY36Eq4qwpA5GSXwFyb"; // This is a random password!
// Database charset.
private $charset = "UTF8";
// PDO options.
private $options = [
PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
PDO::ATTR_EMULATE_PREPARES => false,
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_PERSISTENT => true
];
/**
*
* Constructor.
*
* Creates connection to the database server.
*
**/
public function __construct() {
if ($this->connected === true) {
return true;
} else {
try {
$this->connection = new PDO("mysql:host={$this->host};port={$this->port};dbname={$this->database};charset={$this->charset}", $this->username, $this->password, $this->options);
$this->connected = true;
} catch (PDOException $e) {
$this->error = $e->getMessage();
return null;
}
}
}
/**
*
* Query the Database.
*
* Used for SELECT, INSERT, UPDATE and DELETE statements.
*
**/
public function query($query, $parameters = [], $expectSingleResult = false) {
if ($this->connected === true) {
if (is_string($query) && $query !== "" && is_array($parameters) && is_bool($expectSingleResult)) {
try {
// Prepare SQL querey.
$this->querey = $this->connection->prepare($query);
// Bind parameters to SQL querey.
foreach ($parameters as $placeholder => $value) {
// Parameter type.
if (is_string($value)) {
// Parameter is a string.
$type = PDO::PARAM_STR;
} elseif (is_int($value)) {
// Parameter is a integer.
$type = PDO::PARAM_INT;
} elseif (is_bool($value)) {
// Parameter is a boolean.
$type = PDO::PARAM_BOOL;
} else {
// Parameter is NULL.
$type = PDO::PARAM_NULL;
}
// Bind parameter.
$this->querey->bindValue($placeholder, $value, $type);
}
// Execute SQL querey.
$this->querey->execute();
// Get Result of SQL querey.
if ($expectSingleResult === true) {
$results = $this->querey->fetch();
} else {
$results = $this->querey->fetchAll();
}
// Return results of SQL querey.
return $results;
} catch (PDOException $e) {
$this->error = $e->getMessage();
}
} else {
$this->error = "Invalid Querey or Paramaters";
return null;
}
} else {
$this->error = "Not Connected to Database Server";
return null;
}
}
/**
*
* Row count for the last querey.
*
**/
public function rowCount() {
if ($this->connected === true) {
return $this->querey->rowCount();
} else {
$this->error = "Not Connected to Database Server";
return null;
}
}
/**
*
* Get ID for the last querey.
*
**/
public function lastId() {
if ($this->connected === true) {
return $this->connection->lastInsertId();
} else {
$this->error = "Not Connected to Database Server";
return null;
}
}
/**
*
* Begin a transaction.
*
**/
public function beginTransaction() {
if ($this->connected === true) {
return $this->connection->beginTransaction();
} else {
$this->error = "Not Connected to Database Server";
return null;
}
}
/**
*
* Rollback and cancel/end a transaction.
*
**/
public function cancelTransaction() {
if ($this->connected === true) {
return $this->connection->rollBack();
} else {
$this->error = "Not Connected to Database Server";
return null;
}
}
/**
*
* Or...
*
**/
public function rollbackTransaction() {
if ($this->connected === true) {
return $this->connection->rollBack();
} else {
$this->error = "Not Connected to Database Server";
return null;
}
}
/**
*
* Commit and end a transaction.
*
**/
public function endTransaction() {
if ($this->connected === true) {
return $this->connection->commit();
} else {
$this->error = "Not Connected to Database Server";
return null;
}
}
/**
*
* Close the current connection the the database server.
*
**/
public function close() {
$this->connection = null;
}
}
?>
