I've been trying to convert my application from using the depreciated mysql syntax to PDO for connecting to the database and performing queries, and it's been a pain so far.
Right now I have a class, db_functions.php, in which I'm trying to create a PDO connection to the database, as well as perform all the CRUD operations inside of.
Here is a sampling of the code:
db_functions.php
<?php
class DB_Functions {
private $db;
// constructor
function __construct() {
require_once 'config.php';
// connecting to mysql
try {
$this->$db = new PDO('mysql:host=localhost;dbname=gcm', DB_USER, DB_PASSWORD);
}
catch (PDOException $e) {
$output = 'Unable to connect to database server.' .
$e->getMessage();
exit();
}
}
// destructor
function __destruct() {
}
public function getAllUsers() {
try {
$sql = "select * FROM gcm_users";
//$result = mysql_query("select * FROM gcm_users");
$result = $this->$db->query($sql);
return $result;
}
catch (PDOException $e) {
$error = 'Error getting all users: ' . $e->getMessage();
}
}
With that code, i'm getting the following error:
Notice: Undefined variable: db in C:\xampp\htdocs\gcm\db_functions.php on line 12
Fatal error: Cannot access empty property in C:\xampp\htdocs\gcm\db_functions.php on line 12
Line 12 is:
$this->$db = new PDO('mysql:host=localhost;dbname=gcm', DB_USER, DB_PASSWORD);
How could I fix this so that I have a proper instance of a PDO connection to my database that I can use to create queries in other methods in db_functions, such as getAllUsers()
I used the answer found at How do I create a connection class with dependency injection and interfaces? to no avail.
TYPO
//$this->$db =
$this->db =
same here
//$this->$db->query($sql);
$this->db->query($sql);
and i also would use 127.0.0.1 instead of localhost to improve the performance otherwise making a connection will take very long... a couple of seconds just for connection...
Related
I have a project folder name utilities.
The list of directory is:
- utilities
- tli
- database
Connection.php
index.php
The Connection.php is PDOConnection.
The code is:
<?php
namespace app\tli\database;
use PDO;
use PDOException;
Class Connection
{
private $server = "mysql:host=localhost;dbname=ytsurumaru_hanwa_coil_v.2";
private $user = "root";
private $pass = "";
private $options = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,);
protected $con;
public function openConnection()
{
try {
$this->con = new PDO($this->server, $this->user, $this->pass, $this->options);
return $this->con;
} catch (PDOException $e) {
return "There is some problem in connection: " . $e->getMessage();
}
}
public function closeConnection()
{
$this->con = null;
}
}
UPDATED SOURCE
Now, I need this Connection instance in index.php
<?php
namespace app;
use app\tli\database\Connection;
use PDOException as PDOEx;
require('tli/database/Connection.php');
try {
$connection = new Connection(); // not found
$connection->openConnection();
} catch (PDOEx $e) {
echo $e->getMessage();
}
When I run it,
D:\wamp64\www\utilities\tli>php index.php
Warning: require(tli/database/Connection.php): failed to open stream: No such file or directory in D:\wamp64\www\utilities\tli\index.php on line 8
Fatal error: require(): Failed opening required 'tli/database/Connection.php' (include_path='.;C:\php\pear') in D:\wamp64\www\utilities\tli\index.php on line 8
How to solved this, is my namepace have a problem ?
Isn't this enough to access your database connection?
require 'tli/database/Connection.php';
Then, since you are in a different name space and you are not aliasing, in your 'try catch block' you should instead of:
$connection = new Connection(); // not found
Do something like:
$connection = new \tli\database\Connection();
Make sure to set your paths right.
OR
You can alias to a different name like so:
namespace app;
require 'tli/database/Connection.php';
use tli\database\Connection as MyConnection;
$connection = new MyConnection();
You need to use one of these:
include('tli/database/Connection.php')
include_once('tli/database/Connection.php')
require('tli/database/Connection.php')
require_once('tli/database/Connection.php')
or if you want some more automation use autoloader.
You may want to look at this SO question and all the linked things.
This question already has answers here:
pdo - Call to a member function prepare() on a non-object [duplicate]
(8 answers)
Closed 6 years ago.
I'm writing a function to check for records in my database before executing anything, and i'm getting the error Call to a member function prepare() which i don't quite understand. I've been struggeling for quite some time now, and i'd really appriciate some help
The problem should be with the prepare() in line 19
<?php
$dsn = "xxx"; // Database Source Name
$username="xxx"; // User with acress to database. Root is MySQL admin.
$password="xxx"; //The user password.
try {
$conn = new PDO($dsn, $username, $password);
$conn ->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch(PDOException $e) {
echo "Connection failed: ".$e->getMessage();
}
//------------------------ Does the category already exist? -------------------------
function checkuser($fbid,$fbfname,$fblname,$femail) {
$sql="SELECT COUNT(*) AS subjectcount FROM Users WHERE Fuid=:Fuid";
try {
$stmt = $conn->prepare($sql);
$stmt->bindValue(":Fuid",$_SESSION['FBID'], PDO::PARAM_INT);
$stmt->execute();
$row = $stmt->fetch(PDO::FETCH_ASSOC);
$subjectcount=$row["subjectcount"];
} catch (PDOException $e) {
echo "Server Error - try again!".$e->getMessage();
}
//------------------------ If it dosn't, insert it -------------------------
if ($subjectcount==0) {
And i'm having a hard time debugging since i dont quite understand the cause of this error.
I updated my code to
<?php
$dsn = "xxx"; // Database Source Name
$username="xxx"; // User with acress to database. Root is MySQL admin.
$password="xxx"; //The user password.
try {
$conn = new PDO($dsn, $username, $password);
$conn ->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch(PDOException $e) {
echo "Connection failed: ".$e->getMessage();
}
//------------------------ Does the category already exist? -------------------------
function checkuser($fbid,$fbfname,$fblname,$femail) {
global $conn;
$sql="SELECT COUNT(*) AS subjectcount FROM Users WHERE Fuid=:Fuid";
try {
$stmt = $conn->prepare($sql);
$stmt->bindValue(":Fuid",$_SESSION['FBID'], PDO::PARAM_INT);
$stmt->execute();
$row = $stmt->fetch(PDO::FETCH_ASSOC);
$subjectcount=$row["subjectcount"];
} catch (PDOException $e) {
echo "Server Error - try again!".$e->getMessage();
exit;
}
//------------------------ If it dosn't, insert it -------------------------
if ($subjectcount==0) {
I guess the full error message is:
Fatal error: Call to a member function prepare() on a non-object
Right?
You are calling the member function (= function which is a member of a class instance) prepare of the variable $conn which is not declared in the scope of your checkuser function, it's declared outside (in global scope)!
To "import" it into your function so you can access it, put this line at the top of your function:
global $conn;
Also, it looks like you don't have full error reporting enabled, otherwise you would have seen this error before the fatal one, giving you another clue:
Notice: Undefined variable: conn
(By the way, you should exit; after outputing the DB error message in your catch block - otherwise you will print the error but continue to the rest, with a nonexisting DB connection!)
I need to do continuous parsing of several external stomp data streams, inserts of relevant fields into a MySql db, and regular queries from the db. All of this is in a protected environment - ie I'm not dealing with web forms or user inputs
Because I'm implementing a range of inserts into + queries from different tables, I've decided to set up a PDO active record model - following the advice of Nicholas Huot and many SO contributors.
I've got a simple repeated insert working OK, but after several days of grief can't get a prepared insert to fly. I want to use prepared inserts given there are going to be a lot of these (ie for performance).
Relevant bits of the code are :
=========
Database class :
private function __construct()
{
try {
// Some extra bad whitespace removed around =
$this->dbo = new PDO('mysql:host=' . DBHOST . ';dbname=' . DBNAME, DBUSER, DBPSW, $options);
} catch (PDOException $e) {
echo 'Connection failed: ' . $e->getMessage();
}
}
public static function getInstance()
{
if(!self::$instance)
{
self::$instance = new self();
}
return self::$instance;
}
public function prepQuery($sql) // prepared statements
{
try {
$dbo = database::getInstance();
$stmt = new PDOStatement();
$dbo->stmt = $this->$dbo->prepare($sql);
var_dump($dbo);
}
catch (PDOException $e) {
echo "PDO prepare failed : ".$e->getMessage();
}
}
public function execQuery($sql) // nb uses PDO execute
{
try {
$this->results = $this->dbo->execute($sql);
}
catch (PDOException $e) {
echo "PDO prepared Execute failed : \n";
var_dump(PDOException);
}
}
=========
Table class :
function storeprep() // prepares write to db. NB prep returns PDOstatement
{
$dbo = database::getInstance();
$sql = $this->buildQuery('storeprep');
$dbo->prepQuery($sql);
return $sql;
}
function storexecute($paramstring) // finalises write to db :
{
echo "\nExecuting with string : " . $paramstring . "\n";
$dbo = database::getInstance(); // Second getInstance needed ?
$dbo->execQuery(array($paramstring));
}
//table class also includes buildQuery function which returns $sql string - tested ok
=======
Controller :
$dbo = database::getInstance();
$movements = new trainmovts();
$stmt = $movements->storeprep(); // set up prepared query
After these initial steps, the Controller runs through a continuous loop, selects the fields needed for storage into a parameter array $exec, then calls $movements->storexecute($exec);
My immediate problem is that I get the error message "Catchable fatal error: Object of class database could not be converted to string " at the Database prepquery function (which is called by the Table storeprep fn)
Can anyone advise on this immediate prob, whether the subsequent repeated executes should work in this way, and more widely should I change anything with the structure ?
I think your problem in this line $dbo->stmt = $this->$dbo->prepare($sql);, php want to translate $dbo to string and call function with this name from this. Actually you need to use $this->dbo.
And actually your functions not static, so i think you don't need to call getInstance each time, you can use $this.
Hi i am trying to move from MySQL to MySQLi in my PHP script, i had this system class with the function that connects to the database that i call whenever i need, with a simple method like this:
Sys::database_connect();
the actual code of the function is:
function database_connect(){
require 'conf.php';//configuration file with database variables (sql_)
mysql_connect($sql_serv, $sql_user, $sql_pw) OR die('ERRO!!! não ligou a base de dados');
mysql_select_db($sql_bd);
}
after calling the function i can query the database without problem.
But I cant do the same with mysqli if I put this in the sys class:
function database_connect(){
require 'conf.php';
$mysqli = new mysqli($sql_serv, $sql_user, $sql_pw, $sql_bd);
if (mysqli_connect_errno()) {
printf("Ligação à Base de dados falhou: %s\n", mysqli_connect_error());
exit();
}
}
When I call
Sys::database_connect();
it connects to the database but i can't query has i used to what i would like would be a simple method as I have done with normal MySQL, if somebody can explain what am I doing wrong or why exactly I cannot do it like that...
Thank you in advance;
Fernando Andrade.
Your later queries have to use the mysqli connection identifier, you create when connecting to the database. So save this to a property of your system class and use it later on.
function database_connect(){
require 'conf.php';
$mysqli = new mysqli($sql_serv, $sql_user, $sql_pw, $sql_bd);
if (mysqli_connect_errno()) {
printf("Ligação à Base de dados falhou: %s\n", mysqli_connect_error());
exit();
}
Sys::$dbConn = $mysqli;
}
and then later on
function query( $sql ) {
Sys::$dbConn->query( $sql );
// error handling etc.
}
I wrote an extend for the mysqli database class
class database extends mysqli {
function __construct() {
parent::__construct('host', 'user', 'password', 'database');
if(mysqli_connect_error()) {
die('Connect error ('.mysqli_connect_errno().')'.mysqli_connect_error());
}
parent::query("SET NAMES 'utf8'");
}
function query($query) {
$result = parent::query($query);
if(!$result) {
echo "<strong>MySQL error</strong>: ".$this->error."<br />QUERY: ".$query;
die();
}
if(!is_object($result)) {
$result = new mysqli_result($this);
}
return $result;
}
}
So connecting to database is $db = new database()
Executing a query is $db->query(YOUR QUERY);
I have a script that does a lot of legwork nightly.
It uses a PDO prepared statement that executes in a loop.
The first few are running fine, but then I get to a point where they all fail with the error:
"MySQL server has gone away".
We run MySQL 5.0.77.
PHP Version 5.2.12
The rest of the site runs fine.
Most likely you sent a packet to the server that is longer than the maximum allowed packet.
When you try to insert a BLOB that exceeds your server's maximum packet size, even on a local server you will see the following error message on clientside:
MySQL server has gone away
And the following error message in the server log: (if error logging is enabled)
Error 1153 Got a packet bigger than 'max_allowed_packet' bytes
To fix this, you need to decide what is the size of the largest BLOB that you will ever insert, and set max_allowed_packet in my.ini accordingly, for example:
[mysqld]
...
max_allowed_packet = 200M
...
The B.5.2.9. MySQL server has gone away section of the MySQL manual has a list of possible causes for this error.
Maybe you are in one of those situations ? -- Especially considering you are running a long operation, the point about wait_timeout might be interesting...
I had the same problem where the hosting server administration kills connection if there is a timeout.
Since I have used the query in major part I wrote a code which instead of using PDO class we can include the below class and replace the classname to "ConnectionManagerPDO". I just wrapped the PDO class.
final class ConnectionManagerPDO
{
private $dsn;
private $username;
private $passwd;
private $options;
private $db;
private $shouldReconnect;
const RETRY_ATTEMPTS = 3;
public function __construct($dsn, $username, $passwd, $options = array())
{
$this->dsn = $dsn;
$this->username = $username;
$this->passwd = $passwd;
$this->options = $options;
$this->shouldReconnect = true;
try {
$this->connect();
} catch (PDOException $e) {
throw $e;
}
}
/**
* #param $method
* #param $args
* #return mixed
* #throws Exception
* #throws PDOException
*/
public function __call($method, $args)
{
$has_gone_away = false;
$retry_attempt = 0;
try_again:
try {
if (is_callable(array($this->db, $method))) {
return call_user_func_array(array($this->db, $method), $args);
} else {
trigger_error("Call to undefined method '{$method}'");
/*
* or
*
* throw new Exception("Call to undefined method.");
*
*/
}
} catch (\PDOException $e) {
$exception_message = $e->getMessage();
if (
($this->shouldReconnect)
&& strpos($exception_message, 'server has gone away') !== false
&& $retry_attempt <= self::RETRY_ATTEMPTS
) {
$has_gone_away = true;
} else {
/*
* What are you going to do with it... Throw it back.. FIRE IN THE HOLE
*/
throw $e;
}
}
if ($has_gone_away) {
$retry_attempt++;
$this->reconnect();
goto try_again;
}
}
/**
* Connects to DB
*/
private function connect()
{
$this->db = new PDO($this->dsn, $this->username, $this->passwd, $this->options);
/*
* I am manually setting to catch error as exception so that the connection lost can be handled.
*/
$this->db->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
}
/**
* Reconnects to DB
*/
private function reconnect()
{
$this->db = null;
$this->connect();
}
}
Then use can start using the above class as you do in PDO.
try {
$db = new ConnectionManagerPDO("mysql:host=localhost;dbname=dummy_test", "root", "");
$query = $db->query("select * from test");
$query->setFetchMode(PDO::FETCH_ASSOC);
}
catch(PDOException $e){
/*
handle the exception throw in ConnectionManagerPDO
*/
}
Try using PDO::setAttribute(PDO::ATTR_EMULATE_PREPARES, true) on your pod instance(s). Dont know that it will help but with no log data its all i got.
It's likely that either your connection has been killed (e.g. by wait_timeout or another thread issuing a KILL command), the server has crashed or you've violated the mysql protocol in some way.
The latter is likely to be a bug in PDO, which is extremely likely if you're using server-side prepared statements or multi-results (hint: Don't)
A server crash will need to be investigated; look at the server logs.
If you still don't know what's going on, use a network packet dumper (e.g. tcpdump) to dump out the contents of the connection.
You can also enable the general query log - but do it very carefully in production.
Nathan H, below is php class for pdo reconnection + code usage sample.
Screenshot is attached.
<?php
# set errors reporting level
error_reporting(E_ALL ^ E_NOTICE ^ E_WARNING);
# set pdo connection
include('db.connection.pdo.php');
/* # this is "db.connection.pdo.php" content
define('DB_HOST', 'localhost');
define('DB_NAME', '');
define('DB_USER', '');
define('DB_PWD', '');
define('DB_PREFIX', '');
define('DB_SHOW_ERRORS', 1);
# connect to db
try {
$dbh = new PDO('mysql:host='.DB_HOST.';dbname='.DB_NAME, DB_USER, DB_PWD);
$dbh->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
$dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, TRUE);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch(PDOException $e) {
# echo $e->getMessage()."<br />";
# exit;
exit("Site is temporary unavailable."); #
}
*/
$reconnection = new PDOReconnection($dbh);
$reconnection->getTimeout();
echo $dbh->query('select 1')->fetchColumn();
echo PHP_EOL;
echo 'sleep 10 seconds..'.PHP_EOL;
sleep(10);
$dbh = $reconnection->checkConnection();
echo $dbh->query('select 1')->fetchColumn();
echo PHP_EOL;
echo 'sleep 35 seconds..'.PHP_EOL;
sleep(35);
$dbh = $reconnection->checkConnection();
echo $dbh->query('select 1')->fetchColumn();
echo PHP_EOL;
echo 'sleep 55 seconds..'.PHP_EOL;
sleep(55);
$dbh = $reconnection->checkConnection();
echo $dbh->query('select 1')->fetchColumn();
echo PHP_EOL;
echo 'sleep 300 seconds..'.PHP_EOL;
sleep(300);
$dbh = $reconnection->checkConnection();
echo $dbh->query('select 1')->fetchColumn();
echo PHP_EOL;
# *************************************************************************************************
# Class for PDO reconnection
class PDOReconnection
{
private $dbh;
# constructor
public function __construct($dbh)
{
$this->dbh = $dbh;
}
# *************************************************************************************************
# get mysql variable "wait_timeout" value
public function getTimeout()
{
$timeout = $this->dbh->query('show variables like "wait_timeout"')->fetch(); # print_r($timeout);
echo '========================'.PHP_EOL.'mysql variable "wait_timeout": '.$timeout['Value'].' seconds.'.PHP_EOL.'========================'.PHP_EOL;
}
# *************************************************************************************************
# check mysql connection
public function checkConnection()
{
try {
$this->dbh->query('select 1')->fetchColumn();
echo 'old connection works..'.PHP_EOL.'========================'.PHP_EOL;
} catch (PDOException $Exception) {
# echo 'there is no connection.'.PHP_EOL;
$this->dbh = $this->reconnect();
echo 'connection was lost, reconnect..'.PHP_EOL.'========================'.PHP_EOL;
}
return $this->dbh;
}
# *************************************************************************************************
# reconnect to mysql
public function reconnect()
{
$dbh = new PDO('mysql:host=' . DB_HOST . ';dbname=' . DB_NAME, DB_USER, DB_PWD);
$dbh->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
$dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, TRUE);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
return $dbh;
}
}
# /Class for PDO reconnection
# *************************************************************************************************
I got this same error this morning after changing my DB properties in Laravel. I'd commented out the old settings and pasted in new ones. The problem was that the new settings where missing the DB_CONNECTION variable:
DB_CONNECTION=pgsql
Obviously you need to add whatever connection type you are using: sqlite, mysql, ...
I had the exact same problem.
I resolved this issue by doing unset on the PDO object instead of seting it to NULL.
For example:
function connectdb($dsn,$username,$password,$driver_options) {
try {
$dbh = new PDO($dsn,$username,$password,$driver_options);
return $dbh;
}
catch(PDOException $e)
{
print "DB Error: ".$e->getMessage()."<br />";
die();
}
}
function closedb(&$dbh) {
unset($dbh); // use this line instead of $dbh = NULL;
}
Also, it is highly recommended to unset all your PDO objects. That includes variables that contain prepared statements.
$pdo = new PDO(
$dsn,
$config['username'],
$config['password'],
array(
PDO::ATTR_PERSISTENT => true,
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
)
);
try this. It may work