If, for whatever reason, there is an error in creation of an entry using the mapper I get an error.
I'd like to do a custom notification and fail gracefully like so...
try {
$request->save();
} catch (Exception $e) {
$this->utils->errorNotify($f3,'could not create a request entry',http_build_query($_POST));
return null;
}
is this possible with F3?
\DB\SQL is a subclass of PDO so it can throw catchable PDO exceptions. Since these are disabled by default, you need to enable them first. This can be done in 2 different ways:
at instantiation time, for all transactions:
$db = new \DB\SQL($dsn, $user, $pwd, array( \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION ));
later on in the code, on a per-transaction basis:
$db->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
Once PDO exceptions are enabled, just catch them as other exceptions:
try {
$db->exec('INSERT INTO mytable(id) VALUES(?)','duplicate_id');
} catch(\PDOException $e) {
$err=$e->errorInfo;
//$err[0] contains the error code (23000)
//$err[2] contains the driver specific error message (PRIMARY KEY must be unique)
}
This also works with DB mappers, since they rely on the same DB\SQL class:
$db=new \DB\SQL($dsn,$user,$pwd,array(\PDO::ATTR_ERRMODE=>\PDO::ERRMODE_EXCEPTION));
$mytable=new \DB\SQL\Mapper($db,'mytable');
try {
$mytable->id='duplicate_id';
$mytable->save();//this will throw an exception
} catch(\PDOException $e) {
$err=$e->errorInfo;
echo $err[2];//PRIMARY KEY must be unique
}
Related
What is the proper way to handle error on duplicate entries for PHP/MySQL?
The code below is not working even tho the code 1062 is the right code for duplicate entries. Should i use DBO instead here? Unfortunately i'm not familiar yet.
<?php
try {
mysql_query('INSERT INTO TP2_ORGANISME VALUES (A0A0, Equiterre, 1,
/photos/equiterre_logo.png, Steve Guilbault, steve#equiterre.org');
} catch {
if (mysql_errno() == 1062)
echo 'Duplicate key entry';
}
?>
I'm just looking for a simple try catch or anything that can just let me print a message to the user who entered a duplicate that he has to enter another value for the primary key.
thanks
mysql_query() does not throw exceptions (and only exceptions can be caught). mysqli_ and PDO can, if you enable it to. mysql_ is also very obsolete (and has been for many years already), so use PDO or MySQLi with exception-mode enabled, and it'll work. Both these APIs support prepared statements, so you should use that too if you start inputting variables in your query.
For MySQLi, you need mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); before the connection, and for PDO you need $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
MySQLi example
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli($hostname, $username, $password, $databasename);
$mysqli->set_charset("utf8");
try {
$mysqli->query("INSERT INTO TP2_ORGANISME
VALUES ('A0A0', 'Equiterre', 1, '/photos/equiterre_logo.png', 'Steve Guilbault', 'steve#equiterre.org')");
} catch (mysqli_sql_exception $e) {
if ($e->getCode() == 1062) {
// Duplicate user
} else {
throw $e;// in case it's any other error
}
}
PDO example
$pdo = new PDO("mysql:host=$hostname;dbname=$databasename;charset=utf8", $username, $password);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); // Enables exception mode
try {
$pdo->query("INSERT INTO TP2_ORGANISME
VALUES ('A0A0', 'Equiterre', 1, '/photos/equiterre_logo.png', 'Steve Guilbault', 'steve#equiterre.org')");
} catch (PDOException $e) {
if ($e->getCode() == 1062) {
// Duplicate user
} else {
throw $e;// in case it's any other error
}
}
MySQLi exception class and mysqli_report()
PDO exception class and PDO::setAttribute()
When you start introducing variables into your queries, look into using a prepared statement (How can I prevent SQL injection in PHP?).
I found this block of code really helped capture the 1062 error, and then redirect from the signup page to the login page, if the error happened. Tested it, and it all works.
catch (PDOException $e) {
if(str_contains($e, '1062 Duplicate entry')) {
header("Location: login.php");
}
die("Error inserting user details into database: " . $e->getMessage());
}
Hi I have the following code :
try {
$sth = $this->container->db->prepare("select x from table");
$sth->execute();
$result = $sth->fetchAll(PDO::FETCH_ASSOC);
return $result;
} catch (\PDOException $e) {
throw new ServerException("Could not get data");
} catch (\Exception $e) {
return false;
}
using slim 3 with wamp
the problem is when I point to the API(polling every 1 second) I got the following error:
Fatal error: Call to a member function prepare() on boolean in /
2 issues : it throws an error to the client
and it throws an error in php_error.log under wamp and the file becomes bigger
how can I prevent and catch those errors
PDO class:
public function getConnection($dsn, $username, $password) {
$conn = null;
try {
$conn = new PDO($dsn, $username, $password);
//Set common attributes
$conn->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
return $conn;
} catch (PDOException $e) {
return false;
//TODO: flag to disable errors?
throw $e;
}
catch(Exception $e) {
die();
//TODO: flag to disable errors?
throw $e;
}
}
Like many learners, you are taking this matter upside down
You should never actually catch an exception like this.
it throws an error to the client
Disable it for the whole site on the live server. There should be not a single PHP error message shown to the user, no matter if it's PHP exception or a filesystem error. Set display_errors to a negative value and forget this matter for all.
how can I prevent and catch those errors
Again, you should never do anything like this, bluntly catching every error and just dismissing it. It's like using the notorious # operator
it throws an error in php_error.log under wamp and the file becomes bigger
Ok, only this one makes sense. There are two possible solutions:
The best one: configure your mysql server properly so it wouldn't die under such a light load like 1 RPS.
Okay, what you actually want but I still don't recommend as it never pays to sweep the dirt under the rug: catch the exception, then verify if it's one you expect, then do something (i.e. try to reconnect after a short timeout), but re-throw the exception otherwise so you will have an idea when something else would go wrong. For this purpose you should add a condition in the try..catch block that should verify the error, handle it if it's one that you expect or just throw it again otherwise.
Of course, in order to catch a PDOException you have to enable it for PDO.
1) In Slim you should use the container (service factory) to build the PDO object. Example:
$container['db'] = function (Container $container) {
$settings = $container->get('settings');
$host = $settings['db']['host'];
$dbname = $settings['db']['database'];
$username = $settings['db']['username'];
$password = $settings['db']['password'];
$charset = $settings['db']['charset'];
$collate = $settings['db']['collate'];
$dsn = "mysql:host=$host;dbname=$dbname;charset=$charset";
$options = [
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_PERSISTENT => false,
PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES $charset COLLATE $collate"
];
return new PDO($dsn, $username, $password, $options);
};
2) You must set the PDO options into the constructor to make it work. Example:
$options = [
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
];
$pdo = new PDO($dsn, $username, $password, $options);
Is there a way to setup a Pdo object to throw a custom exception instead of the default PDOException?
For example:
class MyCustomDbException extends PDOException{}
$pdo = new Pdo("mysql:host=localhost;dbname=myapp", "user_name", "secret_password");
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdo->setAttribute(PDO::ATTR_EXCEPTION_CLASS, "MyCustomDbException");
try {
// Code is here
} catch (PDOException $e) {
// See exception manual if you want to path through message or anything else from pdo exception.
throw new YourException('PDO exception was thrown');
}
http://php.net/manual/en/language.exceptions.extending.php
to see how you can path through parameters.
I'm using the following script to use a database using PHP:
try{
$db = new PDO('mysql:host='.$host.';port='.$port.';dbname='.$db, $user, $pass, $options);
}
catch(Exception $e){
$GLOBALS['errors'][] = $e;
}
Now, I want to use this database handle to do a request using this code:
try{
$query = $db->prepare("INSERT INTO users (...) VALUES (...);");
$query->execute(array(
'...' => $...,
'...' => $...
));
}
catch(Exception $e){
$GLOBALS['errors'][] = $e;
}
Here is the problem:
When the connection to the DB is OK, everything works,
When the connection fails but I don't use the DB, I have the $GLOBALS['errors'][] array and the script is still running afterwards,
When the connection to the DB has failed, I get the following fatal error:
Notice: Undefined variable: db in C:\xampp\htdocs[...]\test.php on line 32
Fatal error: Call to a member function prepare() on a non-object in C:\xampp\htdocs[...]\test.php on line 32
Note: Line 32 is the $query = $db->prepare(...) instruction.
That is to say, the script crashes, and the try/catch seems to be useless. Do you know why this second try/catch don't works and how to solve it?
Thanks for the help!
EDIT: There are some really good replies. I've validated one which is not exactly what I wanted to do, but which is probably the best approach.
try/catch blocks only work for thrown exceptions (throw Exception or a subclass of Exception must be called). You cannot catch fatal errors using try/catch.
If your DB connection cannot be established, I would consider it fatal since you probably need your DB to do anything meaningful on the page.
PDO will throw an exception if the connection cannot be established. Your specific problem is that $db is not defined when you try to call a method with it so you get a null pointer (sort of) which is fatal. Rather than jump through if ($db == null) hoops as others are suggesting, you should just fix your code to make sure that $db is either always defined when you need it or have a less fragile way of making sure a DB connection is available in the code that uses it.
If you really want to "catch" fatal errors, use set_error_handler, but this still stops script execution on fatal errors.
In PHP7, we now can using try catch fatal error with simple work
try {
do some thing evil
} catch (Error $e) {
echo 'Now you can catch me!';
}
But usualy, we should avoid using catch Error, because it involve to miss code which is belong to programmer's reponsibility :-)
I will not report what has already been written about testing if $db is empty. Just add that a "clean" solution is to artificially create an exception if the connection to the database failed:
if ($db == NULL) throw new Exception('Connection failed.');
Insert the previous line in the try - catch as follow:
try{
// This line create an exception if $db is empty
if ($db == NULL) throw new Exception('Connection failed.');
$query = $db->prepare("INSERT INTO users (...) VALUES (...);");
$query->execute(array(
'...' => $...,
'...' => $...
));
}
catch(Exception $e){
$GLOBALS['errors'][] = $e;
}
Hope this will help others!
If database connection fails, $db from your first try .. catch block will be null. That's why later you cannot use a member of non-object, in your case $db->prepare(...). Before using this add
if ($db) {
// other try catch statement
}
This will ensure that you have db instance to work with it.
Try adding the following if statement :
if ($db) {
$query = $db->prepare("INSERT INTO users (...) VALUES (...);");
$query->execute(....);
}
else die('Connection lost');
try{
if(!is_null($db))
{
$query = $db->prepare("INSERT INTO users (...) VALUES (...);");
$query->execute(array(
'...' => $...,
'...' => $...
));
}
}
catch(Exception $e){
$GLOBALS['errors'][] = $e;
}
I am creating a model for a small PHP application. This will utilize PDO to communicate with a MySQL-server. I have understood that the recommended error mode is the one which throws exceptions, as this allows for graceful error handling. But I don't understand how I should handle these exceptions?
Technically, it is easy, but let me give you an example:
class Model()
{
private $host = "localhost",
$user = "",
$pass = "",
$DBH;
function __construct()
{
try
{
$DBH = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
$DBH->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
}
catch(PDOException $e)
{
error_log($e->getMessage());
}
}
}
If I create an object Model in my controller, and it fails, I have no way of handling this in my controller, right? Or what happens when I create that object, "new Model" returns false?
Excuse me for being a newbie, but I want to be able to handle any exceptions also from other functions in the model. How should I go about this? I need to be able to know if something went wrong in my controller and be able to do the appropriate thing there.
If you want your controller to catch the exception as well, you can always rethrow it after logging.
class Model()
{
...
function __construct()
{
try
{
...
}
catch(PDOException $e)
{
error_log($e->getMessage());
throw $e;
}
}
}
Depends entirely on what the error_log function does.
You can return the exception.
You can simply die after logging the error (presumably if your application can't hit the DB then theres no graceful recovery).
You can return a custom exception via throw();
It's really just your preference.