Laravel check for constraint violation - php

Question

I was curious if there is a way we can check if there is a constraint violation error when delete or insert a record into the database.
The exception thrown is called 'QueryException' but this can be a wide range of errors. Would be nice if we can check in the exception what the specific error is.

Answer 1

You are looking for the 23000 Error code (Integrity Constraint Violation). If you take a look at QueryException class, it extends from PDOException, so you can access to $errorInfo variable.
To catch this error, you may try:
try {
// ...
} catch (\Illuminate\Database\QueryException $e) {
var_dump($e->errorInfo);
}
// Example output from MySQL
array (size=3)
0 => string '23000' (length=5)
1 => int 1452
2 => string 'Cannot add or update a child row: a foreign key constraint fails (...)'
To be more specific (Duplicate entry, not null, add/update child row, delete parent row...), it depends on each DBMS:
PostgreSQL and SQL server follow the SQL standard's conventions for SQLSTATE code, so you may return the first value from the array $e->errorInfo[0] or call $e->getCode() directly
MySQL, MariaDB and SQLite do not strictly obey the rules, so you need to return the second value from the array $e->errorInfo[1]
For laravel, handling errors is easy, just add this code in your "app/start/global.php" file ( or create a service provider):
App::error(function(\Illuminate\Database\QueryException $exception)
{
$error = $exception->errorInfo;
// add your business logic
});

Answer 2

first put this in your controller
use Exception;
second handle the error by using try catch like this example
try{ //here trying to update email and phone in db which are unique values
DB::table('users')
->where('role_id',1)
->update($edit);
return redirect("admin/update_profile")
->with('update','update');
}catch(Exception $e){
//if email or phone exist before in db redirect with error messages
return redirect()->back()->with('phone_email','phone_email_exist before');
}
New updates here without need to use try catch you can easily do that in validation rules as the following code blew
public function update(Request $request, $id)
{
$profile = request()->all();
$rules = [
'name' => 'required|unique:users,id,'.$id,
'email' => 'required|email|unique:users,id,'.$id,
'phone' => 'required|unique:users,id,'.$id,
];
$validator = Validator::make($profile,$rules);
if ($validator->fails()){
return redirect()->back()->withInput($profile)->withErrors($validator);
}else{
if(!empty($profile['password'])){
$save['password'] = bcrypt($profile['password']);
}
$save['name'] = $profile['name'];
$save['email'] = $profile['email'];
$save['phone'] = $profile['phone'];
$save['remember_token'] = $profile['_token'];
$save['updated_at'] = Carbon::now();
DB::table('users')->where('id',$id)->update($save);
return redirect()->back()->with('update','update');
}
}
where id related to record which you edit.

Answer 3

You may also try
try {
...
} catch ( \Exception $e) {
var_dump($e->errorInfo );
}
then look for error code.
This catches all exception including QueryException

Answer 4

If you are using Laravel version 5 and want global exception handling of specific cases you should put your code in the report method of the /app/Exception/Handler.php file. Here is an example of how we do it in one of our micro services:
public function render($request, Exception $e)
{
$response = app()->make(\App\Support\Response::class);
$details = $this->details($e);
$shouldRenderHttp = $details['statusCode'] >= 500 && config('app.env') !== 'production';
if($shouldRenderHttp) {
return parent::render($request, $e);
}
return $response->setStatusCode($details['statusCode'])->withMessage($details['message']);
}
protected function details(Exception $e) : array
{
// We will give Error 500 if we cannot detect the error from the exception
$statusCode = 500;
$message = $e->getMessage();
if (method_exists($e, 'getStatusCode')) { // Not all Exceptions have a http status code
$statusCode = $e->getStatusCode();
}
if($e instanceof ModelNotFoundException) {
$statusCode = 404;
}
else if($e instanceof QueryException) {
$statusCode = 406;
$integrityConstraintViolation = 1451;
if ($e->errorInfo[1] == $integrityConstraintViolation) {
$message = "Cannot proceed with query, it is referenced by other records in the database.";
\Log::info($e->errorInfo[2]);
}
else {
$message = 'Could not execute query: ' . $e->errorInfo[2];
\Log::error($message);
}
}
elseif ($e instanceof NotFoundHttpException) {
$message = "Url does not exist.";
}
return compact('statusCode', 'message');
}
The Response class we use is a simple wrapper of Symfony\Component\HttpFoundation\Response as HttpResponse which returns HTTP responses in a way that better suits us.
Have a look at the documentation, it is straightforward.

Answer 5

You can add the following code in app/start/global.php file in order to print the exception
App::error(function(QueryException $exception)
{
print_r($exception->getMessage());
});
check this part in the documentation