Try catch for laravel is not working for duplicate entry

Question

I am using below code in laravel controller. And getting duplicate error for username but I need to handle it by try-catch. This code is not working.

<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use App\Http\Requests;
use App\Http\Controllers\Controller;
use Response;
use DB;

class StaffController extends Controller
{
    public function saveMember(Request $request){
        $errormsg = "";
        $result = false;
        try{
            $result = DB::table('members')->insert(
                    [
                        'username' => $request->username,
                        'phone' => $request->phone,
                        'status' => 1
                    ]
                );
        }catch(Exception $exception)
        {
            $errormsg = 'Database error! ' . $exception->getCode();
        }
        return Response::json(['success'=>$result,'errormsg'=>$errormsg]);
    }
}

I am getting this error, which I need to handle by try and catch

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'test1' for key 'username' 

Thanks for your help.

Solution 1

You need to make Exception as global,

1. Either by using.

   use Exception;
   

and then use

catch(Exception $exception)

2. Or by using

   catch(\Exception $exception)
   

Instead of this

catch(Exception $exception)

Solution 2

you can easily avoid this try & catch block by first validating the uniqness of the username against the desired column in your db table. you can do it with your $request object or (better) by setting a custom Request class that will do this validation before excecution the controller method. https://laravel.com/docs/5.1/validation#rule-unique

Comments

[Jija]

Yes, I will apply you suggestion later, but my question was why try-catch is not working, although it solved, thanks for your ans.

[John Little]

Why does this work? I.e. why is catch(Exception $exception) failing to catch the exception?

[Niklesh Raut]

@JohnLittle : Are you able to catch error with catch(Exception $exception) without using use Exception; at the top ? Or you are pointing to any other thing ?

[John Little]

I was trying just "catch(Exception $exception)" without "use Exception". I changed it to "catch(\Exception $exception)" and it worked. I would have assumed that if Exception was not resolved, it would have thrown an error when it parses the try/catch? Is \Exception clarifying the namespace? Is \ not default?

[elfif]

Even if i really like Laravel, i think using try/catch and an exception to detect possible duplicate is the most robust solution, hands down. Using a validation is cool and will prevent the issue in most case but you need to think about concurrency with a lot of connections and users. Even if it's unlikely shit can happen... Or someone might just try to make it crash using that kind of tricks.

[Synchro]

This approach creates a race condition. The only certain way to avoid that is to use a transaction that wraps both your validation check and the insert/update.