[SOLVED] Laravel 5.5 Specified key was too long max key length is 767 bytes

Laravel 5.5 Tutorial for beginners, this lesson will show you how to FIX importan error in laravel 5.5 about  SQLSTATE[42000]: Syntax error or access violation.

767 bytes is the stated prefix limitation for InnoDB tables in MySQL version 5.6 (and prior versions). It's 1,000 bytes long for MyISAM tables. In MySQL version 5.7 and upwards this limit has been increased to 3072 bytes.

You also have to be aware that if you set an index on a big char or varchar field which is utf8mb4 encoded, you have to divide the max index prefix length of 767 bytes (or 3072 bytes) by 4 resulting in 191. This is because the maximum length of a utf8mb4 character is four bytes. For a utf8 character it would be three bytes resulting in max index prefix length of 254.

Laravel 5.4 / 5.5 made a change to the default database character set, and it’s now utf8mb4 which includes support for storing emojis. This only affects new applications and as long as you are running MySQL v5.7.7 and higher you do not need to do anything.

For those running MariaDB or older versions of MySQL you may hit this error when trying to run migrations:

[Illuminate\Database\QueryException]
SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes (SQL: alter table users add unique users_email_unique(email))
[PDOException]
SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes

Solution

As outlined in the Migrations guide to fix this all you have to do is edit your AppServiceProvider.php (app\Providers\AppServiceProvider.php) file and inside the boot method set a default string length:

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;
use Illuminate\Support\Facades\Schema;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
         Schema::defaultStringLength(191);
    }

    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        //
    }
}

After that everything should work as normal.