markdown SQLSTATE [42000]：迁移命令时指定的键太长错误

Posted 2021-05-06

## Error
> [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
* Update to newerst MySQL version
* Change charaset from utf8mb4
* Change the maximum value of the column so that the character string of 767 bytes or more is not included

```
$ find / -name AppServiceProvider.php
$ vim app/Providers/AppServiceProvider.php
```

```
use Illuminate\Support\Facades\Schema;

public function boot()
{
    Schema::defaultStringLength(191);
}
```


## Reference link

[Laravel 5.4: Specified key was too long error](https://laravel-news.com/laravel-5-4-key-too-long-error)