SQLSTATE[HY000]: General error: 1 Cannot add a NOT NULL column with default value NULL

laravel 进行单元测试报如下错

 vendor\bin\phpunit --filter a_thread_belongs_to_a_channel
PHPUnit 5.7.27 by Sebastian Bergmann and contributors.

E                                                                   1 / 1 (100%)

Time: 577 ms, Memory: 14.00MB

There was 1 error:

1) Tests\Unit\ThreadTest::a_thread_belongs_to_a_channel
Illuminate\Database\QueryException: SQLSTATE[HY000]: General error: 1 Cannot add a NOT NULL column with default value NULL (SQL: alter table "threads" add column "channel_id" integer not null)

D:\laragon323\www\forum\vendor\laravel\framework\src\Illuminate\Database\Connection.php:647
D:\laragon323\www\forum\vendor\laravel\framework\src\Illuminate\Database\Connection.php:607
D:\laragon323\www\forum\vendor\laravel\framework\src\Illuminate\Database\Connection.php:450
D:\laragon323\www\forum\vendor\laravel\framework\src\Illuminate\Database\Schema\Blueprint.php:86
D:\laragon323\www\forum\vendor\laravel\framework\src\Illuminate\Database\Schema\Builder.php:239
D:\laragon323\www\forum\vendor\laravel\framework\src\Illuminate\Database\Schema\Builder.php:148
D:\laragon323\www\forum\vendor\laravel\framework\src\Illuminate\Support\Facades\Facade.php:221
D:\laragon323\www\forum\database\migrations\2018_06_08_102026_alter_t

查阅了相关资料,尝试了给加默认值方案者不行

Schema::table('organisations', function (Blueprint $table){
    $table->string('long_name')->nullable()->after('default_value');
});

最终如下执行，解决了。

php artisan config:cache

ok! 找到正解！！！

原因

---

貌似开启了缓存，在错误的数据库中运行。实际上是需要忽略测试连接，因本地用的是mysql库，而测试环境下使用的内存级数据库:memory: sqlite

为了解决这个原始错误，我刚刚创建了一个MySQL数据库进行测试。用AppyEnv=测试创建一个.nv.file文件，然后在PHPUnIT.xml中更改了Env。

 "APP_ENV" value="testing"/>

再次，确定有否安装相关的composer包

composer require doctrine/dbal --dev