yii2 log输出到file及database

'bootstrap' => [
    'log'
],

'components' => [
    'log' => [
        'targets' => [
            [
                'class' => 'yii\log\FileTarget',
                'exportInterval' => 1,
            ],
        ],
    ],

'log' => [
    'targets' => [
        [
            'class' => 'yii\log\DbTarget',
            'levels' => ['error', 'warning', 'trace'],
        ]
    ]
],

./yii migrate --migrationPath=@yii/log/migrations/

'components' => [
    'log' => [
        'traceLevel' => YII_ENV == 'dev' ? 3 : 0,
        'targets' => [
            [
                'class' => 'yii\log\DbTarget',
                'levels' => YII_DEBUG ? ['error', 'warning', 'trace'] : ['error'],
            ],
            [
                'class' => 'yii\log\FileTarget',
                'levels' => YII_DEBUG ? ['error', 'warning', 'trace'] : ['error', 'warning'],
            ],
        ],
    ],
],