Laravel的動態關係加載

Laravel的負載方法提供了一種靈活的方法，可以在現有模型或集合上急切地負載關係。這種方法可以防止n 1查詢問題，同時允許您僅在必要時加載關係。

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<!-- Syntax highlighted by torchlight.dev -->$post->loadMissing(['comments', 'author']);
// With constraints
$post->loadMissing(['comments' => function($query) {
    $query->latest()->take(5);
}]);

當具有可選的不同部分需要不同的關係數據的可選或儀表板時，此功能尤其有價值。

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<!-- Syntax highlighted by torchlight.dev --><?php

namespace App\Http\Controllers;

use App\Models\Dashboard;
use Illuminate\Http\Request;

class DashboardController extends Controller
{
    public function show(Request $request, Dashboard $dashboard)
    {
        // Load base relationships
        $dashboard->loadMissing([
            'widgets',
            'owner',
        ]);

        // Conditionally load additional data
        if ($request->section === 'analytics') {
            $dashboard->loadMissing([
                'widgets.viewHistory' => function($query) {
                    $query->whereBetween('viewed_at', [
                        now()->subDays(30),
                        now()
                    ]);
                },
                'widgets.interactions'
            ]);
        }

        if ($request->section === 'sharing') {
            $dashboard->loadMissing([
                'sharedUsers',
                'shareLinks' => function($query) {
                    $query->where('expires_at', '>', now());
                }
            ]);
        }
        return $dashboard;
    }
}

以下是儀表板數據加載程序的示例：

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<!-- Syntax highlighted by torchlight.dev -->// GET /dashboard/1?section=analytics
{
    "id": 1,
    "name": "Sales Overview",
    "widgets": [
        {
            "id": 1,
            "type": "chart",
            "viewHistory": [
                {
                    "viewed_at": "2024-02-01T10:30:00Z",
                    "views": 150
                }
            ],
            "interactions": [
                {
                    "type": "filter_change",
                    "timestamp": "2024-02-01T11:20:00Z"
                }
            ]
        }
    ]
}

>加載提供了一種管理關係加載，優化數據庫查詢的有效方法，同時保持代碼靈活性。

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