优化 Laravel Join 以检索单行中的所有数据而不重复表

Question

我有 4 个 MySQL 表，使用 PHP 和 Laravel 7

1. 成员
2. 扣除
3. 付款
4. 付款扣除额

现在我想连续显示每个会员的单笔付款和所有其他扣除额。 （假设一个人只有一笔付款）

数据库架构如下

这是我要显示的 HTML 表格

这是我正在使用的查询，但它重复了数据。

$payments = Payment::leftJoin('members', 'payments.member_id', '=', 'members.id')
        ->leftJoin('payment_deductions', 'payments.id', '=', 'payment_deductions.payment_id')
        ->leftJoin('deductions', 'payment_deductions.deduction_id', '=', 'deductions.id')
        ->select(
            'members.*',
            'payment_deductions.*',
        )
        ->orderBy("member_id", "ASC")
        ->get()->toArray();

结果数组根据每个成员的推导重复每个成员。

有什么办法可以更好地获取这些数据吗？类似于每个成员的嵌套扣除数组？

这是模型

会员

namespace App;

    use IlluminateDatabaseEloquentModel;
    use CarbonCarbon;

    class Member extends Model
    {
        protected $fillable = [
            'full_name',
            'email',
            'created_by',
        ];
    }

付款

namespace App;

    use IlluminateDatabaseEloquentModel;

    class Payment extends Model
    {
        protected $fillable = [
            'member_id',
            'total_amount',
            'payable_amount',
            'created_by',
        ];

        public function deductions() {
           return $this->belongsToMany(Deduction::class,'payment_deductions')->withTimestamps();
        }
    }

扣除

namespace App;

    use IlluminateDatabaseEloquentModel;

    class Deduction extends Model
    {
        protected $fillable = [
        'title',
        'priority',
        'created_by',
        ];
    }

Answer 1

在构建模型时，您非常接近并且处于正确的轨道上，您缺少的是如何在不创建另一个查询的情况下加载关系，如果您查看控制器，您将看到加载内部关系的标准方法。希望这是一个更好的概念来解决您的担忧。

供参考：https://laravel.com/ docs/9.x/eloquent-relationships#lazy-eager-loading

这样做也可以避免将来的 N+1 问题，请参阅什么是 ORM（对象关系映射）中的“N+1 选择问题”？ 有关 N+1 的详细信息< /p>

会员模型

public class Member extends Model
{
    protected $fillable = [
       'full_name',
       'email',
       'created_by',
    ];
        
    public function payments(){
        return $this->hasMany(Payment::class);
    }
}

支付模式

public class Payment extends Model
{
    protected $fillable = [
       'member_id',
       'total_amount',
       'payable_amount',
       'created_by',
    ];
        
    public function member(){
        return $this->belongsTo(Member::class);
    }

    public function deductions() {
        return $this->belongsToMany(Deduction::class,'payment_deductions')->withTimestamps();
    }
}

推演模型

public class Deduction extends Model
{
    protected $fillable = [
       'title',
       'priority',
       'created_by',
    ];
        
    public function payments() {
        return $this->belongsToMany(Payment::class,'payment_deductions')->withTimestamps();
    }
}

成员控制器：

/**
 * Show the specified model.
 *
 * @param  \Illuminate\Http\Request  $request
 * @param  Member $member
 * @return \Illuminate\Http\Response
 */
public function show(Request $request, Member $member){
    // This will load all of the inner relationships in a single query.
    $member->load('payments.deductions');
        
    //Assign the loaded payments to be used
    $payments = $member->payments;
        
    /* 
        You can acess the payments -> deductions in a foreach loop, in php or blade
        foreach($payments->deductions as $deduction){
           //$deduction->id   
        }
    */  
        
    return view('sampleView', compact('member', 'payments'));
}