Laravel |使用

首先,命名列的常见做法是 snake_case bookid 作为 book_id CamelCase . 所以不是 usertransactions 最好是写作 userTransactions .

让我们回到你的问题上来。既然你的回答中有book_id,你应该能够在 UserTransaction 和 Book Book model

public function userTransactions() {
    return $this->belongsToMany(UserTransaction::class); //it can be one to many or many to many base on your logic. I assume Many to many
}

然后您应该在中定义反向关系 UserTransaction model :

public function books(){
    return $this->belongsToMany(Book::class);
}

现在可以使用 load 方法类似 $usertransactions = $user->usertransactions->load('books')

https://laravel.com/docs/5.6/eloquent-resources

你的关系是多对多的。

看看这个: https://laravel.com/docs/5.6/eloquent-relationships#many-to-many

return$this->belongstomny('App\Book','transactions','user'u id','Book'u id');

如果需要,使用select或pull设置数据格式。

Eloquent: API Resources :

您必须创建一个Usertransaction资源,假设您在Usertransaction和Book模型之间有一对一的关系:

<?php

namespace App\Http\Resources;

use Illuminate\Http\Resources\Json\JsonResource;

class Usertransaction extends JsonResource
{
    /**
     * Transform the resource into an array.
     *
     * @param  \Illuminate\Http\Request
     * @return array
     */
    public function toArray($request)
    {
        return [
            'id' => $this->id,
            'Bookid' => $this->book->bookid,
            'Bookname' => $this->book->bookname 
        ];
    }
}

最后,在控制器中可以执行以下操作:

use App\Usertransaction;
use App\Http\Resources\Usertransaction as UsertransactionResource;

function YourMethod() {
    $usertransactions = $user->usertransactions;
    return UsertransactionResource::collection($usertransactions);
}

附言:笔也可以这样做:)