我想用Laravel Eloquent写这个SQL——选择所有作者的名字都属于一本书 - I want to write this SQL in Laravel Eloquent -select all author names belongs to a book

I want to write this SQL in Laravel Eloquent -select all author names belongs to a book

我想在Laravel Eloquent 中编写这个SQL

SELECT book.book_id,book.book_name,author.author_name,book.price,book.publication   
FROM author,book,book_author
WHERE bookauthor.b_id=book.book_id and bookauthor.a_id=author.author_id

使用雄辩的关系有更好的方法。Book模型应该定义以下关系：

namespace App;
use Illuminate'Database'Eloquent'Model;
class Book extends Model
{
    /**
     * Get the authors for the book.
     */
    public function authors()
    {
        return $this->hasMany('App'Author');
    }
}

作者应该属于这本书：

namespace App;
use Illuminate'Database'Eloquent'Model;
class Author extends Model
{
    /**
     * Get the book of the author.
     */
    public function book()
    {
        return $this->belongsTo('App'Book');
    }
}

如果你只想获得作者的名字，你可以在作者集合上使用reduce方法：

$authors = App'Book::find(1)->authors;
$authorsNames = $authors->reduce(function ($carry, $author) {
    $carry[] = $author->name;
    return $carry;
}, array());

使用Laravel Joins:

  bookauthor::Join('book', 'book.book_id', '=', 'bookauthor.b')
->Join('author','bookauthor.a_id','=','author.author_id')
->select('book.book_id','book.book_name','author.author_name','book.price','book.publication')
->get();

试试这个。祝你好运：）