Php 我想用Laravel Eloquent编写这个SQL—选择属于一本书的所有作者姓名

我想用Laravel雄辩地编写这个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

---

有一种更好的方法使用。图书模型应定义以下关系：

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');
    }
}

如果只想获取作者姓名，可以使用“作者”集合上的方法：

$authors = App\Book::find(1)->authors;

$authorsNames = $authors->reduce(function ($carry, $author) {
    $carry[] = $author->name;
    return $carry;
}, array());

---

有一种更好的方法使用。图书模型应定义以下关系：

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');
    }
}

如果只想获取作者姓名，可以使用“作者”集合上的方法：

$authors = App\Book::find(1)->authors;

$authorsNames = $authors->reduce(function ($carry, $author) {
    $carry[] = $author->name;
    return $carry;
}, array());

使用Laravel连接：

  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：）

使用Laravel连接：

  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：）