php - hasManyThrough关系返回错误的SQL语句

Question

我想获取一些没有直接关系的表的数据。上下文如下:

//** account_table **// Normal user, who can buy any book
account_id
account_info

//** book_table **// Books
book_id
account_id
author_id

//** author_table **// Author, who can write a lot of books (they will have more functions, this is the why i choose to create other table)

author_id
book_id
author_desc

我使用的模型是:

class Account extends Eloquent implements UserInterface, RemindableInterface {
    protected $table = 'account_table';
    protected $primaryKey = 'account_id';

    public function Book()
    {
        return $this->hasMany('Book', 'account_id');
    }

    public function Author()
    {
        return $this->hasManyThrough('Author', 'Book','account_id','book_id');
    }
}

class Book extends Eloquent implements UserInterface, RemindableInterface {
    protected $table = 'book_table';
    protected $primaryKey = 'book_id';

    public function Account()
    {
        return $this->belongsTo('Account','account_id');
    }

    public function Author()
    {
        return $this->hasOne('Author', 'author_id', 'author_id');
    }  
}

class Author extends Eloquent implements UserInterface, RemindableInterface {
    protected $table = 'author_table';
    protected $primaryKey = 'author_id';

    public function Book()
    {
        return $this->belongsToMany('Book', 'author_id');
    }
}

因此，为了获取此信息，我使用以下代码:

$user = Account::find(166); //user
dd($user->Author);

输出会抛出这样的错误:

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'book.id' in 'on clause' (SQL: select `author_table`.*, `book_table`.`account_id` from `author_table` inner join `book_table` on `book_table`.`id` = `author_table`.`book_id` where `book_table`.`account_id` = 166)

它似乎正在寻找一个在我的数据库中不存在的字段 (id)，但是我已经在模型中定义了所有主键。在这种情况下，我应该怎么做才能获得 author_desc 信息？

编辑(其他示例):

当我使用以下代码时，它检索到相同的错误:

$user = Account::find(166);
echo Book::find(3);

Answer 1

您已经使用 hasOne() 方法定义了 Book 与 Author 的一对一关系，并使用 belongsToMany( ) 方法。相反，这些应该是反向关系。尝试用 belongsTo() 方法替换 belongsToMany() 方法。像这样:

class Account extends Eloquent implements UserInterface, RemindableInterface {
    protected $table = 'account_table';
    protected $primaryKey = 'account_id';

    public function Book()
    {
        return $this->hasMany('Book', 'account_id');
    }

    public function Author()
    {
        return $this->hasManyThrough('Author', 'Book','account_id','book_id');
    }
}

class Book extends Eloquent implements UserInterface, RemindableInterface {
    protected $table = 'book_table';
    protected $primaryKey = 'book_id';

    public function Account()
    {
        return $this->belongsTo('Account','account_id');
    }

    public function Author()
    {
        return $this->hasOne('Author', 'author_id', 'author_id');
    }  
}

class Author extends Eloquent implements UserInterface, RemindableInterface {
    protected $table = 'author_table';
    protected $primaryKey = 'author_id';

    public function Book()
    {
        return $this->belongsTo('Book', 'author_id');
    }
}