how to perform additional inner join on pivot table with laravel eloquent

问题

I have four tables:

foods: id, name
users: id, name
mealtypes: id, name
food_user: id, food_id, user_id, mealtype_id

foods and user have a many-to-many relationship mealtype has a one-to-one relationship with food_user

In the end I would like to have an instance of a model with the following properties: food.name, users.name, mealtype.name

normal sql would be:

SELECT f.name, u.name, m.name FROM foods f
INNER JOIN food_user fu ON f.id = fu.food_id
INNER JOIN users u ON fu.id = u.id 
INNER JOIN mealtypes m ON fu.mealtype_id = m.id

Thanks for any help!

回答1:

You could do something like this with Eloquent and Query Builder, assuming you have a model named Food:

$foods = Food::join('food_user', 'foods.id', '=', 'food_user.food_id')
             ->join('users', 'food_user.user_id', '=', 'users.id')
             ->join('mealtypes', 'food_user. mealtype_id', '=', 'mealtypes.id')
             ->get();

There's a good documentation about the query builder too: http://www.laravel.com/docs/queries

回答2:

To answer my own question a year later. I actually asked the wrong question. A pivot table is just a many-to-many relationship between two tables. If a table that represents this many-to-many relationship additionally relates to other tables it is not a pivot table. So in my case the table food_user should represent an eloquent entity on its own with the three relationships defined.

Update, generic solution:

I cannot give you my final solution in terms of Eloquent, since I haven't used it in ages (and didn't implement it there), so I do not have the knowledge anymore. In more general terms, one would need to create 4 models: