Laravel 4一对一关系

Question

I would like to have a one to one relationship with a pivot table or by referencing an ID in a table.

I currently have a Films table that has a one to many relationship with a Stock table, each stock item needs a format, however I would like the formats to be a set list of formats so I created a Formats table that only has 2 columns ID and Name

Normally I would just add a Format_ID column to the Stock table however I'm unsure how this would work with the Eloquent ORM or if it's even possible / best practice

Sorry if this is hard to understand, cant quite figure out the best way of explaining it

Answer 1

The structure you desire is pretty standard practice. It's quite possible!

Which Eloquent relationship you'd use depends on the direction of the relationship. Each Stock has one Format (one-to-one). But each Format can be assigned to multiple Stock (one-to-many).

For the former, your Stock Eloquent model would have a hasOne() one-to-one relationship.

class Stock extends Eloquent {

    public function format()
    {
        return $this->hasOne('Format');
    }
}

For the latter, your Format eloquent model would have a hasMany() one-to-many relationship.

class Format extends Eloquent {

    public function stock()
    {
        return $this->hasMany('Stock');
    }
}

Note that having both of these defined is totally acceptable and normal. It really just depends on which direction you need your relationship to go. If you never need to look up what Stock belongs to a specific Format , you don't need the one-to-many relationship.

Also note that you may need to add a column key parameter if your column names are not easily guessable by Eloquent. Eg:

return $this->hasOne('Format', 'my_format_id');