Laravel hasMany association with multiple columns

问题

I have two models

model_1
model_2

model_1 has many model_2

Now I want to association model_1 hasMany model_2 match with multiple column.

Let me give an example in raw query

select ...... from model_1 left join model_2 ON (model_1.f1 = model_2.f1 AND model_1.f2 = model_2.f2)

How can I do this in hasMany association

回答1:

I got it to work by adding an additional parameter to join on in the model:

public function my_joined_columns($mySecondJoinColumnValue)
    {
        return $this->hasMany('NamespaceToOtherModel', 'myIdColumn')
           ->where('my_second_join_column', $mySecondJoinColumnValue);
    }

And then I make sure I pass in the parameter:

MyModel1::find(1)->my_joined_columns(2)->get()

回答2:

I faced this situation while dealing with a pre existing schema. I came up with this solution

After installing Compoships and configuring it in your models model_1 and model_2, you can define your relationships matching multiple columns.

In model_1:

public function model_2()
    {
        return $this->hasMany(model_2::class, ['f1', 'f2'], ['f1', 'f2']);
    }

In model_2:

public function model_1()
    {
        return $this->belongsTo(model_1::class, ['f1', 'f2'], ['f1', 'f2']);
    }

Compoships supports eager loading.

回答3:

Official Laravel Docummentation says: http://laravel.com/docs/5.1/eloquent-relationships#one-to-many

来源：https://stackoverflow.com/questions/32471084/laravel-hasmany-association-with-multiple-columns