Laravel 5 Override Eloquent Save Method

Question

I have composite primary keys so Laravel's save() method didn't work. Therefore I need to override the save method. For example, my primary key is a composite key consisting of column_a and column_b. Can you give me example how to override the save method and where I put it?

My Primary Key: column_a, column_b

I've tried the followings:

protected function setKeysForSaveQuery(Builder $query)
{
    parent::setKeysForSaveQuery($query);
    $query->where('locale', '=', $this->locale);
    return $query;
}

I found above code, but it causes 500 Internal Server Error even I call a method that only reads value from database. I have set $primaryKey = 'column_a' and 'locale' (inside where) to column_b. I didn't know what $this->locale refers to?

Here is another way I found, but it failed too

protected $secondaryKey = 'column_b';
function newQuery()
{
    $query = parent::newQuery();
    $query->where($this->secondaryKey, '=', $this->type);
    return $query;
}

Again, I didn't know what $this->type refers to.

Answer 1

I have found the solution. In the model, add primaryKey variable and the following function

protected $primaryKey = array('column1','column2');

protected function setKeysForSaveQuery(\Illuminate\Database\Eloquent\Builder $query) {
    if (is_array($this->primaryKey)) {
        foreach ($this->primaryKey as $pk) {
            $query->where($pk, '=', $this->original[$pk]);
        }
        return $query;
    }else{
        return parent::setKeysForSaveQuery($query);
    }
}

Source: https://github.com/laravel/framework/issues/5517#issuecomment-113655441