Self Join in Eloquent

问题

How would you write a self join in eloquent? Would I need to define the relationship on the model?

Here's my statement:

SELECT t2.title FROM products t1, products t2
WHERE t1.id = $id 
AND t2.color_id = t1.color_id AND
t2.id != $id

回答1:

You can simply define a relation to itself.

public function parent()
{
    return $this->belongsTo(self::class, 'color_id');
}

public function children()
{
    return $this->hasMany(self::class, 'color_id');
}

来源：https://stackoverflow.com/questions/30592793/self-join-in-eloquent