laravel - self 加入 Eloquent

Question

你会如何写一个self join in eloquent？我需要在模型上定义关系吗？

这是我的声明:

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

Answer 1

您可以简单地定义与自身的关系。

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

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