Laravel雄辩的自我加入父母子女

本文介绍了Laravel雄辩的自我加入父母子女的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 class Product_category extends Model { // protected $table='PRODUCT_CATEGORIES'; public $timestamps = false; public function getParentCategory() { return $this->hasOne(self::class, 'id', 'parent_id'); }. public function getChildCategories(){ return $this->hasMany(self::class, 'parent_id','id'); }

我能够通过使用getChildeCategories来检索表的所有子记录，但无法检索特定类别的Parent. 它总是给我空值.

I am able to retrieve all child records of table by making use of getChildeCategories but not able to retrieve Parent of particular category. It always gives me null.

推荐答案

这称为一对多关系，hasMany关系的逆是belongsTo方法，您的getParentCategory()应为:

It's called one-to-many relationship, the inverse of a hasMany relationship is belongsTo method, your getParentCategory() should be:

public function getParentCategory() { return $this->belongsTo(self::class, 'parent_id'); } public function getChildCategories(){ return $this->hasMany(self::class, 'parent_id'); }