hasOneThrough(SupplyChainLinkMerchant::class, SupplyChain::class); } /** * * 关联商户类型 * */ public function merchantType() { return $this->hasOne(MerchantType::class, 'mer_type_id', 'type_id'); } /** * * 关联商户类别 * */ public function category() { return $this->hasOne(MerchantCategory::class, 'merchant_category_id', 'category_id'); } }