Question

我有一些特定的数据库结构，如下图所示

因此，基本上一个零件可以具有多个规格，但是这些规格在已知表中不存在。规格可以在任何 rsnf_part_specification ， rgr_part_specification 或 dcd_part_specification 表中。我需要找到一种方法来通过 part_owner_short_code FK来了解哪个表，因为它的规格表以 rsnf，dcd或rgr 为前缀。

是否可以使用Laravel 5.6口才关系做到这一点？

Answer 1

您必须像这样修改表结构

owners(id, code, status)
parts(id, owner_id, category_id, name) //should add owner_id as FK 
part_specifications(id, part_id, name, description) //no need to prefix owner code

所有者模型

class Owner extend Model {
    protected $table = 'owners';

    public function parts(){
        return $this->hasMany('App\Part', 'owner_id');
    }

    public function partSpecification(){
        return $this->hasManyThrough('App\PartSpecification', 'App\Part', 'owner_id', 'part_id');
    }

}

零件模型

class Part extend Model {
    protected $table = 'parts';

    public function owner(){
        return $this->belongsTo('App\Owner', 'owner_id');
    }

    public function category(){
        return $this->belongsTo('App\Category', 'category_id'); // Define Category model
    }
}

零件规格模型

class PartSpecification extend Model {
    protected $table = 'part_specifications';

    public function part(){
        return $this->belongsTo('App\Part', 'part_id');
    }
}

编辑：

如果要使用现有的规范结构，请尝试

所有者模型

class Owner extend Model {
    protected $table = 'owners';

    public function parts(){
        return $this->hasMany('App\Part', 'owner_id');
    }
}

零件模型

    class Part extend Model {
        protected $table = 'parts';

        public function owner(){
            return $this->belongsTo('App\Owner', 'owner_id');
        }

        public function category(){
            return $this->belongsTo('App\Category', 'category_id'); // Define Category model
        }

        public function rnsPartSpecification(){
            return $this->hasMany('App\RnsPartSpecification','part_id'); //define RnsPartSpecification model 
        }

        public function rgrPartSpecification(){
            return $this->hasMany('App\RgrPartSpecification','part_id'); //define RgrPartSpecification model 
        }

        public function dcdPartSpecification(){
            return $this->hasMany('App\DcdPartSpecification','part_id'); //define DcdPartSpecification model 
        }
    }

获取数据

$parts = Part::with('owner', 'RsnfPartSpecification', 'RgrPartSpecification', 'DcdPartSpecification')->get();

foreach($parts as $part){
    if($part->owner->code == 'rsnf'){
        print_r($part->rnsPartSpecification)
    }else if($part->owner->code == 'rgr'){
        print_r($part->rgrPartSpecification)
    }else{
        print_r($part->dcdPartSpecification)
    }
}

laravel 5.6在多个表上雄辩的一对多关系

1 个答案: