Laravel 连接表以获取每个表的属性

Posted 2023-05-09

【中文标题】Laravel 连接表以获取每个表的属性

【英文标题】：Laravel join tables to get attribute from each one

【发布时间】：2020-03-27 22:21:59

【问题描述】：

我有这 3 个表：

warehouses: id | warehouse_name 

---

good_quantities: id | good_id | warehouse_id | quantity

---

goods: id | good_name

我正在尝试以大量获取所有记录，并希望在 View 中显示它，如下所示：

good_name | warehouse_name | quantity |

使用 Eloquent 获得此结果的正确查询是什么？

好模特

class Good extends Model


/**
 * Get the Good Quantity for this Good.
 */
public function good_quantities()

    return $this->hasMany('App\Models\Good_Quantity','good_id');

仓库模型

class Warehouse extends Model

/**
 * Get the Goods Quantity for this Warehouse.
 */
public function good_quantities()

    return $this->hasMany('App\Models\Good_Quantity','warehouse_id');

Good_Quantity 模型

class Good_Quantity extends Model


/**
 * Get the Good's Info.
 */
public function good()

    return $this->belongsTo('App\Models\Good','good_id');


/**
 * Get the Good Quantity's Warehouse.
 */
public function warehouse()

    return $this->belongsTo('App\Models\Warehouse','warehouse_id');

---

【问题讨论】：

首先，仓库和货物可以使用belongsToMany

了解多对多关系：laravel.com/docs/master/eloquent-relationships#many-to-many

【参考方案1】：

//you can get by using join
//in good model
       function function_name()
$data=App\Good::join('good_quantities','good_quantities.good_id','=','good.good_id')
 ->join('warehouses','warehouses.warehouse_id','=','good_quantities.warehouse_id')
->select('good_name','warehouse_name','quantity')->get();