php - 多列关联时如何定义Laravel关系

Question

就像我在下面提到的那样，我有模型，如何在其上实现 laravel eloquent-relationship？

用户模型

id
name

后模型

id
title
desc
created_by = foreign key on User->id

第一阶段（PostStageOneModel）

id
post_id
assigned_by
assigned_to

第二阶段（PostStageTwoModel）

post_id
assigned_by  = foreign key on User->id
assigned_to  = foreign key on User->id

第三阶段（PostStageThreeModel）

post_id
assigned_by  = foreign key on User->id
assigned_to  = foreign key on User->id

第四阶段（PostStageFourModel）

post_id
assigned_by  = foreign key on User->id
assigned_to  = foreign key on User->id

第五阶段（PostStageFiveModel）

post_id
assigned_by  = foreign key on User->id
assigned_to  = foreign key on User->id

第六阶段（PostStageSixModel）

post_id
assigned_by  = foreign key on User->id
assigned_to  = foreign key on User->id

Answer 1

关系可以指定它们使用的列：

public function assigner(){
    return $this->belongsTo(User::class, 'assigned_by');
}
public function assignee(){
    return $this->belongsTo(User::class, 'assigned_to');
}

Answer 2

用户模型应具有如下hasMany关系类型：

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class User extends Model {
    //...
    public function posts() {
        return $this->hasMany(Post::class);
    }
}

帖子通过 created_by 属性属于用户

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Post extends Model {
    //...
    public function createdBy() {
        return $this->belongsTo(User::class, 'created_by');
    }
}

PostStageOneModel 属于帖子和使用 2 个不同属性的用户

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class PostStageOneModel extends Model {
    //...
    public function post() {
        return $this->belongsTo(Post::class);
    }
    public function assignedTo() {
        return $this->belongsTo(User::class, 'assigned_to');
    }
    public function assignedBy() {
        return $this->belongsTo(User::class, 'assigned_by');
    }
}

希望这有帮助

Answer 3

我通过定义以下关系来做到这一点

在 PostStageOneModel 模型中

public function assignedPost() {
    return $this->belongsTo(Post::class, 'post_id', 'post_id');
}

public function assigner()
{
    return $this->belongsTo(User::class, 'assigned_by', 'id');
}

public function assignee()
{
    return $this->belongsTo(User::class, 'assigned_to', 'id');
}

在后期模型中

public function identifiedBy() {
    return $this->belongsTo(User::class, 'identified_by', 'id');
}

public function postAssignedBy() {
    return $this->hasManyThrough(User::class, PostStageOneModel::class, 'post_id', 'id', 'post_id', 'assigned_by' );
}

public function postAssignedTo() {
    return $this->hasManyThrough(User::class, PostStageOneModel::class, 'post_id', 'id', 'post_id', 'assigned_to' );
}

在用户模型中

public function assigned()
{
    return $this->hasMany(PostStageOneModel::class, 'assigned_by', 'id');
}

public function assignedTo()
{
    return $this->hasMany(PostStageOneModel::class, 'assigned_to', 'id');
}