具有自定义名称的 hasMany、belongsTo、belongsToMany 参数？答案

【问题标题】：hasMany, belongsTo, belongsToMany parameters with custom names?具有自定义名称的 hasMany、belongsTo、belongsToMany 参数？
【发布时间】：2021-04-12 07:36:28
【问题描述】：

我有这些数据库表：

author (atr_id pk)                              // model : Author
category (ctg_id pk)                            // model : Category
post (pst_id pk, pst_atr_id fk)                 // model : Post
post_categories (pct_pst_id fk, pct_ctg_id fk)  // pivot : PostCategories

如何定义自定义名称的hasMany、belongsTo、belongsToMany参数？

型号：作者

public function getPosts()
{
    return $this->hasMany('App\Post', ?, ?);
}

型号：帖子

public function getAuthor()
{
    return $this->belongsTo('App\Author', ?, ?);
}

public function getCategories()
{
    return $this->belongsToMany('App\Category', ?, ?, ?);
}

型号：类别

public function getPosts()
{
    return $this->belongsToMany('App\Post', ?, ?, ?);
}

【问题讨论】：

显示这些表的数据库结构？
你的意思是自定义外键？

标签： laravel laravel-5 eloquent

【解决方案1】：

型号：作者

<?php

public function getPosts(){
     return $this->hasMany('App\Post','pst_atr_id');// author table's foreign key in Post table.
}

模型：帖子

<?php

 public function getAuthor(){
     return $this->belongsTo('App\Author','pst_atr_id','atr_id'); // first is foreign key of author table in this current table and second is primary key name of author table.
 }

 public function getCategories(){
     return $this->belongsToMany('App\Category','post_categories','pct_pst_id ','pct_ctg_id'); /* 'post_categories' is the pivot table. Rest 2 parameters- first is foreign key present in post_categories of the current model, second is foreign key present in post_categories of the model we are relating with*/
 }

型号：类别

<?php

 public function getPosts(){
      return $this->belongsToMany('App\Post','post_categories ','pct_ctg_id','pct_pst_id');

    /* 'post_categories' is the pivot table. Rest 2 parameters- first is foreign key present in post_categories of the current model, second is foreign key present in post_categories 
     of the model we are relating with*/
 }

【讨论】：

【解决方案2】：

Author   : $this->hasMany('App\Post', 'pst_atr_id', 'atr_id');

Post     : $this->belongsTo('App\Author', 'pst_atr_id', 'atr_id');

Post     : $this->belongsToMany('App\Category', 'post_categories', 'pct_pst_id', 'pct_ctg_id');

Category : $this->belongsToMany('App\Post', 'post_categories', 'pct_ctg_id' 'pct_pst_id');

【讨论】：

【解决方案3】：

型号：作者

public function getPosts()
{
    return $this->hasMany('App\Post', 'pst_id', 'atr_id');
}

型号：帖子

public function getAuthor()
{
    return $this->belongsTo('App\Author', 'pst_atr_id', 'pst_id');
}

public function getCategories()
{
    return $this->belongsToMany('App\Category', 'post_categories', 'pct_pst_id', 'pct_ctg_id');
}

型号：类别

public function getPosts()
{
    return $this->belongsToMany('App\Post', 'post_categories', 'pct_ctg_id', 'pct_pst_id');
}

【讨论】：