这是我的第一个 Laravel 项目，请耐心等待。我正在尝试显示父->子层次结构(非递归)，类似于下面的内容:
- 类别 1
- ----列表项
- ----------资源 1
- ----列表项
- ----------资源 2
- 类别 2
- -----列出第1项
- -----列出第 2 项....等
我不知道如何编写查询来获取链接到 subStatement 的资源，而不是顶级类别，基本上是与 SubStatement 相关的内部联接。目前显示如下；
{
"id": 1,
"name": "Category 1: Practising plumbing overview",
"description": "<p>Category 1: Practising plumbing overview</p>",
"created_at": "2022-01-06 15:48:49",
"updated_at": "2022-01-06 15:48:49",
"deleted_at": null,
"plumbing_area_id": 1,
"category_id": 1,
"SubStatement": [
{
"id": 1,
"title": "Plying narrative for Category 1",
"description": "<p>Body of content.</p>",
"theme_id": 1,
"plumbing_area_id": 1
},
{
"id": 2,
"title": "Lay narrative for Category 1",
"description": "<p>body description.</p>",
"theme_id": 1,
"plumbing_area_id": 1
}
],
"resources": []
},
{
"id": 2,
"name": "Category 2: AAV Practising plumbing introduction",
"description": "<p><strong>Category 2:</strong> AAV Practising plumbing introduction</p>",
"created_at": "2022-01-06 15:49:12",
"updated_at": "2022-01-06 15:49:12",
"deleted_at": null,
"plumbing_area_id": 1,
"category_id": 1,
"SubStatement": [
{
"id": 3,
"title": "Plying narrative for Category 2",
"description": "<p>Body of content;</p>",
"theme_id": 2,
"plumbing_area_id": 1
},
{
"id": 4,
"title": "Lay narrative for Category 2",
"description": "<p>Body of content</p>",
"theme_id": 2,
"plumbing_area_id": 1
}
],
"resources": []
},
{
"id": 3,
"name": "Category 3: AAV Practising plumbing design",
"description": "<p><strong>Category 3: </strong>AAV Practising plumbing design</p>",
"created_at": "2022-01-06 15:49:47",
"updated_at": "2022-01-06 15:49:47",
"deleted_at": null,
"plumbing_area_id": 1,
"category_id": 1,
"SubStatement": [
{
"id": 5,
"title": "Plying narrative for Category 3",
"description": "<p>Body of content;</p>",
"theme_id": 3,
"plumbing_area_id": 1
},
{
"id": 6,
"title": "Lay narrative for Category 3",
"description": “Blah blah</p>",
"theme_id": 3,
"plumbing_area_id": 1
}
],
"resources": []
},
{
"id": 4,
"name": "Category 4: another “category,
"description": “Body</p>",
"created_at": "2022-01-06 15:50:04",
"updated_at": "2022-01-06 15:50:04",
"deleted_at": null,
"plumbing_area_id": 1,
"category_id": 1,
"SubStatement": [
{
"id": 7,
"title": "Plying narrative for Category 4",
"description": "<p>sdfsdfsdf;</p>",
"theme_id": 4,
"plumbing_area_id": 1
},
{
"id": 8,
"title": "Lay narrative for Category 4",
"description": "<p> sdfsdfsdfsdf</p>",
"theme_id": 4,
"plumbing_area_id": 1
}
],
"resources": []
},
]
我正在寻找类似下面的内容，请注意资源节点在哪里:
[
{
"id": 1,
"name": "Category 1: Practising plumbing overview",
"description": "<p>Category 1: Practising plumbing overview</p>",
"created_at": "2022-01-06 15:48:49",
"updated_at": "2022-01-06 15:48:49",
"deleted_at": null,
"plumbing_area_id": 1,
"category_id": 1,
"SubStatement": [
{
"id": 1,
"title": "Plying narrative for Category 1",
"description": "<p>Body of content.</p>",
"theme_id": 1,
"plumbing_area_id": 1,
"resources": [
{
"id": 1,
"resource_title": "The name of the resource"
}
]
}
]
}
]
//主题模型
{
return $this->hasMany(Statement::class, 'theme_id', 'id');
}
public function resources()
{
return $this->belongsToMany(Resource::class);
}
//下面的Controller正在输出上面的JSON
{
$output = Theme::where ( 'category_id', '=', $category_id )
->with(['subStatement' =>
fn ($query) =>
$query->select('id','title','description','theme_id','therapy_area_id')
])
->with(['resources' =>
fn ($query) =>
$query->select('id','temporary_url')])
->get();
}
//我尝试写这样的东西。它引发了“违反完整性约束:1052 字段列表中的列'id'不明确”错误
{
return $this->hasOneThrough(Statement::class, Resource::class);
}
最佳答案
您的主要问题是您需要嵌套查询。
我将首先根据您的架构将关系添加到您的模型中。
然后，如果我正确理解您想要实现的目标，我将添加嵌套的基本查询。
型号
主题.php
public function subStatements()
{
return $this->hasMany(Statement::class); // 1-N
}
public function statements()
{
return $this->belongsToMany(Statement::class); // N-N
}
public function resources
{
return $this->belongsToMany(Resource::class); // N-N
}
Statement.php
public function theme()
{
return $this->belongsTo(Theme::class); // 1-N
}
public function themes()
{
return $this->belongsToMany(Theme::class); // N-N
}
public function resources
{
return $this->belongsToMany(Resource::class); // N-N
}
Resource.php
public function themes()
{
return $this->belongsToMany(Theme::class); // N-N
}
public function statements()
{
return $this->belongsToMany(Statement::class); // N-N
}
查询
$themes = Theme::query()
->where('category_id', $category_id)
->with([
'subStatements' => fn ($query) => $query->with('resources')
])
->get();
关于php - Laravel 8 嵌套模型关系，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/70704555/