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queryScope和setAttribute用法

时间:2021-07-01 10:21:17 帮助过:19人阅读

setAttribute

在表单中创建日期,然后直接处理,而不用在controller里面写时间原来的在controller里面写时间

app/Http/Controllers/ArticlesController.php    public function store(Request $requests){        $input = Request::$requests->all();        $input['publish_at']=Carbon::now();  //原来这里是通过直接硬性写时间进去        Articles::create($input);        return redirect('/articles');    }

改为在表单中处理时间

app/Http/Controllers/ArticlesController.php    public function store(Request $requests){ //现在取消掉硬性写时间        Articles::create($requests->all());        return redirect('/articles');    }

(表单)

resources/views/articles/create.blade.php@extends('layout.app')@section('content')    

创建文章

{!! Form::open(['url'=>'/articles/store']) !!} {!! Form::label('title', 'Title:') !!} {!! Form::text('title', null, ['class' => 'form-control']) !!} {!! Form::label('content', 'Content:') !!} {!! Form::textarea('content', null, ['class' => 'form-control']) !!} {!! Form::label('publish_at', 'publish_at:') !!} {!! Form::date('publish_at', date('Y-m-d'), ['class' => 'form-control']) !!} //这里写时间,由用户选择输入 {!! Form::submit('发表文章',['class'=>'btn btn-primary form-control']) !!} {!! Form::close() !!}@stop

在数据库里显示的情况

id  title   content publish_at  created_at  updated_at5   我是一篇新文章 你好  2016-05-21 00:00:00 2016-05-21 07:32:48 2016-05-21 07:32:48 //这里的时间只有日期,而没有时分

所以,引申出一个解决办法,在model里面写方法,通过model跟数据库的关联,从而在写入数据库的时候进行时间格式转换(同理可鉴其他数据的处理)

这就是setAttribute 用法

在model里面写,写一个自动处理的function setattribute

app/Articles.phpclass Articles extends Model{    protected $fillable=['title','content','publish_at'];    public function setPublishAtAttribute($date)    //set + 字段名  + attribute 组成的,laravel会自动判断字段名,并且名字要遵循驼峰命名法    {        $this->attributes['publish_at'] = Carbon::createFromFormat('Y-m-d',$date); //调用model的attributes方法来设置    }}

数据库可以看到数据已经生成,并且时间有时分。

id  title   content publish_at  created_at  updated_at6   我是第二篇文章 爱的飒飒大   2016-05-27 08:17:29 2016-05-21 08:17:29 2016-05-21 08:17:29

原来的setattribute是叫setattribute的,不过也支持这样中间插入一个字段,在debug的过程中也可以看到他的转换过程

in Carbon.php line 425at Carbon::createFromFormat('Y-n-j G:i:s', 'Y-m-d-2016-05-27-21 8:21:00', null) in Carbon.php line 368at Carbon::create('Y-m-d', '2016-05-27', null, null, null, null, null) in Carbon.php line 383at Carbon::createFromDate('Y-m-d', '2016-05-27') in Articles.php line 14 at Articles->setPublishAtAttribute('2016-05-27') in Model.php line 2860  //这里调用setPublishAtAttributeat Model->setAttribute('publish_at', '2016-05-27') in Model.php line 447 //这里就转变成setAttributeat Model->fill(array('_token' => '', 'title' => '我是第二篇文章', 'content' => '爱的飒飒大', 'publish_at' => '2016-05-27')) in Model.php line 281at Model->__construct(array('_token' => '', 'title' => '我是第二篇文章', 'content' => '爱的飒飒大', 'publish_at' => '2016-05-27')) in Model.php line 569at Model::create(array('_token' => '', 'title' => '我是第二篇文章', 'content' => '爱的飒飒大', 'publish_at' => '2016-05-27')) in ArticlesController.php line 31at ArticlesController->store(object(Request))

queryscope

将原来的硬性写在controller的处理时间的方法进行修改

app/Http/Controllers/ArticlesController.php    public function index(){        $articles = Articles::latest()->where('publish_at','>=',Carbon::now())->get(); //这里通过直接写时间处理方法来实现数据处理        return view('articles.index',compact('articles'));    }

改为:

    public function index(){//        $articles = Articles::latest()->where('publish_at','< =',Carbon::now())->get();                $articles = Articles::latest()->publish()->get();                 //创造一个新的方法,目的是更灵活也让目前的代码更加简洁和容易理解,                //例如这里就是从articles里获取大概是最后一条数据然后过滤publish时间然后获取最终数据的大概意思,不用再看where什么的了        return view('articles.index',compact('articles'));    }

然后在model articles里面添加scope

app/Articles.php    public function scopePublish($query){  //scope语法限制,scope+刚才的publish函数名字(需要驼峰法命名)        $query->where('publish_at','< =',Carbon::now());  //固定是传入一个$query,暂时的理解是一个数据查询结果,然后使用where过滤数据    }

因为是使用的是model articles的实例,scope命名会让laravel会执行一些自动数据查询,所以能够将数据查询结果$query传入,并且处理

科普知识:

latest()返回的是一个builder对象

Builder|Builder latest(string $column = 'created_at')Add an "order by" clause for a timestamp to the query.Parametersstring  $column Return ValueBuilder|Builder

builder对象是一个特殊的数据对象,是laravel的数据库管理的一个对象,一个builder里面包含了很多数据信息,方便直接使用。

alls方法返回的是一个collection对象

static Collection|Model[] all(array|mixed $columns = array('*'))Get all of the models from the database.Parametersarray|mixed $columns    Return ValueCollection|Model[]

这是collection的格式:

Collection {#136 ▼  #items: array:6 [▼    0 => Articles {#137 ▼      #fillable: array:3 [▶]      #connection: null      #table: null      #primaryKey: "id"      #perPage: 15      +incrementing: true      +timestamps: true      #attributes: array:6 [▼        "id" => 6        "title" => "我是第二篇文章"        "content" => "爱的飒飒大"        "publish_at" => "2016-05-27 08:17:29"        "created_at" => "2016-05-21 08:17:29"  //collection里面的数据是数组包含对象,所以方便调用。        "updated_at" => "2016-05-21 08:17:29"      ]      #original: array:6 [▶]      #relations: []      #hidden: []      #visible: []      #appends: []      #guarded: array:1 [▶]      #dates: []      #dateFormat: null      #casts: []      #touches: []      #observables: []      #with: []      #morphClass: null      +exists: true      +wasRecentlyCreated: false    }    1 => Articles {#138 ▶}    2 => Articles {#139 ▶}    3 => Articles {#140 ▶}    4 => Articles {#141 ▶}    5 => Articles {#142 ▶}  ]}

这是builder的格式:

Builder {#128 ▼  #query: Builder {#127 ▼    #connection: MySqlConnection {#123 ▶}    #grammar: MySqlGrammar {#124 ▶}    #processor: MySqlProcessor {#125}    #bindings: array:6 [▶]    +aggregate: null    +columns: null    +distinct: false    +from: "articles"    +joins: null    +wheres: array:1 [▼ //builder里面包含的数据会存在这里,不过不能直接使用,需要使用像get这样的方法来转换数据。      0 => array:5 [▼        "type" => "Basic"        "column" => "publish_at"        "operator" => ">="        "value" => Carbon {#129 ▼          +"date": "2016-05-21 09:08:10.000000"          +"timezone_type": 3          +"timezone": "UTC"        }        "boolean" => "and"      ]    ]    +groups: null    +havings: null    +orders: array:1 [▶]    +limit: null    +offset: null    +unions: null    +unionLimit: null    +unionOffset: null    +unionOrders: null    +lock: null    #backups: []    #bindingBackups: []    #operators: array:26 [▶]    #useWritePdo: false  }  #model: Articles {#121 ▼    #fillable: array:3 [▶]    #connection: null    #table: null    #primaryKey: "id"    #perPage: 15    +incrementing: true    +timestamps: true    #attributes: []    #original: []    #relations: []    #hidden: []    #visible: []    #appends: []    #guarded: array:1 [▶]    #dates: []    #dateFormat: null    #casts: []    #touches: []    #observables: []    #with: []    #morphClass: null    +exists: false    +wasRecentlyCreated: false  }  #eagerLoad: []  #macros: []  #onDelete: null  #passthru: array:11 [▶]  #scopes: []}

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