Laravel框架Eloquent ORM简介、模型建立及查询数据操作详解

本文实例讲述了laravel框架eloquent orm简介、模型建立及查询数据操作。分享给大家供大家参考，具体如下：

注：以下知识点可能有不全面之处，望见谅

no.1eloquent or上能m简介

laravel所自带的eloquent orm是一个优美、简洁的activerecord实现，用来实现数据库操作
每个数据表都有与之相对应的“模型（model）”用于和数据交互

no.2模型的建立

最基础的模型代码如下:

namespace app;u illuminate\databa\eloquent\model;class student extends model{ //指定表名 protected $table = 'student'; //指定id protected $primarykey = 'id';}

将他创建于app目录下，命名为student.php

no.3查询数据

首先在查活动广告宣传语询之前，我先让你们看一下我的数据库

数据如上，然后查询

1.all方式

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {      $students = student::all();      dd($students); }}

显示数据库里的所有数据

2.find方式

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {      $尿道炎怎么治students = student::find(1);      dd($students); }}

查找指定数据

3.findorfail方式

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {      $students = student::极坐标方程公式findorfail(1);      dd($students); }}

如果他没查到指定的数据，那么他会报错，而find若是没有查到该函数，只会弹出一个null

4.查询构造器的使用

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {      $students = student::get();      dd($students); }}

他会得到一个完整的数据信息，和原本的意义没有区别

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {     $student = student::where('id','>',1)     ->orderby('age','desc')     ->first();     dd($student); }}

当id大于一的时候，获取一个最大值的age

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {     $student = student::where('id','>',1)     ->get();     dd($student); }}

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {     $student = student::chunck(2,function($student){  var_dump($student); }); }}

5.聚合函数的使用

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {     $student = student::count();     dd($student); }}

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {     $student = student::max('age');     dd($student); }}

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public fun非主流歌ction orm1()  {     $student = student::min('age');     dd($student); }}

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {     $student = student::avg('age');     dd($student); }}

代码如下:

namespace app\http\controllers;u app\student;u illuminate\support\facades\db;class studentcontroller extends controller{ public function orm1()  {     $student = student::sum('age');     dd($student); }}