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 ORM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
namespace App;use IlluminateDatabaseEloquentModel;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
namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;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
namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $students = Student::find(1); dd($students); }}查找指定数据
3.findOrFail方式
namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $students = Student::findOrFail(1); dd($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
1.get方式使用namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;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
2.first方式使用namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;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
3.where方式使用namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $student = Student::where('id','>',1) ->get(); dd($student); }} 4.chunk方式使用namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $student = Student::chunck(2,function($student){ var_dump($student); }); }}5.聚合函数的使用
1.count函数namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $student = Student::count(); dd($student); }} 2.max函数namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $student = Student::max('age'); dd($student); }} 3.min函数namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $student = Student::min('age'); dd($student); }} 4.avg函数namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $student = Student::avg('age'); dd($student); }} 5.sum函数namespace AppHttpControllers;use AppStudent;use IlluminateSupportFacadesDB;class StudentController extends Controller{ public function orm1() { $student = Student::sum('age'); dd($student); }}更多关于Laravel相关内容感兴趣的读者可查看本站专题：《Laravel框架入门与进阶教程》、《php优秀开发框架总结》、《php面向对象程序设计入门教程》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》
希望本文所述对大家基于Laravel框架的PHP程序设计有所帮助。
