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Laravel框架Eloquent ORM簡介、模型建立及查詢數(shù)據(jù)操作詳解

更新時(shí)間：2019年12月04日 11:28:19 作者：陳柴Rarin

這篇文章主要介紹了Laravel框架Eloquent ORM簡介、模型建立及查詢數(shù)據(jù)操作,結(jié)合實(shí)例形式詳細(xì)分析了laravel框架Eloquent ORM基本概念、原理、模型建立及數(shù)據(jù)查詢等相關(guān)使用技巧,需要的朋友可以參考下

本文實(shí)例講述了Laravel框架Eloquent ORM簡介、模型建立及查詢數(shù)據(jù)操作。分享給大家供大家參考，具體如下：

注：以下知識(shí)點(diǎn)可能有不全面之處，望見諒

NO.1Eloquent ORM簡介

Laravel所自帶的Eloquent ORM是一個(gè)優(yōu)美、簡潔的ActiveRecord實(shí)現(xiàn)，用來實(shí)現(xiàn)數(shù)據(jù)庫操作
每個(gè)數(shù)據(jù)表都有與之相對應(yīng)的“模型（Model）”用于和數(shù)據(jù)交互

NO.2模型的建立

最基礎(chǔ)的模型代碼如下:

namespace App;
use Illuminate\Database\Eloquent\Model;
class Student extends Model
{
 //指定表名
 protected $table = 'student';
 //指定id
 protected $primaryKey = 'id';
}

將他創(chuàng)建于app目錄下，命名為Student.php

NO.3查詢數(shù)據(jù)

首先在查詢之前，我先讓你們看一下我的數(shù)據(jù)庫

數(shù)據(jù)如上，然后查詢

1.all方式

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
      $students = Student::all();
      dd($students);
 }
}

顯示數(shù)據(jù)庫里的所有數(shù)據(jù)

2.find方式

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
      $students = Student::find(1);
      dd($students);
 }
}

查找指定數(shù)據(jù)

3.findOrFail方式

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
      $students = Student::findOrFail(1);
      dd($students);
 }
}

如果他沒查到指定的數(shù)據(jù)，那么他會(huì)報(bào)錯(cuò)，而find若是沒有查到該函數(shù)，只會(huì)彈出一個(gè)null

4.查詢構(gòu)造器的使用

1.get方式使用

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
      $students = Student::get();
      dd($students);
 }
}

他會(huì)得到一個(gè)完整的數(shù)據(jù)信息，和原本的意義沒有區(qū)別

2.first方式使用

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
     $student = Student::where('id','>',1)
     ->orderBy('age','desc')
     ->first();
     dd($student);
 }
}

當(dāng)id大于一的時(shí)候，獲取一個(gè)最大值的age

3.where方式使用

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
     $student = Student::where('id','>',1)
     ->get();
     dd($student);
 }
}

4.chunk方式使用

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
     $student = Student::chunck(2,function($student){
  var_dump($student);
 });
 }
}

5.聚合函數(shù)的使用

1.count函數(shù)

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
     $student = Student::count();
     dd($student);
 }
}

2.max函數(shù)

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
     $student = Student::max('age');
     dd($student);
 }
}

3.min函數(shù)

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
     $student = Student::min('age');
     dd($student);
 }
}

4.avg函數(shù)

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
     $student = Student::avg('age');
     dd($student);
 }
}

5.sum函數(shù)

代碼如下:

namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
 public function orm1()
  {
     $student = Student::sum('age');
     dd($student);
 }
}

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希望本文所述對大家基于Laravel框架的PHP程序設(shè)計(jì)有所幫助。

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