本文實例講述了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:以下知識點可能有不全面之處,望見諒
NO.1Eloquent ORM簡介
Laravel所自帶的Eloquent ORM是一個優(yōu)美、簡潔的ActiveRecord實現(xiàn),用來實現(xiàn)數(shù)據(jù)庫操作
每個數(shù)據(jù)表都有與之相對應的“模型(Model)”用于和數(shù)據(jù)交互
NO.2模型的建立
最基礎的模型代碼如下:
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),那么他會報錯,而find若是沒有查到該函數(shù),只會彈出一個null
4.查詢構造器的使用
namespace App\Http\Controllers;
use App\Student;
use Illuminate\Support\Facades\DB;
class StudentController extends Controller
{
public function orm1()
{
$students = Student::get();
dd($students);
}
}
他會得到一個完整的數(shù)據(jù)信息,和原本的意義沒有區(qū)別
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id大于一的時候,獲取一個最大值的age
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);
}
}
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
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
更多關于Laravel相關內容感興趣的讀者可查看本站專題:《Laravel框架入門與進階教程》、《php優(yōu)秀開發(fā)框架總結》、《php面向對象程序設計入門教程》、《php+mysql數(shù)據(jù)庫操作入門教程》及《php常見數(shù)據(jù)庫操作技巧匯總》
希望本文所述對大家基于Laravel框架的PHP程序設計有所幫助。
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