Laravel 链式调用增删改查

控制器  home.php
<?php
namespace App\Http\Controllers;
use Illuminate\Support\Facades\DB;
use Illuminate\Http\Request;
class Home extends Controller
{
    //查询多条记录
    public function list(){
        // echo '<pre>';
        $res=DB::table('article')->get()->all();
        // print_r($res);
        return view('testobject',['result'=>$res]);
    }
    //查询多条记录,部分字段
    public function list2(){
        echo '<pre>';
        $res=DB::table('article')->select('cate_id as CID','title as 标题')->where('cate_id','>',4)->get()->all();
        print_r($res);
    }
     //like 查询
     public function likes(){
        // $res=DB::table('article')->where("title",'like','%版本%')->where('id',4)->get()->all();
        $res=DB::table('article')->where("cate_id",4)->orWhere('cate_id',3)->get()->all();
        return view('testobject',['result'=>$res]);
    }
    //where in  查询
    public function wherein(){        
        $res=DB::table('article')->whereIn("id",[1,2,5])->get()->all();
        // $res=DB::table('article')->whereIn("id",[1,2,5])->tosql();
        // print($res);
        return view('testobject',['result'=>$res]);
    }
    //join 连表查询
    public function joins(){
        // $res=DB::table('article')->join('users','users.id','=','article.uid')->get()->all();
        $res=DB::table('article')->join('users','users.id','=','article.uid')
        ->select('article.id','article.uid','article.cate_id','users.name as nickname','article.title')
        ->get()->all();
        echo '<pre>';
        print_r($res);
    }
    //聚合 查询
    public function pvs(){
        // $res=DB::table('article')->get()->all();
        // //原生计算平均值
        // $avg=0;
        // foreach ($res as $key=>$value){
        //     $avg+=$value->pv;
        // }
        // $avg=$avg/count($res);
        // echo '<pre>';
        // print_r($avg);
        $res=DB::table('article')->avg('pv');
        // $res=DB::table('article')->max('pv');
        // $res=DB::table('article')->min('pv');
        // $res=DB::table('article')->sum('pv');
        // $res=DB::table('article')->count();
        $res=(int)$res;
        print_r($res);
    }
    //增加数据
    public function insert2(){
        $item1=['uid'=>1,'cate_id'=>5,'title'=>'测试插入多条insert语句','pv'=>200];
        $item2=['uid'=>2,'cate_id'=>3,'title'=>'测试插入多条insert语句','pv'=>100];
        $data[]=$item1;
        $data[]=$item2;
        $res=DB::table('article')->insert($data);
        var_dump($res);
    }
    //增加数据并返回主键
    public function insert3(){
        $item=['uid'=>2,'cate_id'=>3,'title'=>'测试插入insert语句并返回id值','pv'=>50];
        $res=DB::table('article')->insertGetId($item);
        var_dump($res);
    }
    //修改数据
    public function update2(){
        $res=DB::table('article')->whereIn('id',[8,10])->update(array('title'=>'updta测试'));
        var_dump($res);
    }
    //删除数据
    public function delete2(){
        $res=DB::table('article')->where('id',9)->delete();
        var_dump($res);
    }
}

路由 web.php
<?php
use Illuminate\Support\Facades\Route;
/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/
Route::get('/', function () {
    echo date("Y-m-d H:i:s");
    return view('welcome');
});
//查询多条记录
Route::get('/dblist','home@list');
//查询多条记录，部分字段
Route::get('/dblist2','home@list2');
//like查询
Route::get('/dblikes','home@likes');
//where in 查询
Route::get('/dbwherein','home@wherein');
//join 连表 查询
Route::get('/dbjoins','home@joins');
// 聚合 计算查询
Route::get('/dbpvs','home@pvs');
//增加数据
Route::get('/dbinsert2','home@insert2');
//增加数据并返回主键
Route::get('/dbinsert3','home@insert3');
//修改数据
Route::get('/dbupdate2','home@update2');
//删除数据
Route::get('/dbdelete2','home@delete2');

视图  testobject.blade.php
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>数据库查询2</title>
    <link rel="stylesheet" href="/layui/css/layui.css" />
    <script src="/layui/layui.js"></script>
</head>
<body>
    <!-- <?php 
    echo "<pre>";
    print_r($result);?> -->
    <table class="layui-table">
        <thead>
            <tr>
                <td>ID</td>
                <td>CATE_ID</td>
                <td>标题</td>
            </tr>
        </thead>
        <tbody>
            <?php foreach($result as $val){?>
            <tr>
              <td><?php echo $val->id?></td>
              <td><?php echo $val->cate_id?></td>
              <td><?php echo $val->title?></td>
            </tr>
            <?php }?>
        </tbody>
    </table>
</body>
</html>

效果图如下：

总结：
1、Laravel 框架链式语法容易理解便于记忆，关键词大多与php原生语法一致。开发效率较高。
2、条件语句中尽量用 “=”，效率高；避免用“>”或“<”,大数据量时速度很慢。在必须使用一个范围内查询时，推荐使用whereIn(‘字段’,[…])。
3、all()得出的数组，元素值是对象，可以通过对象->属性名调用；也可以通过array()将其转为数组，利用数组[‘键名’]调用。

批改老师：