laravel构造器及模型

laravel构造器及模型

home.php

<?php
namespace App\Http\Controllers;
use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\DB;
use App\Article;
// 后台主页
class Home extends Controller{
    // 查询多条记录
    // get()
    // get()->all()数组
    public function list(){
        $res = DB::table('article')->get()->all();
        echo '<pre>';
        print_r($res);
    }
    // 指定查询字段select
    // 条件where('cate_id','=',5),   '='可省略
    // and使用where()->where()
    // or使用where()->orWhere()
    public function selectlist(){
        $res = DB::table('article')->select('cate_id as cid','title')->where('cate_id',5)->get()->all();
        echo '<pre>';
        print_r($res);
    }
    // like查询
    // tosql可查看sql语句，？是点位符
    public function likes(){
        $res = DB::table('article')->where('title','like','%5%')->where('cate_id',5)->tosql();
        echo '<pre>';
        print_r($res);
    }
    // where in查询
    public function wherein(){
        $res = DB::table('article')->whereIn('cate_id',[1,5,7])->get()->all();
        echo '<pre>';
        print_r($res);
        print_r($res[0]->title);
    }
    // 连表查询
    public function joins(){
        $res = DB::table('article')->join('users','users.id','=','article.uid')->select('article.title','users.username as nickname')->get()->all();
        echo '<pre>';
        print_r($res);
    }
    // 平均avg,最大max,最小min,计数count
    public function pvs(){
        $res = DB::table('article')->avg('pv');
        //$res = DB::table('article')->max('pv');
        //$res = DB::table('article')->min('pv');
        //$res = DB::table('article')->count();
        $res = (int)$res;
        echo '<pre>';
        print_r($res);
    }
    // 增加数据
    public function insert2(){
        $data = [];
        $data[]= array('uid'=>2,'cate_id'=>7,'title'=>'insert测试5','pv'=>0);
        $data[]= array('uid'=>1,'cate_id'=>6,'title'=>'insert测试4','pv'=>0);
        $res = DB::table('article')->insert($data);
        echo '<pre>';
        var_dump($res);
    }
    // 增加数据并获取ID
    public function insert3(){
        $data= array('uid'=>1,'cate_id'=>8,'title'=>'insert测试7','pv'=>0);
        $res = DB::table('article')->insertGetId($data);
        echo '<pre>';
        var_dump($res);
    }
    // 修改数据
    public function update2(){
        $res = DB::table('article')->whereIn('id',[10,11])->update(array('title'=>'update测试'));
        echo '<pre>';
        var_dump($res);
    }
    //删除
    public function delete2(){
        $res = DB::table('article')->whereIn('id',[10,12])->delete();
        echo '<pre>';
        var_dump($res);
    }
    //模型
    public function mymodels(Article $article){
        $res = $article->get()->toArray();
        echo '<pre>';
        print_r($res);
    }
}

创建模型（article.php）

在powershell中
H:\phpstudy_pro\www\laravel7> php artisan make:model Article

article.php

<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Article extends Model
{
    //指定表名,不然默认找名字为“articles”的表
    protected $table= 'article';
}