YII2-基础

た入场券 2022-05-28 07:58 274阅读 0赞

# 学习内容：YII2-基础 #

## 1、命名空间 ##

## 2、创建控制器 ##

1- 创建控制器：文件名：TestController  
2- 访问的路径：[http://www.backend.com/test/index][http_www.backend.com_test_index]

<?php
    namespace backend\controllers;
    use yii\web\Controller;
    class TestController extends Controller
    {
        public function actionIndex()
        {
           echo '11';
        }
    }

## 3、请求方式 ##

### 1、请求参数 ###

$request = Yii::$app->request;
    $get = $request->get(); 
    $id = $request->get('id');   
    $id = $request->get('id', 1);   
    $post = $request->post(); 
    $name = $request->post('name');  
    $name = $request->post('name', '');

### 2、restfull请求 \#\#\# ###

//返回所有参数
    $params = $request->bodyParams;
    //返回参数的id
    $param = $request->getBodyParam('id');

### 3、请求方法 ###

if ($request->isAjax) { /* 该请求是一个 AJAX 请求 */ }
    if ($request->isGet)  { /* 请求方法是 GET */ }
    if ($request->isPost) { /* 请求方法是 POST */ }
    if ($request->isPut)  { /* 请求方法是 PUT */ }

### 4、请求头 ###

$headers = Yii::$app->response->headers;
    // 增加一个 Pragma 头，已存在的Pragma 头不会被覆盖。
    $headers->add('Pragma', 'no-cache');
    // 设置一个Pragma 头. 任何已存在的Pragma 头都会被丢弃
    $headers->set('Pragma', 'no-cache');
    // 删除Pragma 头并返回删除的Pragma 头的值到数组
    $values = $headers->remove('Pragma');

### 5、请求的客户端信息 ###

$userHost = Yii::$app->request->userHost;
    $userIP = Yii::$app->request->userIP;

## 4、响应 ##

$res = Yii::$app->response;
    //返回状态码
    $res -> statusCode = 404;
    //增加一个pragma头
    $res->headers->add('Pragma','no-cache');
    //设置一个pragma头
    $res->headers->set('Pragma','max-age=5');
    //删除pragma头
    $res->headers->remove('Pragma');
    //跳转
    $res->headers->add('location','http://www.baidu.com');
    //跳转
    $res->redirect('http://www.baidu.com',302);
    //文件下载
    $res->headers->add('content-disposition','attachment;filename="a.jpg" ');
    $res->sendFile('./robots.txt');

## 5、Session ##

$session = Yii::$app->session;
    检查是否开启
    if($session->isActive){
        echo 'session';
    }
    
    设置一个session
    $session->set('user','zhangsan');
    获取一个session
    echo $session->get('user');
    删除session
    $session->remove('user');
    
    $session['user']  ='张三';
    echo $session['user'];
    unset($session['user']);

## 6、cookie ##

$cookies = Yii::$app->response->cookies;
    $cookie_data = array('name'=>'user','value'=>'zhangsan');
    $cookies->add(new Cookie($cookie_data));
    $cookies->remove('user');
    
    $cookies = Yii::$app->request->cookies;
    echo $cookies->getValue('user');
    echo $cookies->getValue('users',20);
    
    $hello_str = 'hello world！<script>alert3;</script>';
    $test_str = array(1,2);
    $data = [];
    
    $data['view_hello_str'] = $hello_str;
    $data['view_test_str'] = $test_str;
    
    return $this->render('index',$data);
    return $this->render('about');

## 7、视图的创建 ##

文件位置：asset文件夹下，test文件夹、view.php文件  
render：加载父类模板  
renderPartial：不加载父类模板

public function actionView($id)
    {
        return $this->render('view', [
            'model' => $this->findModel($id),
        ]);
    }

## 8、缓存 ##

获取缓存组件
    $cache = Yii::$app->cache;
    
    往缓存中写数据
    $cache ->add('key1','hello world');
    $cache ->add('key1','hello world2');
    
    修改缓存  可以设置
    $cache->set('key1','hello world');
    $cache->set('key1','hello world2');
    
    读取缓存
     $data = $cache ->get('key1');
    
    删除数据
     $data = $cache->delete('key1');
    
    清空数据
    $cache->flush();
    $data = $cache->get('key1');
    
    缓存有效期
     $cache->add('key','hello world',5);
    $cache->set('key','hello world',5);
    echo $cache->get('key');
    var_dump($data);

## 9、模型的创建 ##

文件位置：models  
文件名：Test.php

<?php
    namespace backend\models;
    use yii\db\ActiveRecord;
    
    class Test extends ActiveRecord
    {
    
    }

## 10、活动创建 ##

public function actionIndexss()
    {
        //查询数据
        $sql = " select * from test where id =1";
        $model = new Test;
        $res = $model::findBySql($sql)->all();
    
        //id = 1
        $res = $model::find()->where(['id'=>1])->all();
        //id > 0
        $res = $model::find()->where(['>','id',0])->all();
        //id >= 1 且 id <= 2
         $res = $model::find()->where(['between','id',1,2])->all();
        //title like '%title1%'
        $res = $model::find()->where(['like', 'title', 'title'])->all();
    
        //查询结果转为数组  将数组转为对象  内存占有量比较高  需要转为数组 asArray()
        //$res = $model::find()->where(['between','id',1,2])->asArray()->all();
    
        //批量查询  //每次拿多少 batch
        /*oreach ($model::find()->batch(1) as $tests){
            print_r(count($tests));
    
        //删除数据
        $res = $model::find()->where(['id'=>1])->all();
        $res[0] ->delete();
        $model::deleteAll('id>:id',array(':id'=>0));
    
        //增加数据
        $model->id = 4;
        $model->title = 'title3';
        $model->validate();
        if($model->hasErrors()){
        echo 'data is error';
        die;
        $model->save();
    
        //修改数据
        $res = $model::find()->where(['id'=>4])->one();
        $res->title = 'title4';
        $res->save();
        print_r($res);
    }

## 11、关联关系 ##

分别新建两个模型 customer.php order.php

### 1、Customer模型 ###

<?php
    namespace common\models;
    use yii\db\ActiveRecord;
    class Customer extends ActiveRecord
    {
        public function getOrders()
        {
            //根据客户找订单 一个客户多个订单 客户的id  对应  订单id
            return $this->hasMany(Order::className(),['customer_id'=>'id'])->asArray();
        }
    }

### 2、Order模型 ###

<?php
    namespace common\models;
    use yii\db\ActiveRecord;
    
    class Order extends ActiveRecord
    {
        //根据订单查找客户  一个订单对应一个客户
        public function getCustomer()
        {
            return $this->hasOne(Customer::className(),['id'=>'customer_id'])->asArray();
        }
    }

### 3、控制器 ###

//根据客户查找出对应的订单
    $customer = Customer::find()->where(['name'=>'li'])->one();
    $data = $customer->orders;
    
    //根据订单找客户
    $order_data = Order::find()->where(['id'=>1])->one();
    $user = $order_data->customer;
    print_r($user);

### 12、关联查询的优化 ###

//关联查询的多次查询  首先select * from customer  然后每次遍历再查一次
    $customers = Customer::find()->all();
    foreach ($customers as $customer){
        $orderes = $customer ->orders;
    }
    
    //优化 首先 select * from customer  然后select * from order where customer_id in ();
    $customers = Customer::find()->with('orders')->all();
    foreach ($customers as $customer){
        $orderes = $customer ->orders;
    }

[http_www.backend.com_test_index]: http://www.backend.com/test/index