yii框架學習(二)

1. 模型
   1. orderby的使用:
      ->orderBy(['addtime'=>SORT_DESC, 'sort'=>SORT_ASC])->all()
   2. 在使用find()查詢的時候, 指定查詢字段:
      find()->select('id, title, content') 指定查詢的字段
   3. 塊賦值, 使用attributes, 好比 $psychological->attributes = $input; 把數組一次性賦值給attributes 屬性, 可是要注意, 要確保模型類中的rules方法, 已經包含了要賦值的字段. 不然attributes 屬性接收不到值. 就不能保存成功
   4. where 做爲查詢條件單獨拿出來的時候, 想使用  <  >  >=  <=  <>  進行範圍查詢的時候, 要怎麼寫?
      

      $where = [
            'and',
            ['<', 'minscore', $score],
            ['>', 'maxscore', $score],
       ];
      //查詢知足minscore<$score而且maxscore>$score 的記錄

   5. yii2中同時鏈接兩個或以上數據庫:(若是在本地開發完,傳到線上服務器, 須要把配置的數據庫的用戶名和密碼改爲線上數據庫的
      )
      1. 在config目錄下web.php文件中的components數組裏配置

         'db2' => [
                     'class' => 'yii\db\Connection',
                     'dsn' => 'mysql:host=localhost;dbname=quickapp',
                     'username' => 'root',
                     'password' => 'root',
                     'charset' => 'utf8',
                 ],

      2. 在繼承ActiveRecord的模型中設置表名,rules等,必需要注意一點, yii默認鏈接的是components裏面的db設置的數據庫, 因此當鏈接其餘數據庫的時候, 就必需要重寫 getDb() 方法, 很簡單

         public static function getDb()
             {
                 return \Yii::$app->db2; //db2就是components裏的db2下標
             }

         OK, 能夠使用了.

   6. 　yii打印SQL語句:

      echo RecycleModel::find()
                  ->alias('r')
                  ->select('r.name as rubbish, c.id, c.name, c.code, c.inc, c.des,c.req')
                  ->leftJoin(['c'=>RecycleCateModel::tableName()], 'r.category_id=c.id')
                  ->where($where)
                  ->orderBy(['modified'=>SORT_DESC])
                  ->limit('10')
                  ->asArray()->createCommand()->getRawSql();exit;

       

   7. 添加數據()

      $usercode = \Yii::$app->db->createCommand()
                  ->batchInsert(UserVoucher::tableName(), ['code', 'cat_id','userId', 'gettime', 'expire'], [
                  [$code['code'], $id, $userId, time(), $code['expire']],
                 ])->execute();      //  \Yii::$app->db  這裏的db, 若是換成db2, 就是往db2數據庫裏插入數據. 

       

   8. 連表查詢分頁

      $count = VoucherCode::find()
          ->alias('v')
          ->leftJoin(['c'=>RubbishCate::tableName()], 'v.cat_id=c.id and v.is_delete=0')
          ->where($where)
          ->count(); //查詢符合連表數據總數
      $p = new Pagination(['totalCount'=>$count, 'pageSize'=>15]);
      $code = VoucherCode::find()
          ->alias('v')
          ->leftJoin(['c'=>RubbishCate::tableName()], 'v.cat_id=c.id and v.is_delete=0')
          ->select('v.*, c.name')
          ->where($where)
          ->offset($p->offset)
          ->limit($p->limit)
          ->asArray()
          ->all(); //查詢數據
      return $this->render('/rubbish-voucher/list', ['code'=>$code, 'pagination'=>$p]);
      //views視圖調用

      <?php echo \yii\widgets\LinkPager::widget([
          'pagination' => $pagination,
          'prevPageLabel' => '上一頁',
          'nextPageLabel' => '下一頁',
          'firstPageLabel' => '首頁',
          'lastPageLabel' => '尾頁',
          'maxButtonCount' => 5,
          'options' => [
              'class' => 'pagination',
          ],
          'prevPageCssClass' => 'page-item',
          'pageCssClass' => "page-item",
          'nextPageCssClass' => 'page-item',
          'firstPageCssClass' => 'page-item',
          'lastPageCssClass' => 'page-item',
          'linkOptions' => [
              'class' => 'page-link',
          ],
          'disabledListItemSubTagOptions' => ['tag' => 'a', 'class' => 'page-link'],
      ])
      ?>

       

   9.  

      條件查詢：

      $status = \Yii::$app->request->get('status', '');   //獲取用戶傳入的條件
      $where = [];
      if($status != ''){         
           $where['status'] = $status;       
      }
      $where['is_delete'] = 0;

       

   10.  

       多對多關聯

       //課程表和用戶表多對多關聯, 課程course模型裏獲取用戶表字段, 中間表爲 user_course, 中間表寫在viaTable()裏
       public function getUser()
           {
               return $this->hasMany(User::className(), ['id'=>'uid'])->viaTable('user_course', ['course_id'=>'id']);
           }
       //或者使用via()
       //獲取關聯表的屬性
       $user = Course::findOne($v['id'])->user;
       //統計有多少人
       $num = count(Course::findOne($v['id'])->user);

        

   11.  

        接口返回分頁數據

       $count = Course::find()->where($where)->count();  //數據總數
       $p = new Pagination(['totalCount'=>$count, 'pageSize'=>$pagesize]);  //實例化分頁類
       $course = Course::find()->select('id, title, pic_url, sections, teacher, fee, free')->where($where)->offset(($page-1)*$pagesize)->limit($p->limit)->all();   //前端傳入第幾頁$page和每頁顯示多少條$pagesize, 主要是offset方法裏的參數怎麼寫

        或者這麼寫

       $course = Course::find()->select('id, title, pic_url, sections, teacher, fee, free')->where($where)->offset(($page-1)*$pagesize)->limit($pagesize)->all();

        

   12.  

       $model->errors; 打印數據驗證過程當中的錯誤信息　
   13. 根據where條件查詢指定字段, 拼接field時候, 若是有重複字段仍然能夠正常查詢的. 而且若是沒有指定where條件, 默認查詢幾個字段

       if(isset($refund_rate))
                   $where['refund_rate'] = $refund_rate;
               if(isset($row_sate_rate))
                   $where['row_sate_rate'] = $row_sate_rate;
               if(isset($film_playnum))
                   $where['film_playnum'] = $film_playnum;
               if(isset($layout_ratio))
                   $where['layout_ratio'] = $layout_ratio;
               if(isset($person_time))
                   $where['person_time'] = $person_time;
               if(isset($date))
                   $where['date'] = $date;
               //設置查詢的指定字段
               $field = '';
               if(isset($where)){
                   $field = implode(',', array_keys($where));
               }
               $field .= ', id, movie_name, split_box_total, synthesize_total, date ';  //多加date 並不會報錯
               $result = TicketMovie::find()->select($field)->where($where)->offset(($page-1)*$pagesize)->limit($pagesize)->asArray()->all();