yii2 查询数据库语法

        $query0 = ImGroupUser::find()->where(['gid'=>'56680dfc60b215d62104a4d8'])->select('user_client_id')->all();//AR
        $query1=ImGroupUser::findAll(['gid'=>'56680dfc60b215d62104a4d8']);//AR
        $query2=ImGroupUser::findBySql("select user_client_id from im_group_user where gid='56680dfc60b215d62104a4d8'")->all();//AR
        $query3=ImGroupUser::find()->where(['gid'=>'56680dfc60b215d62104a4d8'])->select('user_client_id')->asArray()->all();//Array
        $query = new yiidbQuery();
        $query4 = $query
            ->select(['user_client_id'])
            ->from(['im_group_user'])
            ->where(['gid'=>'56680dfc60b215d62104a4d8'])
            ->all();//Array
        $arr=[];
        foreach($query4 as $key=>$value){
//            $arr[]=$value->user_client_id;
            $arr[]=$value['user_client_id'];
        }
        var_dump($arr);

AR查询结果默认为AR单条数据的对象，返回AR对象，用13行取对象结果集，返回Array对象用14行取结果集 注意query4查询结果为数组对象

 $res = ImGroupUser::updateAll(['flag'=>0],['gid'=>$gid,'flag'=>1]);

更新数据库字段值。（将表中所有gid为$gid并且 flag=1的列的flag设为0）

有的时候查询过程较为复杂，使用框架查询效率低下，可以直接使用sql查询：

      $sql="select c_user.client_id,c_user.bapp_broker_id from c_user
              where c_user.client_id!=''
              and c_user.bapp_broker_id!='{$g32}'
              and c_user.id in(select c_user_id from trade_fund_account where cust_id is not null and update_time between  date_sub(now(),interval 10 minute) and now() order by update_time desc)";
        $res=Yii::$app->db->createCommand()->setSql($sql)->queryAll();

Yii查询sql也可以这样写

 $res=Yii::$app->db->createCommand($sql)->queryAll();