tp5 高效率隨機抽取數據(不重複)

public function getRandTable(){
    $num = 5;    //需要抽取的默認條數
    $table = ‘t_marclog‘;    //需要抽取的數據表
    $countcus = Db::name($table)->count();    //獲取總記錄數
    $min = Db::name($table)->min(‘id‘);    //統計某個字段最小數據
    if($countcus < $num){$num = $countcus;}
    $i = 1;
    $flag = 0;
    $ary = array();
    while($i<=$num){
        $rundnum = rand($min, $countcus);//抽取隨機數
        if($flag != $rundnum){
            //過濾重複 
            if(!in_array($rundnum,$ary)){
                $ary[] = $rundnum;
                $flag = $rundnum;
            }else{
                $i--;
            }
            $i++;
        }
    }
    $list = Db::name($table)->where(‘id‘,‘in‘,$ary,‘or‘)->select();
    $this->assign(‘list‘, $list);
}