Question

我正在建立一个调查平台，我需要获得调查的平均答案率。我目前正在做的是检索所有问题，然后将查看时间和回答时间分开。通过计算DB上的平均值而不是循环数千个结果，是否有更高效/更少资源消耗的方法？

这是我现在的工作代码，需要永远：

    $total_showed = 0;
    $total_answered = 0;

    $total_queries = Query::where('client_app_id','=', $app_id)->get();

    foreach ($total_queries as $app_query) {
         $total_showed = $total_showed + $app_query->showed;
         $total_answered = $total_answered + $app_query->answered;
    }
    if ($total_showed > 0) {
        $total_arate = round(($total_answered / $total_showed) * 100, 1);
    } else {
        $total_arate = 0;
    }

Answer 1

当然可以进入Raw SQL：

而不是：

public void Add(int value)
{
    if (root == null)
    {
        root = new Node(value);
        return;
    }
    Node parent = null , 
         res;
    //finding the correct place
    res = Find(value, root, ref parent);

    if (res == null) //probably redunant
    {
        //once found create a node and asign it's parent
        res = new Node(value);
        res.m_parent = parent;
    }
    //EvaluateAVT(res);


}

private Node Find(int value, Node node, ref Node parent,bool justfind = false)
{

    if (node.Data == value && justfind)
    {
        return node;
    }
    if (node.Data >= value)
    {
        if (node.m_left == null)
        {
           parent = node;
           return node.m_left;
        }
        return Find(value,node.m_left,ref parent ,justfind);
    }
    else
    {
        if (node.m_right == null)
        {
            parent = node;
            return node.m_right;
        }
        return Find(value, node.m_right, ref parent, justfind);
    }
}

使用类似的东西：

$total_queries = Query::where('client_app_id','=', $app_id)->get();

Answer 2

试 $total_showed = $total_queries->sum('showed') $total_answered = $total_queries->sum('answered')

因为$ total_queries是一个集合，所以你可以使用它的sum方法见https://laravel.com/docs/5.3/collections#method-sum 我认为这将是有效率的

Answer 3

尝试这个聚合函数avg（）;像这样

$price = DB::table('orders')->where('finalized', 1)
                ->avg('price')

PHP - Laravel - 直接从Eloquent获得平均值而不必循环遍历结果

3 个答案: