php – Mongo Map首先减少

$mongo->dbname->visits

{"url": "www.example.com","type": "a","refer": {"external": true,"domain": "twitter.com","url": "http://www.twitter.com/page"},"page": "1235","user": "1232","time": 1234567890}

{"url": "www.example.com","type": "b","page": "745","time": 1234567890,"tags": {"a","b","c"}}

好的,我想出了我认为可以做你想要的东西.注意,这可能无法正常工作,因为我不是100％确定您的模式(考虑到您的示例显示参考可用类型a,但不是b(我不知道这是否是一个遗漏,或什么考虑你想要无论如何,这里是我想出的：

地图功能：

function() {
    var obj = {
        "types": {},"tags": {},}
    obj.types[this.type] = 1;
    if (this.tags) {
        for (var tag in this.tags) {
            obj.tags[this.tags[tag]] = 1;
        }
    }
    emit(this.refer.url,obj);
}

减少功能：

function(key,values) {
    var obj = {
        "types": {},}
    for (var i = 0; i < values.length; i++) {
        for (var type in values[i].types) {
            if (!type in obj.types) {
                obj.types[type] = 0;
            }
            obj.types[type] += values[i].types[type];
        }
        for (var tag in values[i].tags) {
            if (!tag in obj.tags) {
                obj.tags[tag] = 0;
            }
            obj.tags[tag] += values[i].tags[tag];
        }
    }
    return obj;
}

所以基本上,它是如何工作的. Map函数使用refer.url的键(我根据您的描述猜测).所以最终结果将看起来像一个数组,_id等于refer.url(它基于url进行分组).然后,它创建一个对象,其下有两个对象(类型和标签).对象的原因是map和reduce可以发出相同的格式对象.除此之外,我认为它应该是相对自我解释(如果你不明白,我可以尝试解释更多)…

所以让我们在PHP中实现这一点(假设$map和$reduce是上面包含的字符串,它们是简洁的)：

$mapFunc = new MongoCode($map);
$reduceFunc = new MongoCode($reduce);
$query = array(
    'time' => array('$gte' => time() - (60*60*60*24*30)),'refer.external' => true
);
$collection = 'visits';
$command = array(
    'mapreduce' => $collection,'map' => $mapFunc,'reduce' => $reduceFunc,'query' => $query,);

$statsInfo = $db->command($command);

$statsCollection = $db->selectCollection($sales['result']);

$stats = $statsCollection->find();

foreach ($stats as $stat) {
    echo $stats['_id'] .' Visited ';
    foreach ($stats['value']['types'] as $type => $times) {
        echo "Type $type $times Times,";
    }
    foreach ($stats['value']['tags'] as $tag => $times) {
        echo "Tag $tag $times Times,";
    }
    echo "\n";
}

注意,我还没有测试过这个.这正是我根据我对你的架构的理解而得出的,从我对Mongo及其Map-Reduce实现的理解…