解析:使用php mongodb扩展时 需要注意的事项

最近在使用php的mongo 扩展进行数据统计计算，其中有一个时间戳字段，由于精确到了毫秒，长度有13位，但由于开始的时候是以字符串的形式存储：

{ "_id" : objectid("504eea97e4b023cf38e34039"), "in_ts" : numberlong("1347349143699"), "log" : { "guid" : "4d1f3079-7507-f4b0-e7af-5432d5d8229d", "p" : "view_prop_yeppage_zheng", "cid" : "11", "url" : "http://shanghai.haozu.com/rental/broker/n/10481780", "rfpn" : "listing_v2_indexpage_all", "site" : "haozu", "agent" : "mozilla/4.0 (compatible; msie 6.0; windows nt 5.1; sv1)", "stamp" : "1347349162159", "cip" : "116.226.70.44", "referer" : "http://shanghai.haozu.com/shop/1464934/", "cstamp" : "1347349323125", "sessid" : "fa798056-f9e7-f961-41e0-cc95c850fa47", "uguid" : "c00ff55b-3d3d-4b31-4318-12345b0dbe64", "pn" : "view_prop_yeppage_zheng", "cstparam" : { "proid" : numberlong(10481780), "brokerid" : "326792", "tradetype" : "2", "usertype" : "0", "channel" : "site", "entry" : "1", "commid" : "1666" } }, "out_ts" : numberlong("1347349466083"), "rule" : 0, "status" : "ok", "txid" : 0 }

后来改成数字格式：

{ "_id" : objectid("504eea97e4b023cf38e34039"), "in_ts" : numberlong("1347349143699"), "log" : { "guid" : "4d1f3079-7507-f4b0-e7af-5432d5d8229d", "p" : "view_prop_yeppage_zheng", "cid" : "11", "url" : "http://shanghai.haozu.com/rental/broker/n/10481780", "rfpn" : "listing_v2_indexpage_all", "site" : "haozu", "agent" : "mozilla/4.0 (compatible; msie 6.0; windows nt 5.1; sv1)", "stamp" : numberlong("1347349162159"), "cip" : "116.226.70.44", "referer" : "http://shanghai.haozu.com/shop/1464934/", "cstamp" : "1347349323125", "sessid" : "fa798056-f9e7-f961-41e0-cc95c850fa47", "uguid" : "c00ff55b-3d3d-4b31-4318-12345b0dbe64", "pn" : "view_prop_yeppage_zheng", "cstparam" : { "proid" : numberlong(10481780), "brokerid" : "326792", "tradetype" : "2", "usertype" : "0", "channel" : "site", "entry" : "1", "commid" : "1666" } }, "out_ts" : numberlong("1347349466083"), "rule" : 0, "status" : "ok", "txid" : 0 }

为字符串时，使用下面的查询是正常的

$query = array ('log.stamp' => array ('$gte' => ‘1347346800000', '$lt' => ‘1347350400000'));

但是改为数字后，使用下面的查询，死活没有结果，但是直接在mongo客户端直接查询是有结果的：

db.haozu_success.find({'log.stamp':{$gte:1347346800000,$lt:1347350400000}})

php手册上也是这么个用法：

$query = array ('log.stamp' => array ('$gte' => 1347346800000, '$lt' => 1347350400000));

花了好大一会找原因，开始时怀疑是php扩展的bug导致，经过一番思考。突然想到可能是类型问题导致，发现手册上有types 介绍，所以正确的用法如下：

$query = array ('log.stamp' => array ('$gte' => new mongoint64($time_range['start']), '$lt' => new mongoint64($time_range['end'])));

另外，在使用mapreduce进行数据统计时，为了防止cursor出现超时异常，还需要设置一下超时时间

$map = new mongocode ( '
                function(){
                    var prop_id=this.log.cstparam.proid;
                    var key=this.log.site+prop_id
                    emit(key,{"channel":this.log.site,"prop_id":prop_id,"count":1});
                }
                ' );
        $reduce = new mongocode ( '
                function(key,emits){
                    var total=0;
                    for(var i in emits){
                        total+=emits[i].count;
                    }
                    return {"channel":emits[0].channel,"prop_id":eval(emits[0].prop_id),"count":total};
                }
                ' );
$this->mongo_db->command ( array ('mapreduce' => $collection_name, 'map' => $map, 'reduce' => $reduce, 'out' => $tmp_result, 'query' => $query),array('timeout'=>self::mongo_cursor_timeout) );