解析:使用php mongodb扩展时需要注意的事项

时间：2018-12-30分类：PHP作者：编程之家

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：
<div class="codetitle"><a style="CURSOR: pointer" data="1252" class="copybut" id="copybut1252" onclick="doCopy('code1252')"> 代码如下:

<div class="codebody" id="code1252">
{ "_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：
<div class="codetitle"><a style="CURSOR: pointer" data="92966" class="copybut" id="copybut92966" onclick="doCopy('code92966')"> 代码如下:

<div class="codebody" id="code92966">
{ "_id" : ObjectId("504eea97e4b023cf38e34039"),"stamp" : NumberLong("1347349162159"),"txid" : 0 }

为字符串时，使用下面的查询是正常的
<div class="codetitle"><a style="CURSOR: pointer" data="70940" class="copybut" id="copybut70940" onclick="doCopy('code70940')"> 代码如下:

<div class="codebody" id="code70940">
$query = array ('log.stamp' => array ('$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：
<div class="codetitle"><a style="CURSOR: pointer" data="10461" class="copybut" id="copybut10461" onclick="doCopy('code10461')"> 代码如下:

<div class="codebody" id="code10461">
db.haozu_success.find({'log.stamp':{$gte:1347346800000,$lt:1347350400000}})

PHP手册上也是这么个用法：
<div class="codetitle"><a style="CURSOR: pointer" data="91898" class="copybut" id="copybut91898" onclick="doCopy('code91898')"> 代码如下:<div class="codebody" id="code91898">
$query = array ('log.stamp' => array ('$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：
<div class="codetitle"><a style="CURSOR: pointer" data="74144" class="copybut" id="copybut74144" onclick="doCopy('code74144')"> 代码如下:<div class="codebody" id="code74144">
$query = array ('log.stamp' => array ('$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
<div class="codetitle"><a style="CURSOR: pointer" data="847" class="copybut" id="copybut847" onclick="doCopy('code847')"> 代码如下:<div class="codebody" id="code847">
$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) );

mongodb扩展