![](/img/trans.png)
[英]get all data in a mongo collection into a text file using javascript
[英]Querying data from Mongo collection using javascript
这是我第一次将mongo用于流星项目,这是为了帮助一群用户协作阅读圣经。 集合的数据结构如下:
//collection is named as 'logs'
[
{
_id: someObjectId,
startPage: 1,
finishPage: 4,
status: 'in progress',
userId: someUserId1
},
{
_id: someObjectId,
startPage: 5,
finishPage: 10,
status: 'done',
userId: someUserId2
}
//.... and so on and normally two users wont read the same page.
]
我正在尝试找出以下几点:
现在由于我对mongo的了解有限,所以我被困在这一点上。 我一直在研究各种解决方案,但不确定哪一种是合适的:
例如
[
{
page: 1,
inProgress: 0, //users would normally not read the same page twice but they may
done: 1
},
{
page: 2,
inProgress: 1, //users would normally not read the same page twice but they may
done: 0
}
]
如果有人可以对此做一些更深入的了解,我将不胜感激。 这可能很明显,但是我发现它有点困难。 谢谢。
我会尝试根据您要实现的用途对文档进行建模,如果将日志分成仅读取的页面,则可以进行简单的分组依据。
假设我们将您的模型更改为以下内容:
[{
_id: new ObjectId(),
pageNumber: 1,
status: 'in progress',
userId: 1
},
{
_id: new ObjectId(),
pageNumber: 2,
status: 'in progress',
userId: 1
},
{
_id: new ObjectId(),
pageNumber: 3,
status: 'in progress',
userId: 1
},
{
_id: new ObjectId(),
pageNumber: 4,
status: 'in progress',
userId: 1
},
{
_id: new ObjectId(),
pageNumber: 5,
status: 'in progress',
userId: 1
},
{
_id: new ObjectId(),
pageNumber: 6,
status: 'done',
userId: 2
},
{
_id: new ObjectId(),
pageNumber: 7,
status: 'done',
userId: 2
},
{
_id: new ObjectId(),
pageNumber: 8,
status: 'done',
userId: 2
},
{
_id: new ObjectId(),
pageNumber: 9,
status: 'done',
userId: 2
},
{
_id: new ObjectId(),
pageNumber: 10,
status: 'done',
userId: 2
},
{
_id: new ObjectId(),
pageNumber: 9,
status: 'done',
userId: 1
},
{
_id: new ObjectId(),
pageNumber: 10,
status: 'done',
userId: 1
}]
然后,我们可以运行以下聚合查询:
> db.logs.aggregate([ {$group: { _id: { "pageNumber" : "$pageNumber", "status" : "$status"}, count : {$sum : 1}}} ]).pretty()
{ "_id" : { "pageNumber" : 8, "status" : "done" }, "count" : 1 }
{ "_id" : { "pageNumber" : 7, "status" : "done" }, "count" : 1 }
{ "_id" : { "pageNumber" : 6, "status" : "done" }, "count" : 1 }
{ "_id" : { "pageNumber" : 4, "status" : "in progress" }, "count" : 1 }
{ "_id" : { "pageNumber" : 9, "status" : "done" }, "count" : 2 }
{ "_id" : { "pageNumber" : 3, "status" : "in progress" }, "count" : 1 }
{ "_id" : { "pageNumber" : 10, "status" : "done" }, "count" : 2 }
{ "_id" : { "pageNumber" : 2, "status" : "in progress" }, "count" : 1 }
{ "_id" : { "pageNumber" : 5, "status" : "in progress" }, "count" : 1 }
{ "_id" : { "pageNumber" : 1, "status" : "in progress" }, "count" : 1 }
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.