[英]get all data in a mongo collection into a text file using javascript
[英]Querying data from Mongo collection using javascript
這是我第一次將mongo用於流星項目,這是為了幫助一群用戶協作閱讀聖經。 集合的數據結構如下:
//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.
]
我正在嘗試找出以下幾點:
現在由於我對mongo的了解有限,所以我被困在這一點上。 我一直在研究各種解決方案,但不確定哪一種是合適的:
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
}
]
如果有人可以對此做一些更深入的了解,我將不勝感激。 這可能很明顯,但是我發現它有點困難。 謝謝。
我會嘗試根據您要實現的用途對文檔進行建模,如果將日志分成僅讀取的頁面,則可以進行簡單的分組依據。
假設我們將您的模型更改為以下內容:
[{
_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,我們可以運行以下聚合查詢:
> 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 }
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