aggregation-framework

问题 I'm unable to use maxTimeMS parameter with Mongo 2.6 and Pymongo 2.7.1 As per the documentation on this page Official Mongodb Aggregation Page the aggregation method should return a Cursor object. However, when I run the query locally on a mongod instance (2.6+) with pymongo 2.7.1, I get a dict object! In [14]: obj = coll.aggregate({'$group': {'_id': '$l', 'n': {'$sum': 1}}}) In [15]: type(obj) Out[15]: dict Can anyone help me understand what is happening here? 回答1: Yes, you can use maxTimeMS

问题 I'm unable to use maxTimeMS parameter with Mongo 2.6 and Pymongo 2.7.1 As per the documentation on this page Official Mongodb Aggregation Page the aggregation method should return a Cursor object. However, when I run the query locally on a mongod instance (2.6+) with pymongo 2.7.1, I get a dict object! In [14]: obj = coll.aggregate({'$group': {'_id': '$l', 'n': {'$sum': 1}}}) In [15]: type(obj) Out[15]: dict Can anyone help me understand what is happening here? 回答1: Yes, you can use maxTimeMS

问题 I have a collection with documents similar to such: { "_id": ObjectId("xxxxx"), "item": [ { "property": ["attr1", "+1"] }, { "property": ["attr2", "-1"] } ] } { "_id": ObjectId("xxxxy"), "item": [ { "property": ["attr1", "-1"] }, { "property": ["attr2", "0"] } ] } { "_id": ObjectId("xxxxz"), "item": [ { "property": ["attr1", "0"] }, { "property": ["attr2", "+1"] } ] } Preferably using an aggregation pipeline, is there any way to match the document if and only if any one of the properties

问题 I'm simply trying to write a mongo query like in SQL: SELECT LENGTH(binaryBody) AS bodyLength FROM documents; To do so I thought I have to use the projection of the find method. db.documents.find( {<query>}, { bodyLength: {$size: 'body'}} ); But how to do that? Error: error: { "waitedMS" : NumberLong(0), "ok" : 0, "errmsg" : "Unsupported projection option: bodyLength: { $size: \"body\" }", "code" : 2 } 回答1: .find() does not "alter" documents returned in any way. You can only "include" or

问题 I have documents with a schema such as follows: { "user_id": 123, "services":[ {"name": "test", "data": ... }, {"name": "test1", "data": ... }, {"name": "test2", "data": ... } ] } I'm trying to get a service by name for a specific user_id returned as follows: {"name": "test2", "data": ... } I'm having difficulty wrapping my head around how to do this and seems an aggregation shouldn't be needed for something as simple as this but maybe I'm wrong. I'm sure a projection would work in a find_one

问题 I am doing mongo db aggregation like $cursor = $this->collection->aggregate( array( array( '$project' => array( 'FullName' => array('$concat' => array('$first_name', ' ', '$middle_name', ' ', '$last_name')), 'FirstMiddle' => array('$concat' => array('$first_name', ' ', '$middle_name')), 'FirstLast' => array('$concat' => array('$first_name', ' ', '$last_name')), 'FirstName' => array('$concat' => array('$first_name')), 'MiddleName' => array('$concat' => array('$middle_name')), 'LastName' =>

问题 How can i set " allowDiskUse " option in aggregation method in spring data-mongodb framework ? 回答1: The core aggregation abstraction in Spring Data MongoDB is - as the name suggests - Aggregation . It exposes a fluent API to build up a pipeline using aggregation operations. As of version 1.6.0.M1 the Aggregation class has a ….withOptions(…) method to be used like this: Aggregation aggregation = newAggregation(…) // build up pipeline in here .withOptions(newAggregationOptions().allowDiskUse

问题 In an aggregation process I've got this data: { "_id" : "billing/DefaultController/actionIndex", "min_time" : 0.033, "max_time" : 5.25, "exec_time" : 555.490999999997, "qt" : 9059, "count" : 2, "date" : [ ISODate("2014-02-10T00:00:00.000Z"), ISODate("2014-02-11T00:00:00.000Z") ] }, How to change my query: db.page_speed_reduced.aggregate([ {$group: { _id: "$value.route", min_time: {$min: "$value.min_time"}, max_time: {$max: "$value.max_time"}, exec_time: {$sum: "$value.exec_time"}, qt: {$sum:

问题 I have a data as follows: > db.PQRCorp.find().pretty() { "_id" : 0, "name" : "Ancy", "results" : [ { "evaluation" : "term1", "score" : 1.463179736705023 }, { "evaluation" : "term2", "score" : 11.78273309957772 }, { "evaluation" : "term3", "score" : 6.676176060654615 } ] } { "_id" : 1, "name" : "Mark", "results" : [ { "evaluation" : "term1", "score" : 5.89772766299929 }, { "evaluation" : "term2", "score" : 12.7726680028769 }, { "evaluation" : "term3", "score" : 2.78092882672992 } ] } { "_id" :

问题 I have a Mongo collection that looks as follows: [{ id: 1, timestamp: 1534488870841, type: 'deposit' }, { id: 1, timestamp: 1534488915119, type: 'deposit' }] How can I make a query to list all deposit transactions, grouped by the month. The month must be calculated using the timestamp attribute (UNIX millisecond). I can get the deposit's as follows but I am unsure on how to group: db.getCollection('transactions').find( {"type":"deposit"}); Edit : Mongo version 3.4 回答1: You can try below