mongodb-query

This question already has answers here : Check that Field Exists with MongoDB (4 answers) Closed 8 months ago . I am trying to figure out how to match a key and return all the values for that key. Is it possible to give the value as a wildcard? I want to return everything for that specific key using wildcard on the value. db.collection.find({"key" :"*"}) Also I was hoping this would return the entire collection as well that had the key with the wildcard value match as well. You may be looking for something like this: db.collection.find({"key": {$exists: true}}) This will return all documents

This is my collection: { "_id" : 10926400, "votes": 131, "author": "Jesse", "comments" : [ { "id" : 1, "votes": 31, "author": "Mirek" }, { "id": 2, "votes": 13, "author": "Leszke" } ] }, { "_id" : 10926401, "votes": 75, "author": "Mirek", "comments" : [ { "id" : 1, "votes": 17, "author": "Jesse" }, { "id": 2, "votes": 29, "author": "Mirek" } ] } And I want $sum values of votes and comments.votes of each author expected output( sort $votes: -1 ): "Mirek" total votes: 31 + 75 + 29 = 135 "Jesse" total votes: 131 + 17 = 148 "Leszke total votes: 13 Not immediately visible but possible. What you

I have an object with the following form : { "_id": ObjectId("4fa43f4d1cf26a6a8952adf1"), "userId": "1", "facebookId": "1234", "groups": [{ "groupName": "testGroup", "members": [{ "memberFirstName": "userFirstName", "memberLastName": "userLastName", "memberDetails": { "userId": "1", "faceBookId": "1234" } }] }] } It's a collection that holds for each user - its groups, with each group containing the group members... So the "groups" key is an array (or list), and so is the "members" key. (each user could have multiple groups, each group has multiple group members). I'm having a hard time

I have a collection faults in my MongoDB database which every document has these fields: rack_name , timestamp Just for sake of testing and comparing performances, I have created these two indexes: rack -> {'rack_name': 1} and time -> {'timestamp': 1} Now I executed the following query with explain(): db.faults.find({ 'rack_name': { $in: [ 'providence1', 'helena2' ] }, 'timestamp': { $gt: 1501548359000 } }) .explain('allPlansExecution') and here is the result: { "queryPlanner" : { "plannerVersion" : 1, "namespace" : "quicktester_clone.faults", "indexFilterSet" : false, "parsedQuery" : { "$and"

I have 2 collections (with example documents): reports { id: "R1", type: "xyz", } reportfiles { id: "F1", reportid: "R1", time: ISODate("2016-06-13T14:20:25.812Z") }, { id: "F14", reportid: "R1", time: ISODate("2016-06-15T09:20:29.809Z") } As you can see one report may have multiple reportfiles . I'd like to perform a query, matching a report id , returning the report document as is, plus an additional key storing as subdocument the reportfile with the most recent time (even better without reportid , as it would be redundant), e.g. { id: "R1", type: "xyz", reportfile: { id: "F14", reportid:

I have a match expression in a mongodb aggregation. There are 3 fields that are included in the match but they don't all always contain data. I only want to include the fields in the match if the field isn't empty. This is what the match looks like if all fields have data but for example, if the array used for studentGradeLevels is empty, then I don't want to include it or I want the query to still return data ignoring the empty parameter. $match: { "school._id": "7011", "studentGradeLevels": { $in: ["09", "10", "11", "12"] }, "contentArea": { $in: [ "English 1" ] } } Is there a way to either

With a collection of documents with fields field1 , field2 , field3 and so on, I need to find distinct values for field3 for each distinct value of field3 , need to get the first document with each distinct value in field3 For # 1, I could do db.myCollection.distinct("field3") How do I go about #2 ? Sample Collection: [ { "field1": 11, "field2": "toyota", "field3": "camry" }, { "field1": 22, "field2": "toyota", "field3": "corolla" }, { "field1": 33, "field2": "toyota", "field3": "camry" }, { "field1": 44, "field2": "honda", "field3": "accord" }, { "field1": 55, "field2": "honda", "field3":

I have collection in my mongoDB which stores service given to customer along with their email address something like below { "_id" : ObjectId("56a84627f8fd4a136c0e944a"), "Vehicle" : "Honda", "ServiceSelected" : "FULL SERVICE", "FullName" : "xyz", "Email" : "xyz@xyz.com", "BookingTime" : ISODate("2015-12-27T06:00:00.000Z") }, { "_id" : ObjectId("56a84627f8fd4a136c0e944b"), "Vehicle" : "AUDI", "ServiceSelected" : "FLAT TYRE", "FullName" : "abc", "Email" : "abc@abc.com", "BookingTime" : ISODate("2015-12-26T06:00:00.000Z") }, { "_id" : ObjectId("56a84627f8fd4a136c0e944c"), "Vehicle" : "BMW",