Mongodb query show only one field
Web1 mrt. 2024 · here, "abc123" is unique to that collection and assigned by mongo, and "12345" is the _id of some record in Meteor.users. so you can find it like this (this would be on the client, and you would have already subscribed to DBInfos collection): let userId = Meteor.userId (); let matchingInfos = DBInfos.find ( {userId: userId}); the first userId ... Web24 apr. 2014 · 2. db.collection_name.distinct ("key/field_name") - This will return a list of distinct values in the key name from the entire dictionary. Just make sure you don't use the curly brackets after round brackets. Share.
Mongodb query show only one field
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Web13 dec. 2024 · But i only want to get the specific element from that array. I cant find it in the document. ... This can choose which field you want ( or just remove which field you don't want) and rename a field to what you want. ... How to filter and map array of documents in MongoDB query? Related. 41. Web20 mrt. 2016 · In order to optimize query performance, I want to specify fields I really need and fetch only them. I found couple of examples, such as: BasicDBObject query = new …
WebMongoDB provides various query operators to specify the criteria. The following operation uses the $in operator to return documents in the bios collection where _id equals either … WebIf you specify a projection parameter, findOne () returns a document that only contains the projection fields. The _id field is always included unless you explicitly exclude it. Although similar to the find () method, the findOne () method returns a document rather than a cursor.
WebMongoDB aggregation with $lookup only include (or project) some fields to return from query. In mongo, after doing an aggregation with $lookup, I would like the request to … Web5 jan. 2024 · This is simple SQL query. select groupId from retryBatches where campaignId = campaignId and groupId is not null; How to Write the above in spring data mongodb ? I have done this, but how to fetch only groupId. Query query = new Query(where("campaignId").is(campaignId).and("groupId").ne(null)); Thanks
Web13 dec. 2024 · {'items': [{'item_id': 1}, {'item_id': 2}]} after $unwind {'items': {'item_id': 1}} {'items': {'item_id': 2}} $project. This can choose which field you want ( or just remove …
WebSelect All Documents in a Collection. To select all documents in the collection, pass an empty document as the query filter parameter to the find method. The query filter parameter determines the select criteria: db. inventory. find ( { } ) MongoDB Shell. This operation uses a filter predicate of {}, which corresponds to the following SQL ... gutshof stangl neufarnWeb30 jul. 2024 · MongoDB query select and display only a specific field from the document - Let us first create a collection with documents −> … box type plantsWeb4 nov. 2016 · The first thing you are doing wrong here is not understanding how $project is intended to work. Pipeline stages such as $project and $group will only output the fields … gutshof thomashütte eppertshausenWeb21 aug. 2024 · 4. you can use anonymous class. public class User { public int age; public string a; public string b; } var collection = db.GetCollection ("Users"); var results = … gutshof thansenWeb8 mei 2024 · Everybody. In mongo group query, the result shows only the key(s) in arguments. How to keep the first document in each group like mysql query group. for example: -----... gutshof teichaWeb23 feb. 2015 · To query and return only specific fields, this is the correct request : Data.find({}, { _id : 1, serialno : 1 }, function (err, data) { if(err) { return handleError(res, … gutshof triangelWeb29 jan. 2024 · Your Casts collection shows only 1 document. Your Contents collection, likewise, shows only 1 document. This is 1 to 1 - not 1 to 2. Aggregate is working as … box type relay