If you are on MongoDB 3.0 or newer, you need to use the .findOneAndUpdate() and use projection option to specify the subset of fields to return. You also need to set returnNewDocument to true. Of course you need to use the $elemMatch projection operator here because you cannot use a positional projection and return the … Read more
You need to use insert_many method and set the ordered option to False. db_stock.insert_many(<list of documents>) As mentioned in the ordered option documentation: ordered (optional): If True (the default) documents will be inserted on the server serially, in the order provided. If an error occurs all remaining inserts are aborted. If False, documents will be … Read more
You can only use the $ positional operator for single-level arrays. In your case, you have a nested array (heros is an array, and within that each hero has a spells array). If you know the indexes of the arrays, you can use explicit indexes when doing an update, like: > db.test.update({“heros.nickname”:”test”, “heros.spells.spell_id”:1}, {$set:{“heros.0.spells.1.level”:3}});
Unfortunately the mgo.v2 driver does not provide API calls to specify cursor.min(). But there is a solution. The mgo.Database type provides a Database.Run() method to run any MongoDB commands. The available commands and their documentation can be found here: Database commands Starting with MongoDB 3.2, a new find command is available which can be used … Read more
Querying this structure for the results you want is not possible without knowing all of the possible forms names beforehand, and using them in the query. It would be very messy at any rate. That said, read on as I explain how it can be done. There is a problem with the structure of these … Read more
Right now, I don’t think it’s possible to do this with one operation. The bitwise operators (http://www.mongodb.org/display/DOCS/Updating#Updating-%24bit) don’t have a ‘$xor’ yet although I’ve a patch for it. Right now the workaround I think think of is by always using ‘$inc’: cl.update( { “_id”: …}, { ‘$inc’ : { ‘field’ : 1 } } ); … Read more
You can specify multiple fields to the $push operator db.collection.update( { _id :1 }, { $push : { array1 : “1”, array2 : “5” }} )
It’s called natural order: natural order The order in which the database refers to documents on disk. This is the default sort order. See $natural and Return in Natural Order. This confirms that in general you get them in the same order you inserted, but that’s not guaranteed–as you noticed. Return in Natural Order The … Read more
Suppose the bottom left coordinates and the upper right coordinates are respectively [0, 0] and [100, 100]. From MongoDB 3.2 you can use the $slice operator to return a subset of an array which is what you want. db.collection.aggregate([ { “$match”: { “loc”: { “$geoWithin”: { “$box”: [ [0, 0], [100, 100] ] } }} … Read more
So basically using .aggregate() instead of .find(): db.tweets.aggregate([ { “$project”: { “_id”: 0, “coords”: “$level1.level2.coordinates” }} ]) And that gives you the result that you want. MongoDB 2.6 and above versions return a “cursor” just like find does. See $project and other aggregation framework operators for more details. For most cases you should simply rename … Read more