The feature is not well (read: at all) documented, but after reading through the source code, I came up with the following solution. Create your collection schema. var Counters = new Schema({ _id: String, next: Number }); Create a static method on the schema which will expose the findAndModify method of the model’s collection. Counters.statics.findAndModify … Read more
I fixed the problem cleaning the old volumes with the next command: $ docker volume rm $(docker volume ls -qf dangling=true) Reference: docker-cleanup-volumes Update: 07/13/2018 Docker now has a built in command for removing dangling volumes: docker volume prune.
I solved this problem by declining to install Compass together with Mongo in the installer wizard.
This is an old question but stumbling across it, I don’t think the accepted answer answers the question. The question wasn’t “What is MongoEngine?” – it was “Why should I use MongoEngine?” And the advantages of such an approach. This goes beyond Django to Python/Mongo in general. My two cents: While both PyMongo and MongoEngine … Read more
Man, I had a similar issue creating an Schema like this: QuestionnaireSchema = mongoose.Schema({ formId: Number, name: String, questions: [ { type: String, title: String, alternatives:[{ label: String, value: “Mixed” }] } ] }); My mistake was that I am using “type” as a field name and this is reserved word in mongoose. I just … Read more
Or if you are using a Criteria API Criteria criteria = new Criteria(); criteria.orOperator(Criteria.where(“A”).is(10),Criteria.where(“B”).is(20)); Query query = new Query(criteria); mongoOps.find(query, <Yourclass>.class, “collectionName”);
If you are looking for a way to create a data model to communicate your design, there are no tools out there specifically created to model json-structured data. However, you could use UML tools or XML design tools to create your models. I’ve been less than satisfied with both methods, but it’s all I have … Read more
To expand on Blakes Seven’s answer, all the updateOne method does is simply set the multi option to false as seen here (github). And in turn all the updateMany method does is set the multi opion to true as seen here (github). So there is no “better” method to call, just pick whichever you feel … Read more
Note: This was written back in 2013 when MongoDB was still quite young, it didn’t have the features it does today, while this answer still holds true for mmap, it does not for the other storage technologies MongoDB now implements, such as WiredTiger, or Percona. A good place to start to understand exactly what is … Read more
The MongoDB query optimizer works by trying different plans to determine which approach works best for a given query. The winning plan for that query pattern is then cached for the next ~1,000 queries or until you do an explain(). To understand which query plans were considered, you should use explain(1), eg: db.col.find({category:’A’}).sort({updated: -1}).explain(1) The … Read more