Starting with the 3.2 release, you can use the new $filter aggregation operator to filter an array during projection, which has the benefit of including all matches, instead of just the first one. When you query a collection using the db.collection.find() method, you can append limit() to specify the limit. That thought alone and the fact that a unique ID through out all databases for each price would be a nice to have, made me decide for a GUID instead of. The value you see is actually a base64 encoded string of the GUID value. Far from the previous useless sentence though, mind the blue square because this is how MongoDB stores a GUID. You should first convert your UUID in base64, to do so I used 2 online converters, the first one gave me the 12 first base64 caracters, the second one the 12 last (yes, this is strange). In projections that explicitly excludes fields, the id field is the only field that you can explicitly include however, the id field is included by default. MongoDB 2.2's new $elemMatch projection operator provides another way to alter the returned document to contain only the first matched shapes element: db.test.find( MongoDB Compass GUID The capture above is showing a part of MongoDB compass connected to a beta database with partially real but old data, located locally.
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