Data modeling

In this section, we will discuss the different types of data MongoDB uses, how they map to the data types that programming languages use, and how we can model data relationships in MongoDB using Ruby, Python, and PHP.

Data types

MongoDB uses BSON, a binary-encoded serialization for JSON documents. BSON extends the JSON data types, offering, for example, native data and binary data types.

BSON, compared to protocol buffers, allows for more flexible schemas, which comes at the cost of space efficiency. In general, BSON is space-efficient, easy to traverse, and time-efficient in encoding/decoding operations, as can be seen in the following table (see the MongoDB documentation at https://docs.mongodb.com/manual/reference/bson-types/):

Table 2.1 – MongoDB data types

In MongoDB, we can have documents with different value types for a given field and we can distinguish between them when querying using the $type operator.

For example...