Document Data Structure in MongoDB Express
MongoDB lets you easily store structured and unstructured data in a flexible and dynamic database schema. It supports CRUD operations on complex data objects using JSON as the main data type.
Its an open source solution so it may not be as robust or well supported as commercial management tools. However it is easy to deploy and works well for most use cases.
The document data structure in mongodb express enables applications to bring together tens or hundreds of disparate sources of information and present them in a single, unified view. The flexibility of the document model allows the embedding of documents to describe nested structures and easily tolerates changes in data across generations of documents. It also efficiently supports specialized data formats such as geospatial.
Each document in a collection has an _id field. It can contain values of any BSON type, except arrays, regular expressions and undefined. Using UUIDs as the _id value can help optimize replication and reduce storage requirements.
Compound queries specify conditions for more than one field in a document. MongoDB reorders fields in the result of a query as needed to achieve efficient execution. For more information, see Query and Projection Operators.
In MongoDB, a Collection is a JSON-like group of documents. It differs from the SQL workflow where a document must be pre-defined with a schema, whereas in MongoDB documents are created on-the-fly inside a collection. This allows for a more flexible and versatile schema and is known as the “schema-less” data management paradigm.
For a quick and efficient collection view, Hevo Express supports Async on-demand loading of large document properties (>100KB by default). It also allows you to have a bird’s eye view of your data as nested & large objects are collapsible.
Document Object Model
The Document Object Model (DOM) is a hierarchical representation of an XML or HTML document. It has a root node that represents the document and a series of child nodes for elements, attributes, and text content.
Each field in a BSON document is represented by a SchemaType. These types are used to define how a field behaves in the database. For example, a field can be required to prevent null values. It can also be defined to use a default value in case the user does not provide one.
MongoDB supports change streams, which allow you to listen to changes made in the database without triggering any middleware. This allows you to perform inserts and updates in bulk. You can also filter on a particular field to get the exact data you want. This can be useful for avoiding duplicates. However, you must be connected to a replica set to use this feature.
A schema defines the rules that govern how documents in a collection are saved. A schema also determines how those documents are retrieved from the database.
For example, if a document contains a number, the schema might require that the number be a positive integer and define an enum validator to prevent the value from being set to something invalid, such as 42.
Similarly, the schema may specify that strings must be in a certain range or have a minimum and maximum length. The schema might also include virtual property setters, which allow a developer to set multiple values for a field in one operation.
Mongoose checks the schema of every write operation against the collection’s schema to ensure that all properties conform to the specified rules. You can configure a collection to only validate new documents against its schema or to check all existing documents and log warnings when the rules are violated. Depending on your application’s data access patterns, you might want to use both validation layers.