Working With Documents

Important Concepts in Spring Data MongoDB

Repository: A repository is an interface that provides CRUD (create, read, update, delete) operations for a specific domain object. Spring Data MongoDB provides a number of repository interfaces that you can extend to get started quickly. Document: A document is a MongoDB data object. It is a JSON-like object that can be stored in a MongoDB collection. Query: A query is a way to retrieve documents from a MongoDB collection. Spring Data MongoDB provides a number of query methods that you can use to build queries....

To use Spring Data MongoDB, you need to

Install the Spring Data MongoDB dependency in your project. Create a MongoDB database and collection. Create a Spring Boot application. Configure Spring Data MongoDB in your application. Create a repository interface for your domain object. Use the repository interface to store, retrieve, query, and manage data in MongoDB....

Working With Documents

Define Java classes annotated with @Document to represent documents in MongoDB collections. The class name will be used as the collection name by default. Can specify collection name explicitly using @Document(collection=”collectionName”). Fields in the document are mapped to properties in the Java class. Use annotations like @Id, @Field, etc. to customize mapping. @Id annotation denotes the property that holds the unique identifier value of the document. It can be of any valid type like String, Integer, etc....

Relational Mapping

Repositories provide a more declarative interface for data access compared to imperative MongoTemplate. Define a repository interface extending MongoRepository where EntityType is the document class and IdType is the id property type. This will provide implementations of common CRUD methods like save(), findById(), findAll() etc out of the box without writing any code....

MongoDB Query Language

Query objects are used to build complex MongoDB queries programmatically. Create a Query instance and call methods like where(), regex(), etc. to add criteria. Common criteria methods are: where(criteria) – add a Criteria object regex(field, pattern) – regex match near(point) – geospatial query withinSphere(point, distance) – geospatial query withinPolygon(polygon) – geospatial query...

Example Project

Create a Spring Boot application and Install the Spring Data MongoDB dependency in your project:...