mongorepository spring boot custom query

To perform a custom query using MongoRepository in Spring Boot, follow these steps:

1. Define an interface that extends the MongoRepository interface. This interface will provide the basic CRUD operations and query methods for your MongoDB collection.

2. Inside the interface, declare a method with the desired query logic. You can use the method name conventions provided by Spring Data MongoDB to define the query. For example, if you want to find documents by a specific field, you can name the method "findByFieldName". You can also use keywords like "And", "Or", "Between", etc., to combine multiple criteria.

3. Annotate the method with the appropriate query annotation. For example, you can use the @Query annotation to define a custom query using the MongoDB query language. Inside the annotation, you can write the MongoDB query using the JSON-like syntax.

4. If your query requires parameters, you can pass them as method arguments. In the query annotation, you can refer to these parameters using the "?" placeholder. For example, if you have a method parameter named "name", you can refer to it in the query as "?0".

5. Optionally, you can specify additional query options like sorting and pagination. For example, you can add the @Sort annotation to specify the sorting order of the query results.

6. Save the changes and run your Spring Boot application. The custom query will be executed when the corresponding method is invoked.

Remember to replace the placeholders and modify the code according to your specific requirements.