Offset Pagination - Trigger SELECT COUNT Subquery And Return Page<projection> That Maps Entities And The Total Number Of Records Via Projection

Description: This application fetches data as Page<projection> via Spring Boot offset pagination. The projection maps the entity and the total number of records. This information is fetched in a single database rountrip because the SELECT COUNT triggered for counting the total number of records is a subquery of the main SELECT.

Key points:

• define a Spring projection that maps the entity and the total number of records
• write a repository that extends PagingAndSortingRepository
• fetch data via a JPQL query into a List<projection>
• use the fetched List<projection> and Pageable to create a Page<projection>

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