Examples of Spring Data JDBC integration

spring_data_jdbc_integration_example.java

@Repository
public interface NorthAccountRepository
    extends PagingAndSortingRepository<NorthAccount, Integer>,
        ScalarDbHelperRepository<NorthAccount> {

  @Transactional
  default void transferToSouthAccount(
      @Nonnull SouthAccountRepository southAccountRepository,
      int fromId, int toId, int value) {

    NorthAccount fromEntity =
        findById(fromId).orElseThrow(() -> new AssertionError("Not found: " + fromId));
    SouthAccount toEntity =
        southAccountRepository
            .findById(toId)
            .orElseThrow(() -> new AssertionError("Not found: " + toId));
    update(new NorthAccount(fromEntity.id, fromEntity.balance - value));
    southAccountRepository.update(new SouthAccount(toEntity.id, toEntity.balance + value));
  }

  @Transactional
  default void deleteAfterSelect(int id) {
    findById(id).ifPresent(this::delete);
  }
}