properties 파일

spring.application.name=payday

spring.datasource.driver-class-name =com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/PayDayDB?createDatabaseIfNotExist=true
spring.datasource.username=${DB_USERNAME:Mysql DB이름}
spring.datasource.password=${DB_PASSWORD:비밀번호}
spring.jpa.hibernate.ddl-auto=update

JPA persistance (caching) 적용된 object를 사용하여 2차 변경 사항을 적용하는 코드

    @Transactional
    @Override
    public Receipt updateReceiptContentsById(Long receiptId, Receipt receipt) {
        Optional<Receipt> qs = receiptRepository.findById(receiptId);
        if (qs.isPresent()) {
            Receipt p = qs.get();

            //List Clear
            p.getReceiptContents().clear();
            //orphan DropTable : receiptContent
            Receipt flushed = receiptRepository.save(p);


            List<ReceiptContent> data = receipt.getReceiptContents();

            for (ReceiptContent res : data) {
                flushed.getReceiptContents().add(res);
                res.setReceipt(flushed);
            }
            return receiptRepository.save(flushed);


        } else {
            throw new RuntimeException("none");
        }

    }

}

json reference를 적절히 조절하여, 3중 연관구조에서 데이터를 원하는 레이어만큼 꺼내옴

이번엔 entity graph와 dto 안쓰고 해봄.