Spring Data JPA : 删

参考 Spring Data JPA – Derived Delete Methods

1.通过deletebBy+attribute 来命名删除方法， Derived methods can be defined as VERB + attribute defined in an entity

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.stereotype.Repository;

@Repository
public interface FruitRepository extends JpaRepository<Fruit, String>, JpaSpecificationExecutor<Fruit> {

    Long deleteById(Long id);

    Long deleteByName(String name);

}

调用 需要@Transactional 注解

import javax.transaction.Transactional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class FruitServiceImpl implements FruitService {

    @Autowired
    private FruitRepository fruitRepository;

    @Override
    @Transactional
    public void deleteById(Long id) {

        Long count = fruitRepository.deleteById(id);
    }

    @Override
    @Transactional
    public void deleteByName(String name) {
        Long count = fruitRepository.deleteByName(name);        
    }
    
    
}

 

2.原生sql实现删除

如果字段太多导致 删除方法名太长 或者 比较复杂的业务情况，可以通过写原生sql来实现删除

We may come across a scenario that makes the derived method's name too big or that involves a SQL JOIN between unrelated entities.

 

在Repository层 用@Query注解做查询  @Query 默认是按对象查询，nativeQuery = true：按sql原生语句

增删改操作 需用要@Modifying注解和@Transactional注解，并且返回值只能是int或者Integer。

@Repository
public interface FruitRepository extends JpaRepository<Fruit, Long> {
    @Modifying
    @Query("delete from Fruit f where f.name=:name or f.color=:color")
    List<int> deleteFruits(@Param("name") String name, @Param("color") String color);
}

调用

@Transactional
public void deleteFruits() {
 
     List<int> deletedFruitCount = fruitRepository.deleteFruits("apple"，"green");
}