CrudRepository和Hibernate：保存（列表< S>）vs保存（实体）在事务中 [英] CrudRepository and Hibernate: save(List<S>) vs save(Entity) in transaction

问题描述

如果我这样做，会有什么区别：

  @Transactional 
 public void processData（）{
列表< MyEntity>实体= ....; 
 MyEntityRepository.save（entities）; 
} 
  

vs。

  @Transactional 
 public void processData（）{
 List< MyEntity>实体= ....; 
 for（MyEntity entity：entities）{
 MyEntityRepository.save（entity）; 
 
 
 $ / code> $ / pre> 
 
 
底层查询和性能？
解决方案
 来自 SimpleJpaRepository ： 
 
 
  @Transactional 
 public< S extends T>列表与LT; S>更多保存（Iterable< S>实体）{
 
 List< S> result = new ArrayList< S>（）; 
 
 if（entities == null）{
 return result; （S实体：实体）{
 result.add（save（entity））; 
} 
 
 
} 
 
返回结果; 
 
 
 
 
 
 $ b因此，你的第二个商业方法只会影响 save（ Iterable< S>实体） Crud Repository方法，它是迭代列表并以您的名义调用 save（S） p> 
 
 
只要您的 processData 业务方法中的交易被标定，就没有真正的性能差异或执行的查询。 
Would it make any difference if I do:
@Transactional
public void processData() {
    List<MyEntity> entities = ....;
    MyEntityRepository.save(entities);
}
vs.
@Transactional
public void processData() {
    List<MyEntity> entities = ....;
    for (MyEntity entity : entities) {
        MyEntityRepository.save(entity);
    }
}
What is the difference in terms of the underlying queries and performance?
解决方案
From SimpleJpaRepository: 
@Transactional
public <S extends T> List<S> More save(Iterable<S> entities) {

    List<S> result = new ArrayList<S>();

    if (entities == null) {
        return result;
    }

    for (S entity : entities) {
        result.add(save(entity));
    }

    return result;
}
So, your second business method only shadows save(Iterable<S> entities) Crud Repository method, in the sense that it iterates the list and calls save(S) on your behalf.

As long as transaction is demarcated from your processData business method, there is no really a difference in performance or queries executed.

                        
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