Question

我正在使用Hibernate在MySQL上使用Sakila数据库开发JSF / JPA项目。当我要将客户对象合并到数据库中时，需要20秒。我认为这与我的实体类的映射有关，但是我无法弄清楚自己做错了什么。这是我的客户课程：

@Entity
@Table(name = "customer")
public class Customer implements Serializable, IEntity {

private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "customer_id")
private Short customerId;

@Basic(optional = false)
@Column(name = "first_name")
private String firstName;

@Basic(optional = false)
@Column(name = "last_name")
private String lastName;

@Column(name = "email")
private String email;

@Basic(optional = false)
@Column(name = "active")
private boolean active;

@Basic(optional = false)
@Column(name = "create_date")
@Temporal(TemporalType.TIMESTAMP)
private Date createDate;

@Basic(optional = false)
@Column(name = "last_update")
@Temporal(TemporalType.TIMESTAMP)
private Date lastUpdate;

@LazyCollection(LazyCollectionOption.FALSE)
@OneToMany(cascade = CascadeType.ALL, mappedBy = "customerId")
private List<Rental> rentalList;

@LazyCollection(LazyCollectionOption.FALSE)
@OneToMany(cascade = CascadeType.ALL, mappedBy = "customerId")
private List<Payment> paymentList;

@JoinColumn(name = "address_id", referencedColumnName = "address_id")
@ManyToOne(optional = false)
private Address addressId;

@JoinColumn(name = "store_id", referencedColumnName = "store_id")
@ManyToOne(optional = false)
private Store storeId;

//Constructor 

//getter_setter
}

然后在我的CustomerService ejb中，调用合并功能：

@Named
@Stateless
public class CustomerService {

@PersistenceContext(name = "sakila")
EntityManager em;

public String merge(IEntity entity) {
    try {
        em.merge(entity);
        return "success";
    }catch(Exception e){
        return "failure";
        }
    }
}

在日志中，我可以看到休眠状态就像这样执行了11037个select语句

 select
    paymentlis0_.customer_id as customer5_11_0_,
    paymentlis0_.payment_id as payment_1_11_0_,
    paymentlis0_.payment_id as payment_1_11_1_,
    paymentlis0_.amount as amount2_11_1_,
    paymentlis0_.customer_id as customer5_11_1_,
    paymentlis0_.last_update as last_upd3_11_1_,
    paymentlis0_.payment_date as payment_4_11_1_,
    paymentlis0_.rental_id as rental_i6_11_1_,
    paymentlis0_.staff_id as staff_id7_11_1_,
    rental1_.rental_id as rental_i1_12_2_,
    rental1_.customer_id as customer5_12_2_,
    rental1_.inventory_id as inventor6_12_2_,
    rental1_.last_update as last_upd2_12_2_,
    rental1_.rental_date as rental_d3_12_2_,
    rental1_.return_date as return_d4_12_2_,
    rental1_.staff_id as staff_id7_12_2_,
    customer2_.customer_id as customer1_5_3_,
    customer2_.active as active2_5_3_,
    customer2_.address_id as address_8_5_3_,
    customer2_.create_date as create_d3_5_3_,
    customer2_.email as email4_5_3_,
    customer2_.first_name as first_na5_5_3_,
    customer2_.last_name as last_nam6_5_3_,
    customer2_.last_update as last_upd7_5_3_,
    customer2_.store_id as store_id9_5_3_,
    inventory3_.inventory_id as inventor1_9_4_,
    inventory3_.film_id as film_id3_9_4_,
    inventory3_.last_update as last_upd2_9_4_,
    inventory3_.store_id as store_id4_9_4_,
    staff4_.staff_id as staff_id1_13_5_,
    staff4_.active as active2_13_5_,
    staff4_.address_id as address10_13_5_,
    staff4_.email as email3_13_5_,
    staff4_.first_name as first_na4_13_5_,
    staff4_.last_name as last_nam5_13_5_,
    staff4_.last_update as last_upd6_13_5_,
    staff4_.password as password7_13_5_,
    staff4_.picture as picture8_13_5_,
    staff4_.store_id as store_i11_13_5_,
    staff4_.username as username9_13_5_,
    staff5_.staff_id as staff_id1_13_6_,
    staff5_.active as active2_13_6_,
    staff5_.address_id as address10_13_6_,
    staff5_.email as email3_13_6_,
    staff5_.first_name as first_na4_13_6_,
    staff5_.last_name as last_nam5_13_6_,
    staff5_.last_update as last_upd6_13_6_,
    staff5_.password as password7_13_6_,
    staff5_.picture as picture8_13_6_,
    staff5_.store_id as store_i11_13_6_,
    staff5_.username as username9_13_6_,
    address6_.address_id as address_1_1_7_,
    address6_.address as address2_1_7_,
    address6_.address2 as address3_1_7_,
    address6_.city_id as city_id8_1_7_,
    address6_.district as district4_1_7_,
    address6_.last_update as last_upd5_1_7_,
    address6_.phone as phone6_1_7_,
    address6_.postal_code as postal_c7_1_7_,
    store7_.store_id as store_id1_14_8_,
    store7_.address_id as address_3_14_8_,
    store7_.last_update as last_upd2_14_8_,
    store7_.manager_staff_id as manager_4_14_8_,
    store8_.store_id as store_id1_14_9_,
    store8_.address_id as address_3_14_9_,
    store8_.last_update as last_upd2_14_9_,
    store8_.manager_staff_id as manager_4_14_9_ 
from
    payment paymentlis0_ 
left outer join
    rental rental1_ 
        on paymentlis0_.rental_id=rental1_.rental_id 
left outer join
    customer customer2_ 
        on rental1_.customer_id=customer2_.customer_id 
left outer join
    inventory inventory3_ 
        on rental1_.inventory_id=inventory3_.inventory_id 
left outer join
    staff staff4_ 
        on rental1_.staff_id=staff4_.staff_id 
inner join
    staff staff5_ 
        on paymentlis0_.staff_id=staff5_.staff_id 
inner join
    address address6_ 
        on staff5_.address_id=address6_.address_id 
inner join
    store store7_ 
        on staff5_.store_id=store7_.store_id 
left outer join
    store store8_ 
        on staff5_.staff_id=store8_.manager_staff_id 
where
    paymentlis0_.customer_id=?

Hibernate最终发送更新查询需要20秒钟

Information:   Hibernate: 
update
    customer 
set
    active=?,
    address_id=?,
    create_date=?,
    email=?,
    first_name=?,
    last_name=?,
    last_update=?,
    store_id=? 
where
    customer_id=?

我认为我的映射是错误的，并且将客户配置为延迟加载。有人可以指出我的错误吗？

Answer 1

很显然，为了进行合并，JPA实现（此处为Hibernate）需要知道对分离的实体（或懒惰的，尚未获取的）是否进行了任何更改，因此它正在使用SELECT检查其状态。。由于您是cascadig（使用CascadeType.ALL），因此您将合并到所有相关实体-刷新了整个图。

如果您只需要更新不考虑其子级的父实体，则不要级联合并，或强制合并使用JPQL（或CriteriAPI）更新。

Hibernate合并在更新前执行11000个选择

1 个答案: