如何使用 JPA 避免实体关系中的外键约束冲突

Question

@Entity
@Table(name = "PERSISTENCE_USER")

    public class User implements Serializable {
        // HERE IS A SNIPPET
        @Id
        @GeneratedValue(strategy = GenerationType.AUTO)
    
        private Long id;
        @NotNull
        private String firstName;
        @NotNull
        private String lastName;
        ................
    }
@Entity
@Table(name = "PERSISTENCE_ORDER")
@NamedQueries({
    @NamedQuery(
            name = "findAllorders",
            query = "SELECT o FROM CustomerOrder o"
    ),
    @NamedQuery(
            name = "deleteAll",
            query = "DELETE FROM CustomerOrder"
    )
})

    public class CustomerOrder implements Serializable {
    
        //HERE IS A SNIPPET
        @Id
        @GeneratedValue(strategy = GenerationType.AUTO)
        private Long id;
        @NotNull
        String status;
        @NotNull
        @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
        private List<LineItem> lineItems;
        @NotNull
        @ManyToOne
        private User customer;
        ...........
    }

当我尝试删除与用户实体具有单向@ManyToOne 的 CustomerOrder 实体时，出现以下错误：

Internal Exception: org.apache.derby.shared.common.error.DerbySQLIntegrityConstraintViolationException: DELETE on table 'PERSISTENCE_ORDER' caused a violation of foreign key constraint 'PRSSTNCSRPRSSRDRSD' for key (21).  The statement has been rolled back.
Error Code: 20000
Call: DELETE FROM PERSISTENCE_ORDER
Query: DeleteAllQuery(name="deleteAll" referenceClass=CustomerOrder sql="DELETE FROM PERSISTENCE_ORDER")
    at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:331)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:905)
    at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeNoSelect(DatabaseAccessor.java:967)
        ............................................................................
        ............................................................................
Caused by: org.apache.derby.shared.common.error.DerbySQLIntegrityConstraintViolationException: DELETE on table 'PERSISTENCE_ORDER' caused a violation of foreign key constraint 'PRSSTNCSRPRSSRDRSD' for key (21).  The statement has been rolled back.

之后，我尝试先删除 User 实体，然后再删除 CustomerOrder 实体，但这没有任何区别。我应该如何定义实体关系映射以避免此错误？

谢谢

PS：我在 Windows 10 64 位和 Apache Derby DB 上使用带有 EclipseLink 运行的 Glassfish 5.1

Answer 1

发出“DELETE FROM CustomerOrder”批量删除查询时，JPA 不会为您做任何事情 - 它发出 SQL 完全按照此 JPQL 的要求 - 因此由您来维护在删除之前取消或删除对要删除的行的任何引用。

异常本身表明 FK 约束 'PRSSTNCSRPRSSRDRSD' 被违反，可以在数据库中找到它来告诉您究竟是哪个关系导致了问题。查看 CustomerOrder 实体，lineItems 集合的映射方式是将外键放入 LineItems table，这需要在删除成功之前清理这些行。

如何使用 JPA 避免实体关系中的外键约束冲突

How to avoid foreign key constraint violationin in entity relationships using JPA

java

jdbc

eclipselink

jpa-2.1

java-ee-8