无法执行语句;SQL (n / a);约束(null);

Question

我得到这个错误，而从一个特定的模式删除一行:

Hibernate: select journal0_.id as id1_2_0_, journal0_.content as content2_2_0_, journal0_.filename as filename3_2_0_, journal0_.subject as subject4_2_0_, journal0_.tags as tags5_2_0_, journal0_.user_id as user_id6_2_0_, journal0_.version as version7_2_0_ from journal journal0_ where journal0_.id=?
Hibernate: select nextval ('hibernate_sequence')
Hibernate: insert into subscription (journal_id, user_id, version, id) values (?, ?, ?, ?)
2016-09-03 01:08:01.581  WARN 13462 --- [nio-8080-exec-9] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 23505, SQLState: 23505
2016-09-03 01:08:01.581 ERROR 13462 --- [nio-8080-exec-9] o.h.engine.jdbc.spi.SqlExceptionHelper   : Unique index or primary key violation: "UK_9XFQUT5UKXNSBX8NL2LR23TC5_INDEX_9 ON PUBLIC.SUBSCRIPTION(USER_ID, JOURNAL_ID) VALUES (9, 2, 10)"; SQL statement:
insert into subscription (journal_id, user_id, version, id) values (?, ?, ?, ?) [23505-191]
2016-09-03 01:08:01.598  INFO 13462 --- [nio-8080-exec-9] o.h.e.j.b.internal.AbstractBatchImpl     : HHH000010: On release of batch it still contained JDBC statements
2016-09-03 01:08:01.632 ERROR 13462 --- [nio-8080-exec-9] c.j.exceptions.ErrorController           : Exception during execution of SpringSecurity application
org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement

即使调用了带有正确参数的delete方法，它仍然在运行插入查询，这会导致数据冲突问题。

模型如下:

@Entity
@Table(uniqueConstraints={@UniqueConstraint(columnNames={"userId", "journalId"})})
public class Subscription {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
    @Version
    private Integer version;
    private Integer userId;
    private Integer journalId;
    public void setId(Integer id) {
        this.id = id;
    }
    public Integer getId() {
        return this.id;
    }
    public void setVersion(Integer version) {
        this.version = version;
    }
    public Integer getVersion() {
        return this.version;
    }
    public void setUserId(Integer userId) {
        this.userId = userId;
    }
    public Integer getUserId() {
        return this.userId;
    }
    public void setJournalId(Integer journalId) {
        this.journalId = journalId;
    }
    public Integer getJournalId() {
        return this.journalId;
    }
}

这是delete方法被调用的地方:

@Override
public void unsubscribeJournalForSubscriber(Journal journal, Account subscriber) {
    Subscription subscription = new Subscription();
    subscription.setJournalId(journal.getId());
    subscription.setUserId(subscriber.getId());

    this.subscriptionRepository.delete(subscription);
}

Answer 1

如果你想删除记录而不使用主键，那么创建一个查询。在"SubscriptionRepository"中创建一个名为

的方法

@Modifying @Query("delete from Subscription s where s.role. userId = ?1 and s. journalId = ?2") deleteByUserIdJournalId(Integer userId,Integer journalId)然后使用该方法删除您的记录。按照这个https://docs.spring.io/spring-data/jpa/docs/current/reference/html/

Answer 2

删除订阅实体时，只需要设置该实体的"主键"，即订阅实体的id字段。但是，您正在设置journalId和userId字段并试图删除。您应该只设置订阅实体的id字段，它将被删除。

更新:

您的存储库代码应该是

public interface SubscriptionRepository extends CrudRepository<Subscription, Integer> {
    /**
     * Returns array of Subscribed journals by specific user's id
     * 
     * @param userId
     * @return
     */
    ArrayList<Subscription> findByUserId(Integer userId);
    List<Subscription> findByUserIdAndJournalId(Integer userId, Integer journalId);
}

现在您的业务登录代码将是:

@Override
public void unsubscribeJournalForSubscriber(Journal journal, Account subscriber) {
    List<Subscription> list = subscriptionRepository.findByUserIdAndJournalId(subscriber.getId(), journal.getId());
    for(Subscription subscription : list){
        subscriptionRepository.delete(subscription);
    }
}