JPA合併拋出異常在刷新期間重複鍵'PRIMARY'的條目

Question

我有一個使用hibernate 5.2和JPA來處理數據庫的spring服務器。

我們有一個過程，收集大量數據並保存基於該數據的事件。它每天都在運行，這些事件可能會改變價值。有時，當我嘗試保存這些內容時，出現以下情況：

15:28:32.819 [pool-6-thread-3] ERROR org.hibernate.engine.jdbc.spi.SqlExceptionHelper - Duplicate entry 'VAL-below_avg-2017-04-07' for key 'PRIMARY' 
Query is: insert into event_date (description, period, time, date, symbol, type) values (?, ?, ?, ?, ?, ?, ?) 
Query is: 
insert into event_date (description, period, time, date, symbol, type) values (?, ?, ?, ?, ?, ?, ?) 
[org.hibernate.exception.ConstraintViolationException: could not execute statement] 
15:28:32.822 [pool-6-thread-3] ERROR org.hibernate.internal.ExceptionMapperStandardImpl - HHH000346: Error during managed flush [org.hibernate.exception.ConstraintViolationException: could not execute statement] 
org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint [PRIMARY]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement 
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:278) 
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:244) 
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:521) 
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:761) 
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:730) 
    at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:504) 

我們在這裏沒有做任何事情。我們處理數據。我們創建新的對象。我們將它們傳遞到下面的方法在我們的DAO：

public void saveOrUpdate(List<EventDate> events) { 
    for (EventDate e : events) { 
     try{ 
      entityManager.merge(e); 
     }catch(Exception e1){ 
      logger.error("Something broke!"); 
     } 
    } 
} 

我已經通過大約十幾個類似的問題了，但在所有這些，這個問題似乎被某種與另一對象定向關係引起的。就我而言，沒有這樣的事情。我也看到一些人認爲這是一個沒有hashcode和equals的問題，所以我實現了這些無濟於事。

我的實體類如下所示（有繼承EVENTDATE許多實體，但他們大多隻是在這裏添加一些元屬性和在那裏，我不認爲問題在於他們：

@Entity 
@Table(name = "event_date") 
@Inheritance(strategy=InheritanceType.SINGLE_TABLE) 
@DiscriminatorColumn(name="type", discriminatorType=DiscriminatorType.STRING, length=255) 
@DiscriminatorOptions(insert=false) 
@JsonIgnoreProperties(ignoreUnknown=true) 
public abstract class EventDate implements Serializable { 
    private static final long serialVersionUID = 1L; 

    @EmbeddedId 
    private SymDateTypeId id; 

    @Column(columnDefinition=COLUMN_DATETIME) 
    private String time = "UNKNOWN"; 

    @Column(columnDefinition=COLUMN_TEXT) 
    private String description; 

    @Column(columnDefinition=COLUMN_VARCHAR20) 
    private String period; 

    //Getters/Setters/Hashcode/Equals omitted... 
} 

@Embeddable 
public class SymDateTypeId implements Serializable{ 
    private static final long serialVersionUID = 1L; 

    @Column(nullable=false) 
    private String symbol = "UNKNOWN"; 
    @Column(nullable=false) 
    private String date = "UNKNOWN"; 
    @Column(nullable=false) 
    private String type; 

    //Getters and setters omitted... 

    @Override 
    public int hashCode() { 
     final int prime = 31; 
     int result = 1; 
     result = prime * result + ((date == null) ? 0 : date.hashCode()); 
     result = prime * result + ((symbol == null) ? 0 : symbol.hashCode()); 
     result = prime * result + ((type == null) ? 0 : type.hashCode()); 
     return result; 
    } 
    @Override 
    public boolean equals(Object obj) { 
     if (this == obj) 
      return true; 
     if (obj == null) 
      return false; 
     if (getClass() != obj.getClass()) 
      return false; 
     SymDateTypeId other = (SymDateTypeId) obj; 
     if (date == null) { 
      if (other.date != null) 
       return false; 
     } else if (!date.equals(other.date)) 
      return false; 
     if (symbol == null) { 
      if (other.symbol != null) 
       return false; 
     } else if (!symbol.equals(other.symbol)) 
      return false; 
     if (type == null) { 
      if (other.type != null) 
       return false; 
     } else if (!type.equals(other.type)) 
      return false; 
     return true; 
    } 
} 

Answer 1

Duplicate entry 'VAL-below_avg-2017-04-07' for key 'PRIMARY' 

明確表明您已經有了相關的行中，你的數據庫，嘗試找出爲什麼你保存的事件兩次，一切都很好。你可能會增加也日誌條目源。