java - "org.hibernate.DuplicateMappingException"错误是什么意思？

Question

我试图强制 JPA/Hibernate 只生成和使用小写的表名。我已经实现了这样的 NamingStrategy:

public class MyNamingStrategy extends DefaultNamingStrategy {

  @Override
  public String classToTableName(String className) {
    return super.classToTableName(className).toLowerCase();
  }
}

我通过在 persistence.xml 中设置这个属性来应用它:

<property name="hibernate.ejb.naming_strategy" value="entities.strategy.MyNamingStrategy"/>

当我这样做时，我得到了这个堆栈跟踪:

SEVERE: Exception while invoking class org.glassfish.persistence.jpa.JPADeployer prepare method
org.hibernate.DuplicateMappingException: Same physical table name [planning] references several logical table names: [Planning], [OrderProductMan_Planning]
        at org.hibernate.cfg.Configuration$MappingsImpl.addTableBinding(Configuration.java:2629)
        at org.hibernate.cfg.annotations.TableBinder.buildAndFillTable(TableBinder.java:254)
        at org.hibernate.cfg.annotations.TableBinder.bind(TableBinder.java:177)

什么是

Same physical table name [planning] references several logical table names: [Planning], [OrderProductMan_Planning]

是什么意思？

错误中的实体，已尽可能简化。如果您需要休息，请告诉我。

@Entity
public class Planning implements Serializable {

  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  private Integer id;

  private Integer qty;

  @ManyToOne
  private OrderProductMan orderProduct;

  ....
}


@Entity
@Table
public class OrderProductMan implements Serializable {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  @Basic(optional = false)
  private Integer opId;

  @Basic(optional = false)
  private int qty;

  @ManyToOne(optional = false)
  private ProductMan produse;

  @ManyToOne(optional = false)
  private OrderMan orders;

  @Transient
  private int totalScheduled;

  @Transient
  private int totalProduced;
   // ...
 }

Answer 1

Bogdan，感谢您发帖。对于在 Linux 上使用 Hibernate/JPA/MySQL 的 Unix/Windows 可移植性，我遇到了区分大小写的表名的类似问题。

像你一样，我开始通过在我的 META-INF/persistence.xml 文件中配置自定义 NamingStrategy 来将我的表名绑定(bind)为所有小写:

<property name="hibernate.ejb.naming_strategy" value="my.package.LowerCaseNamingStrategy" />

我遇到了相同的异常:org.hibernate.DuplicateMappingException:相同的物理表名称...通过使用调试器，我顿悟了，也许 我一开始并没有使用 DefaultNamingStrategy!所以我将基类更改为 org.hibernate.cfg.EJB3NamingStrategy。我相信，这在使用 JPA 注释时更合适!这是我最终的 NamingStrategy:

package my.package;

import org.apache.commons.lang.StringUtils;
import org.hibernate.cfg.EJB3NamingStrategy;

public class LowerCaseNamingStrategy extends EJB3NamingStrategy {
    @Override
    public String classToTableName(String className) {
        return StringUtils.lowerCase(super.classToTableName(className));
    }

    @Override
    public String collectionTableName(String ownerEntity, String ownerEntityTable, String associatedEntity,
            String associatedEntityTable, String propertyName) {
        return StringUtils.lowerCase(super.collectionTableName(ownerEntity, ownerEntityTable, associatedEntity, associatedEntityTable, propertyName));
    }

    @Override
    public String logicalCollectionTableName(String tableName, String ownerEntityTable, String associatedEntityTable,
            String propertyName) {
        return StringUtils.lowerCase(super.logicalCollectionTableName(tableName, ownerEntityTable, associatedEntityTable, propertyName));
    }

    @Override
    public String tableName(String tableName) {
        return StringUtils.lowerCase(super.tableName(tableName));
    }
}

PS dursun 之前的解决方案对我不起作用。