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java - JPA 与 Hibernate - 序列不适用于 XML

转载 作者:行者123 更新时间:2023-11-30 04:20:17 25 4
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我第一次将 JPA 与 Hibernate 结合使用,并尝试使用 Oracle 数据库中的现有序列设置自动 ID 生成。

我的实体映射如下所示:

<?xml version="1.0" encoding="UTF-8"?>
<entity-mappings xmlns="http://java.sun.com/xml/ns/persistence/orm"
version="2.0">

<entity class="AmmAdapter.DataAccessLayer.Models.AmmSyncTypePriorities">
<table name="AMM_SYNC_TYPE_PRIORITIES" schema="TESTESTERON" catalog=""/>
<attributes>
<id name="id">
<column name="ID" nullable="false" length="10"/>
<generated-value strategy="SEQUENCE" generator="MODEL_SEQ"/>
<sequence-generator name="MODEL_SEQ" sequence-name="AMM_ED_GROUP_TYPES_SEQ"/>
</id>
<basic name="priority">
<column name="PRIORITY" nullable="false" length="10"/>
</basic>
<one-to-many name="ammSyncMessageTypesesById" mapped-by="ammSyncTypePrioritiesByPriority"
target-entity="AmmAdapter.DataAccessLayer.Models.AmmSyncMessageTypes"/>
</attributes>
</entity>
</entity-mappings>

我的 Java 类如下所示: 包AmmAdapter.DataAccessLayer.Models;

import java.util.Collection;

public class AmmEdGroupTypes
{
private Integer id;

public Integer getId()
{
return id;
}

public void setId(Integer id)
{
this.id = id;
}

private String name;

public String getName()
{
return name;
}

public void setName(String name)
{
this.name = name;
}

@Override
public boolean equals(Object o)
{
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;

AmmEdGroupTypes that = (AmmEdGroupTypes)o;

if (id != null ? !id.equals(that.id) : that.id != null) return false;
if (name != null ? !name.equals(that.name) : that.name != null) return false;

return true;
}

@Override
public int hashCode()
{
int result = id != null ? id.hashCode() : 0;
result = 31 * result + (name != null ? name.hashCode() : 0);
return result;
}

private Collection<AmmEndDeviceGroups> ammEndDeviceGroupsesById;

public Collection<AmmEndDeviceGroups> getAmmEndDeviceGroupsesById()
{
return ammEndDeviceGroupsesById;
}

public void setAmmEndDeviceGroupsesById(Collection<AmmEndDeviceGroups> ammEndDeviceGroupsesById)
{
this.ammEndDeviceGroupsesById = ammEndDeviceGroupsesById;
}
}

我的序列 AMM_ED_GROUP_TYPES_SEQ 有:

最小值:1

最大值:9999999999999999999999999999

增量:1

我使用以下测试代码来确定自动生成是否正常工作: EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("AdapterPersistence");

EntityManager entityManager = entityManagerFactory.createEntityManager();

entityManager.getTransaction().begin();

AmmEdGroupTypes newGroup = new AmmEdGroupTypes();
newGroup.setName("test");

System.out.println(newGroup.getId());

结果我得到一个空 ID。有人知道问题是什么吗?

最佳答案

EntityManager entityManager = entityManagerFactory.createEntityManager();

entityManager.getTransaction().begin();

AmmEdGroupTypes newGroup = new AmmEdGroupTypes();
newGroup.setName("test");
entityManager.persist(newGroup);
entityManager.getTransaction().commit();
System.out.println(newGroup.getId());

关于java - JPA 与 Hibernate - 序列不适用于 XML,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17214586/

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