Java hibernate注释-Inheritation with@MappedSuperclass-未将值设置为基类字段-奇怪的错误
我正在跟踪并将ID、lastModifiedDate等公共列放在基表中 我的注释映射如下所示: 基本表:Java hibernate注释-Inheritation with@MappedSuperclass-未将值设置为基类字段-奇怪的错误,java,hibernate,inheritance,jpa,annotations,Java,Hibernate,Inheritance,Jpa,Annotations,我正在跟踪并将ID、lastModifiedDate等公共列放在基表中 我的注释映射如下所示: 基本表: @MappedSuperclass public abstract class BaseTable { @Id @GeneratedValue @Column(name = "id") private int id; @Column(name = "lastmodifieddate") private Date lastModifiedDat
@MappedSuperclass
public abstract class BaseTable {
@Id
@GeneratedValue
@Column(name = "id")
private int id;
@Column(name = "lastmodifieddate")
private Date lastModifiedDate;
...
create table Person (id integer not null auto_increment, lastmodifieddate datetime, name varchar(255), primary key (id)) ;
insert into Person (lastmodifieddate, name) values (?, ?)
binding parameter [1] as [TIMESTAMP] - <null>
binding parameter [2] as [VARCHAR] - Test
Query query = getSession().createQuery("from " + Person.class.getName());
List<Person> allPersons=query.list();
人员表-
@Entity
@Table(name = "Person ")
public class Person extends BaseTable implements Serializable{
@Column(name = "name")
private String name;
...
生成的Create语句:
@MappedSuperclass
public abstract class BaseTable {
@Id
@GeneratedValue
@Column(name = "id")
private int id;
@Column(name = "lastmodifieddate")
private Date lastModifiedDate;
...
create table Person (id integer not null auto_increment, lastmodifieddate datetime, name varchar(255), primary key (id)) ;
insert into Person (lastmodifieddate, name) values (?, ?)
binding parameter [1] as [TIMESTAMP] - <null>
binding parameter [2] as [VARCHAR] - Test
Query query = getSession().createQuery("from " + Person.class.getName());
List<Person> allPersons=query.list();
将Person对象保存到db后
Person p = new Person();
p.setName("Test");
p.setLastModifiedDate(new Date());
..
getSession().save(p);
我正在设置日期字段,但它正在使用生成的ID和LastModifiedDate=null以及Name=“Test”保存记录
插入语句:
@MappedSuperclass
public abstract class BaseTable {
@Id
@GeneratedValue
@Column(name = "id")
private int id;
@Column(name = "lastmodifieddate")
private Date lastModifiedDate;
...
create table Person (id integer not null auto_increment, lastmodifieddate datetime, name varchar(255), primary key (id)) ;
insert into Person (lastmodifieddate, name) values (?, ?)
binding parameter [1] as [TIMESTAMP] - <null>
binding parameter [2] as [VARCHAR] - Test
Query query = getSession().createQuery("from " + Person.class.getName());
List<Person> allPersons=query.list();
ReadAll查询:
@MappedSuperclass
public abstract class BaseTable {
@Id
@GeneratedValue
@Column(name = "id")
private int id;
@Column(name = "lastmodifieddate")
private Date lastModifiedDate;
...
create table Person (id integer not null auto_increment, lastmodifieddate datetime, name varchar(255), primary key (id)) ;
insert into Person (lastmodifieddate, name) values (?, ?)
binding parameter [1] as [TIMESTAMP] - <null>
binding parameter [2] as [VARCHAR] - Test
Query query = getSession().createQuery("from " + Person.class.getName());
List<Person> allPersons=query.list();
但当我在控制台中打印列表时,它就更奇怪了。它正在选择带有对象的人员列表
- ID字段=全部0(为什么全部为0?)
- LastModifiedDate=null
- 名称字段具有有效值
- 为什么使用“全部读取”时所有ID字段均为0
- 为什么没有插入LastModifiedDate
@Temporal(TemporalType.DATE)
日期注释
对于ID生成使用策略
@GeneratedValue(strategy=GenerationType.AUTO)
或
或者使用sequance
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "custom_generator")
@SequenceGenerator(name = "custom_generator", sequenceName = "sequance_table")
您还可以在子类中进行属性访问:
public abstract class BaseTable {
protected int id;
protected Date lastModifiedDate;
// ...
}
及
在BaseTable类中尝试此方法
@Temporal(value = TemporalType.TIMESTAMP)
@Column(name = "lastmodifieddate", nullable = false,
columnDefinition = "Timestamp default CURRENT_TIMESTAMP")
@org.hibernate.annotations.Generated(value = GenerationTime.ALWAYS)
public Date getLastModifiedDate( )
{
return this.lastModifiedDate;
}
其中,BaseTable类应具有@MappedSuperclass。实体中必须有一个生成的日期字段
@MappedSuperclass
public abstract class BaseTable {
protected int id;
protected Date lastModifiedDate;
@Id
@GeneratedValue(strategy = GenerationType.AUTO) // For Mysql
// For Oracle or MSSQL @GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id", unique = true, nullable = false)
public int getId()
{
return this.id;
}
@Temporal(value = TemporalType.TIMESTAMP)
@Column(name = "lastmodifieddate", nullable = false,
columnDefinition = "Timestamp default CURRENT_TIMESTAMP")
@org.hibernate.annotations.Generated(value = GenerationTime.ALWAYS)
public Date getLastModifiedDate( )
{
return this.lastModifiedDate;
}
}
数据库中的“lastmodifieddate”是什么类型的?它的日期时间
datetime
。映射正在正确地生成DB表中的列。对于id
,您使用的持久性提供程序是什么?在persistence.xml中。冬眠持续?对不起,我没听懂。我没有任何persistence.xml文件。我使用Spring+Hibernate和注释来映射持久对象。你能告诉我你所说的持久性提供者是什么吗?我尝试了你建议的所有方法,但仍然是一样的。。谢谢。日期仍然没有插入?更新了,没有@MappedSuperclass,但想法相同。如果仍然不工作,那我就无能为力了。。。