Java 休眠正确映射映射
我在Hibernate中有以下几个类Java 休眠正确映射映射,java,hibernate,jakarta-ee,Java,Hibernate,Jakarta Ee,我在Hibernate中有以下几个类 @Entity @Table(name="MODEL") public class Model { @Id @GeneratedValue(generator="increment") @GenericGenerator(name="increment", strategy = "increment") Long id; @ElementCollection(fetch=FetchType.EAGER) @C
@Entity
@Table(name="MODEL")
public class Model {
@Id
@GeneratedValue(generator="increment")
@GenericGenerator(name="increment", strategy = "increment")
Long id;
@ElementCollection(fetch=FetchType.EAGER)
@CollectionTable
(
name="DEVICE_LiCENSE_ATTRIBUTE",
joinColumns=@JoinColumn(name="DEVICE")
)
@MapKeyJoinColumn(name="LICENSE_ATTRIBUTE",nullable=false)
Map<String,SoftwareLicense> softwareLicenses = new HashMap<String, SoftwareLicense>();
}
现在,当我运行Hibernate时,真正需要构建表
create table DEVICE_LiCENSE_ATTRIBUTE (DEVICE bigint not null, Type varchar(255) not null, VALUE varchar(255) not null, softwareLicenses_KEY varchar(255), primary key (DEVICE, softwareLicenses_KEY))
create table DMS_DEVICE_MODEL (id bigint not null, DESCRIPTION varchar(255) not null, DISPLAYNAME varchar(255) not null, UNIQUENAME varchar(255) not null, primary key (id), unique (UNIQUENAME))
我的问题发生在创建设备\u许可证\u属性
表时
只需查看设备\许可证\属性表:
softwareLicenses\u KEY varchar(255)
可为空,Hibernate尝试在可为空的行上创建复合主键
primary key (DEVICE, softwareLicenses_KEY)
它在某些数据库(HSQLDB)上工作,但将代码切换到另一个环境(MSSQL2008)会给我带来一个错误
Cannot define PRIMARY KEY constraint on nullable column in table 'DEVICE_LICENSE_ATTRIBUTE'
我怎样才能解决这个问题 我的映射错误:
映射它的正确方法是使用映射列属性:
@ElementCollection(fetch=FetchType.EAGER)
@MapKeyColumn(name = "LICENSE_NAME", insertable = false, updatable = false)
@CollectionTable
(
name="DEVICE_LiCENSE_ATTRIBUTE",
joinColumns=@JoinColumn(name="DEVICE")
)
@MapKeyJoinColumn(name="LICENSE_ATTRIBUTE",nullable=false)
Map<String,SoftwareLicense> softwareLicenses = new HashMap<String, SoftwareLicense>();
@ElementCollection(fetch=FetchType.EAGER)
@MapKeyColumn(name=“LICENSE\u name”,insertable=false,updateable=false)
@收集表
(
name=“设备\许可证\属性”,
joinColumns=@JoinColumn(name=“DEVICE”)
)
@MapKeyJoinColumn(name=“LICENSE\u ATTRIBUTE”,nullable=false)
Map softwareLicenses=新建HashMap();
回家对某人有帮助
@ElementCollection(fetch=FetchType.EAGER)
@MapKeyColumn(name = "LICENSE_NAME", insertable = false, updatable = false)
@CollectionTable
(
name="DEVICE_LiCENSE_ATTRIBUTE",
joinColumns=@JoinColumn(name="DEVICE")
)
@MapKeyJoinColumn(name="LICENSE_ATTRIBUTE",nullable=false)
Map<String,SoftwareLicense> softwareLicenses = new HashMap<String, SoftwareLicense>();