英文:
Add foreign key using hibernate and jpa
问题
以下是翻译好的内容：
这些是我的类：
@Entity
@Table(name="assessment")
public class AssesmentProperties {
@Id
@Column(name="AssessmentId")
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long AssessmentId;
@Column(unique=true,nullable=false)
private String AssessmentName;
private String AssessmentLevel;
private String Specialization;
private int time;
private String keywords;
private int NoOfSections;
//getters and setters
}
@Embeddable
public class SettingsPrimary implements Serializable {
private Long AssessmentId;
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long Section;
//getters and setters
}
@Entity
@Table(name="section")
public class SectionProperties {
@EmbeddedId
private SettingsPrimary PrimaryKey;
private String SectionType;
private int Weightage;
private int time;
private int NoOfQuestions;
//getters and setters
}
在表格 section 中，我需要将 assessment_id 创建为指向 assessment 表的外键，并在删除时设置级联操作。我尝试了不同的方法，但都没有成功。
英文:
Those are my classes:
@Entity
@Table(name="assessment")
public class AssesmentProperties {
@Id
@Column(name="AssessmentId")
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long AssessmentId;
@Column(unique=true,nullable=false)
private String AssessmentName;
private String AssessmentLevel;
private String Specialization;
private int time;
private String keywords;
private int NoOfSections;
//getters and setters
}
@Embeddable
public class SettingsPrimary implements Serializable {
private Long AssessmentId;
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long Section;
//getters and setters
}
@Entity
@Table(name="section")
public class SectionProperties {
@EmbeddedId
private SettingsPrimary PrimaryKey;
private String SectionType;
private int Weightage;
private int time;
private int NoOfQuestions;
//getters and setters
}
In the table section I need to create assessment_id as FK to assessment table and set cascade on delete. I have tried to do it with different ways but without success.
答案1
得分: 1
或许这能帮助你。
@Entity
@Table(name="section")
public class SectionProperties {
@Id
private Long PrimaryKey;
@ManyToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "assessment_id", referencedColumnName="AssessmentId")
private AssesmentProperties AssesmentProperties;
private String SectionType;
private int Weightage;
private int time;
private int NoOfQuestions;
// getters and setters
}
我将SectionProperties的id更改为Long，并将AssessmentProperties映射为一个ManyToOne属性。这样，每当与某个Section绑定的AssessmentProperties被删除时，相关的SectionProperties也将被删除。
英文:
Maybe this could help you.
@Entity
@Table(name="section")
public class SectionProperties {
@Id
private Long PrimaryKey;
@ManyToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "assessment_id", referencedColumnName="AssessmentId")
private AssesmentProperties AssesmentProperties;
private String SectionType;
private int Weightage;
private int time;
private int NoOfQuestions;
//getters and setters
}
I changed the SectionProperties id to a Long and mapped the AssessmentProprties into a ManytoOne prop.
This way, always that a AssessmentProperties binded to a Section will be deleted, the associated SectionProperties will too.
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