[英]Class design for domain model with audit trail
This is my DB design: 这是我的数据库设计:
Person
------------------------------------------------
ID UINT NOT NULL,
Name VARCHAR(200) NOT NULL,
DOB DATE NOT NULL,
Email VARCHAR(100) NOT NULL
Person_History
------------------------------------------------
ID UINT NOT NULL,
PersonID UINT NOT NULL,
Name VARCHAR(200) NOT NULL,
DOB DATE NOT NULL,
Email VARCHAR(100) NOT NULL
AuditID UINT NOT NULL
Audit
------------------------------------------------
ID UINT NOT NULL,
UserID UINT NOT NULL, -- Who
AffectedOn DATE NOT NULL, -- When
Comment VARCHAR(500) NOT NULL -- Why
I would like to be able to reuse most of the person code for the person history class, since the properties are duplicated. 我希望能够为人员历史记录类重用大多数人员代码,因为属性是重复的。 With the way it is now, should I be factoring out and encapsulating the person properties?
按照现在的方式,我是否应该考虑并封装人员属性? This way, I can use composition, instead of having to duplicate code between a Person class and a PersonHistory class?
这样,我可以使用组合,而不必在Person类和PersonHistory类之间重复代码?
I believe you should avoid duplicating your DB columns in my opinion it should be: 我认为您应该避免重复数据库列:
Person
------------------------------------------------
ID UINT NOT NULL,
Name VARCHAR(200) NOT NULL,
DOB DATE NOT NULL,
Email VARCHAR(100) NOT NULL
Person_History
------------------------------------------------
ID UINT NOT NULL,
PersonID UINT NOT NULL,
AuditID UINT NOT NULL
Audit
------------------------------------------------
ID UINT NOT NULL,
UserID UINT NOT NULL, -- Who
AffectedOn DATE NOT NULL, -- When
Comment VARCHAR(500) NOT NULL -- Why
In case you're using JPA your classes could be mapped like this: 如果您使用的是JPA,则可以按以下方式映射您的类:
@Entity
@Table(name = "PERSON")
public class Person {
@Id
@Column(name = "ID", unique = true, nullable = false)
private Integer id;
@Column(name = "DOB")
@Temporal(TemporalType.DATE)
private Date birthDate;
@Column(name = "EMAIL")
private String email;
@OneToMany(mappedBy="person", fetch=FetchType.LAZY, cascade=CascadeType.ALL)
private List<PersonHistory> personHistories;
// getters and setters...
}
@Entity
@Table(name = "PERSON_HISTORY")
public class PersonHistory {
@Id
@Column(name = "ID", unique = true, nullable = false)
private Integer id;
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="ID_PERSON", nullable=false)
private Person person;
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="ID_AUDIT", nullable=false)
private Audit audit;
// getters and setters...
}
@Entity
@Table(name = "AUDIT")
public class Audit {
@Id
@Column(name = "ID", unique = true, nullable = false)
private Integer id;
@Column(name = "AFFECTED_ON")
@Temporal(TemporalType.DATE)
private Date affectedOn;
@Column(name = "COMMENT")
private String comment;
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="ID_USER", nullable=false)
private User user;
// getters and setters...
}
So in your object model you will be able to access Person data from Person History. 因此,在对象模型中,您将能够从“人员历史记录”中访问“人员”数据。
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