Java 如何在SpringBoot中扩展类而不更改MySQL模式?
例如,我有一个User类,看起来如下所示:Java 如何在SpringBoot中扩展类而不更改MySQL模式?,java,mysql,hibernate,spring-boot,Java,Mysql,Hibernate,Spring Boot,例如,我有一个User类,看起来如下所示: @Entity @Table(name = "users") public class User{ @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "id") private Long id; @NotBlank @Size(max = 4
@Entity
@Table(name = "users")
public class User{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;
@NotBlank
@Size(max = 40)
@Column(name = "name")
private String name;
@NotBlank
@Size(max = 15)
@Column(name = "username")
private String username;
@NaturalId
@NotBlank
@Size(max = 40)
@Email
@Column(name = "email")
private String email;
@NotBlank
@Size(max = 100)
@Column(name = "password")
private String password;
@ManyToMany(fetch = FetchType.LAZY)
@JoinTable(name = "user_roles",
joinColumns = @JoinColumn(name = "user_id"),
inverseJoinColumns = @JoinColumn(name = "role_id"))
private Set<Role> roles = new HashSet<>();
//Constructor
//Getters and Setters
@实体
@表(name=“users”)
公共类用户{
@身份证
@GeneratedValue(策略=GenerationType.IDENTITY)
@列(name=“id”)
私人长id;
@不空白
@尺寸(最大值=40)
@列(name=“name”)
私有字符串名称;
@不空白
@尺寸(最大值=15)
@列(name=“username”)
私有字符串用户名;
@归化
@不空白
@尺寸(最大值=40)
@电子邮件
@列(name=“email”)
私人字符串电子邮件;
@不空白
@尺寸(最大值=100)
@列(name=“password”)
私有字符串密码;
@ManyToMany(fetch=FetchType.LAZY)
@JoinTable(name=“用户角色”,
joinColumns=@JoinColumn(name=“user\u id”),
inverseJoinColumns=@JoinColumn(name=“role\u id”))
私有集角色=新HashSet();
//建造师
//接球手和接球手
我有客户端类:
@Entity
@Table(name = "cliente")
public class Cliente {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;
@Column(name = "empresa")
private String empresa;
@Column(name = "telefono")
private Integer telefono;
@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(unique = true)
private Licencia licencia;
@OneToMany(cascade = {
CascadeType.PERSIST,
CascadeType.REMOVE
} ,fetch = FetchType.EAGER)
@JoinTable(name = "user_cliente",
joinColumns = @JoinColumn(name = "cliente_id"),
inverseJoinColumns = @JoinColumn(name = "user_id"))
private Set<User> users = new HashSet<>();
public Cliente(String empresa, Integer telefono) {
this.empresa = empresa;
this.telefono = telefono;
}
//Constructor
//Getters and Setters
@实体
@表(name=“客户”)
公共类客户{
@身份证
@GeneratedValue(策略=GenerationType.IDENTITY)
@列(name=“id”)
私人长id;
@列(name=“empresa”)
私人字符串empresa;
@列(name=“telefono”)
私人整数电话;
@OneToOne(级联=级联类型.ALL)
@JoinColumn(unique=true)
私人许可证;
@OneToMany(级联={
cascade type.PERSIST,
级联类型。删除
},fetch=FetchType.EAGER)
@JoinTable(name=“user\u cliente”,
joinColumns=@JoinColumn(name=“cliente_id”),
inverseJoinColumns=@JoinColumn(name=“user\u id”))
private Set users=new HashSet();
公共客户(String empresa、Integer telefono){
this.empresa=empresa;
this.telefono=telefono;
}
//建造师
//接球手和接球手
现在,我想做的是Client类来扩展User类,这样我就可以添加一个具有名称、用户名、电子邮件等的客户端。但是我希望MySQL中有两个单独的表,一个用于用户及其属性,另一个仅用于具有客户端信息的客户端,如电话或公司。问题是当我在Clie中扩展User类时nt类,MySQL数据库更新并在用户表中创建电话、公司等字段。如何避免这种情况?使用
@MappedSuperclass
:
@MappedSuperclass
public class BaseEntity {
// here you can add common fields for your entities
}
@Entity
@Table(name = "cliente")
public class Cliente extends BaseEntity {
// client specific fields here
}
然后从中延伸:
@Entity
public class User extends BaseEntity {
// user specific fields goes here
}
和客户端
:
@MappedSuperclass
public class BaseEntity {
// here you can add common fields for your entities
}
@Entity
@Table(name = "cliente")
public class Cliente extends BaseEntity {
// client specific fields here
}
有关更多信息,请阅读使用
@MappedSuperclass
:
@MappedSuperclass
public class BaseEntity {
// here you can add common fields for your entities
}
@Entity
@Table(name = "cliente")
public class Cliente extends BaseEntity {
// client specific fields here
}
然后从中延伸:
@Entity
public class User extends BaseEntity {
// user specific fields goes here
}
和客户端
:
@MappedSuperclass
public class BaseEntity {
// here you can add common fields for your entities
}
@Entity
@Table(name = "cliente")
public class Cliente extends BaseEntity {
// client specific fields here
}
欲了解更多信息,请阅读,但没有创建超类的方法无法做到这一点?我已经这样做了,但仍在更改sql表。知道原因吗?它不可复制。请更新您的问题,以便我们可以看到您所做的事情,但没有创建超类的方法无法做到这一点?我已经这样做了,但仍在更改sql选项卡你知道为什么吗?这是不可复制的。请更新你的问题,这样我们就可以看到你做了什么