java springboot中的多对多和一对多映射

Question

我有这 3 个实体，我想将它们转换为具有关系的表

- - - 用户 - - -

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString

@Entity
@Table(name = "user")
public class User {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="user_Id")
    private int userId;
    @Column(name="name")
    private String name;
    @Column(name="lastname")
    private String lastname;
    @Column(name="email")
    private String email;
    @Column(name="password")
    private String password;
    @Column(name="isActive")
    private boolean isActive;
    @Column(name="lastActive")
    private String lastActive;
    @Column(name="createdDate")
    private String createdDate;
    @Column(name="isBlocked")
    private boolean isBlocked;
    
    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "institution_id", nullable = false)
    private Institution institution;
    
    @ManyToMany(mappedBy = "users")
    private Set<Role> roles;

}

- - -角色 - - -

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString

@Entity
@Table(name = "role")
public class Role {
    
    @Id
    @GeneratedValue
    @Column(name="role_Id")
    private int roleId;
    @Column(name="name")
    private String name;
    @Column(name="description")
    private String description;
    @ManyToMany(cascade = CascadeType.ALL)
    @JoinTable
    private Set<User> users;

}

- - -机构 - - -

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString

@Entity
@Table(name = "institution")
public class Institution {
    @Id
    @GeneratedValue
    @Column(name="institution_Id")
    private int institutionId;
    @Column(name="name")
    private String name;
    @Column(name="type")
    private String type;
    @Column(name="location")
    private String location;
    @OneToMany(mappedBy = "institution", fetch = FetchType.LAZY)
    private Set<User> user;
    
}

但是当我将我的项目作为 java 应用程序运行时，在 mySQL 工作台中没有创建任何表（添加多对多注释后发生错误，它是在我添加之前创建表）。

关于我的代码为什么不起作用的任何想法？
这是我的application.properties

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url = jdbc:mysql://localhost:3306/mydb
spring.datasource.username = root
spring.datasource.password = pass123
spring.jpa.show-sql = true
spring.jpa.hibernate.ddl-auto = update
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
server.port=9090

Answer 1

@OneToMany 不创建表。 @ManyToMany 创建一个表，您必须指定其详细信息，例如：

在用户 class 中：

 @ManyToMany
 @JoinTable(name = "users_roles", 
    joinColumns = { @JoinColumn(name = "user_id") }, 
    inverseJoinColumns = { @JoinColumn(name = "role_id") })
 private Set<Role> roles;

在 class 角色中：

@ManyToMany(mappedBy="roles")
private Set<User> users;