@ManyToMany 集合未填充 spring-boot-starter-data-jpa

Question

@ManyToMany 集合在数据加载时未填充，我遇到了问题。我试过 FetchType.LAZY 和 FetchType.EAGER，结果没有任何变化。

当我打印用户对象时，角色集合对象是空的。

用户 [userId=2, firstName=Ajay, lastName=C, email=admin.demo@gmail.com, password=12345, roles=[]]

也尝试通过添加引用的列。但是没用。

请协助。

用户和角色实体如下。

@Entity
@Table(name = "\"ROLE\"",schema="\"PLATFORM_PROD_IOT\"")
public class Role {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="\"ROLE_ID\"")
    private Long roleId;

    @Column(name="\"ROLE_NAME\"")
    private RoleName name;
//Getters and Setters
}

@Entity
@Table(name = "\"USER\"", schema = "\"PLATFORM_PROD_IOT\"", uniqueConstraints = {
     @UniqueConstraint(columnNames = { "\"EMAIL_ID\"" }) })
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Size(min = 1, max = 50)
    @Column(name = "\"USER_ID\"")
    private Long userId;

    @NotBlank
    @Size(min = 3, max = 50)
    @Column(name = "\"FIRST_NAME\"")
    private String firstName;

    @NotBlank
    @Size(min = 3, max = 50)
    @Column(name = "\"LAST_NAME\"")
    private String lastName;

    @NaturalId
    @NotBlank
    @Size(max = 50)
    @Email
    @Column(name = "\"EMAIL_ID\"")
    private String email;

    @NotBlank
    @Size(min = 3, max = 100)
    @Column(name = "\"PASSWORD\"")
    private String password;


    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(name = "\"USER_ROLE_MAPPING\"", schema = "\"\PLATFORM_PROD_IOT\"", joinColumns = @JoinColumn(name = "\"USER_ID\""), inverseJoinColumns = @JoinColumn(name = "\"ROLE_ID\""))
    private Set<Role> roles = new HashSet<>();

//Getters and Setters

}
@Entity
@Table(name = "\"ROLE\"",schema="\"PLATFORM_PROD_IOT\"")
public class Role {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="\"ROLE_ID\"")
    private Long roleId;

    @Column(name="\"ROLE_NAME\"")
    private RoleName name;
//Getters and Setters
}

Answer 1

在 class 角色中尝试。

  @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "USER_ROLE_MAPPING",joinColumns = @JoinColumn(name = "ROLE_ID"), inverseJoinColumns = @JoinColumn(name = "USER_ID""))
    private Set<Role> roles = new HashSet<>();

并且在 class 中，用户将 fetchType 更改为 EAGER。如果它不起作用，请尝试将 table 更改为不同的名称。示例：用户、角色。它不起作用，因为它在 SQL 数据库中具有相同的名称。

@ManyToMany 集合未填充 spring-boot-starter-data-jpa

@ManyToMany collection not populating with spring-boot-starter-data-jpa

spring-boot

spring-boot-jpa