Warning: file_get_contents(/data/phpspider/zhask/data//catemap/8/mysql/72.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
Java 保存数据时级联不工作_Java_Mysql_Hibernate - Fatal编程技术网

Java 保存数据时级联不工作

Java 保存数据时级联不工作,java,mysql,hibernate,Java,Mysql,Hibernate,我有一对一的映射关系 User.java public class User { @Id @SequenceGenerator(name = "userID", sequenceName = "userID") @GeneratedValue(strategy = GenerationType.AUTO, generator = "userID") @Column(name = "id") private Long id; private St

我有一对一的映射关系

User.java

public class User {

    @Id
    @SequenceGenerator(name = "userID", sequenceName = "userID")
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "userID")
    @Column(name = "id")
    private Long id;

    private String firstName;
    private String lastName;

    @Column(unique = true)
    private String username;
    private String password;

    @OneToOne(mappedBy = "user", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinColumn(name = "id")
    private Role role;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Role getRole() {
        return role;
    }

    public void setRole(Role role) {
        this.role = role;
    }

    @Override
    public String toString() {
        return "User [id=" + id + ", firstName=" + firstName + ", lastName="
                + lastName + ", username=" + username + ", password="
                + password + ", role=" + role + "]";
    }

}
Roles.java

public class Role {

    @Id
    @SequenceGenerator(name = "userID", sequenceName = "userID")
    @GeneratedValue(strategy = GenerationType.AUTO, generator = "userID")
    @Column(name = "roleId")
    private Long roleId;

    @OneToOne
    private User user;
    private Integer role;

    public Long getId() {
        return roleId;
    }

    public void setId(Long id) {
        this.roleId = id;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public Integer getRole() {
        return role;
    }

    public void setRole(Integer role) {
        this.role = role;
    }
}
我正设法保存数据

public Long create(User user) {
    Long userID = super.save(user);
    return userID;
}
当我试图保存用户实体时,我看到数据保存如下

用户表:

    id   firstName lastName   usrename   password

     1    hello     hello      hello     hello
角色表:

    roleId      role     user_id

     1          1         NULL
你能告诉我你的用户表之间没有关联吗

我需要用户_id为1而不是NULL

此处,用户表的id未映射到表角色的用户\u id

该角色是关联的所有者,用户的@OneToOne角色根本不需要@JoinColumn:

@Id
@SequenceGenerator(name = "userID", sequenceName = "userID")
@GeneratedValue(strategy = GenerationType.AUTO, generator = "userID")
@Column(name = "id")
private Long id;

@OneToOne(mappedBy = "user", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private Role role;
保存用户时,还需要设置关联的双方:

user.setRole(role);
role.setUser(user);
userDao.create(user);

将mappedBy放在角色实体上,并将其从用户中删除(如果该用户拥有该角色)。我可以知道为什么必须设置双方关联吗。我需要用户作为所有者,角色作为子角色。如果@OnetoOne rolw不需要@JoinColumn?每个双向关联。我需要一个单向的添加方式。如果我添加用户,它应该保存特定用户的角色。是否有可能做到这一点。很抱歉问这些问题。我知道我在问一些愚蠢的问题。你能帮我在这方面有单向级联关联吗。