无法删除或更新父行：删除具有引用的实体时外键约束失败

Question

我想删除一个引用“Authority”实例的“UserRegistration”实例。通过存储库删除“UserRegistration”实例时，出现以下错误： “无法删除或更新父行：外键约束失败 (seprojekt.authorities, CONSTRAINT authorities_ibfk_1 FOREIGN KEY (userid) REFERENCES users (id))” 删除“UserRegistration”实例时是否有可能删除引用的实体？我在“UserRegistration”中使用 Cascadetype 和 orphanRemoval 进行了尝试，但没有任何反应。

尝试删除实体的方法：

@DeleteMapping
public boolean deleteUser(@RequestParam String username) {
    Optional<UserRegistration> optUserRegistration = uRepo.findByUsername(username);
    if(optUserRegistration.isPresent()) {
        System.out.println("!!! Authority is: '" + optUserRegistration.get().getAuthority().getAuthority());
        uRepo.delete(optUserRegistration.get());
        return true;
    }
    return false;
}

UserRegistration 类如下所示：

import java.util.List;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.OneToOne;
import javax.persistence.Table;

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonManagedReference;
@Entity
@Table(name = "users")
public class UserRegistration {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
private String username;
@JsonIgnore
private String password;
@JsonIgnore
private boolean enabled;
private Integer profilePicture;
private String email;
@OneToOne(cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "id")
private Authority authority;
@JsonManagedReference
@ManyToMany
@JoinTable(name = "userhasfavorite", joinColumns = @JoinColumn(name = "userid"), inverseJoinColumns = @JoinColumn(name = "channelid"))
private List<Channel> favorites;

public UserRegistration() {
}

public UserRegistration(String email, String username, String password, boolean enabled, int profilePicture) {
    this.email = email;
    this.username = username;
    this.password = password;
    this.enabled = enabled;
    this.profilePicture = profilePicture;
}

public int getId() {
    return id;
}

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

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 boolean getEnabled() {
    return enabled;
}

public void setEnabled(boolean enabled) {
    this.enabled = enabled;
}

public Integer getProfilePicture() {
    return profilePicture;
}

public void setProfilePicture(Integer profilePicture) {
    this.profilePicture = profilePicture;
}

public String getEmail() {
    return email;
}

public void setEmail(String email) {
    this.email = email;
}

public Authority getAuthority() {
    return authority;
}

public void setAuthority(Authority authority) {
    this.authority = authority;
}

public List<Channel> getFavorites() {
    return favorites;
}

public void setFavorites(List<Channel> favorites) {
    this.favorites = favorites;
}
}

权威类看起来像这样：

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.OneToOne;
import javax.persistence.Table;

@Entity
@Table(name = "authorities")
public class Authority {

    @Id
    @Column(name = "userid")
    private int userID;
    private String username;
    private String authority;
    @OneToOne(mappedBy = "authority")
    private UserRegistration user;

    public Authority() {
    }

    public Authority(int userID, String username, String authority) {
        this.userID = userID;
        this.username = username;
        this.authority = authority;
    }

    public int getUserID() {
        return userID;
    }

    public void setUserID(int userID) {
        this.userID = userID;
    }

    public String getUsername() {
        return username;
    }

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

    public String getAuthority() {
        return authority;
    }

    public void setAuthority(String authority) {
        this.authority = authority;
    }

    public UserRegistration getUser() {
        return user;
    }

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

非常感谢您阅读本文。如果需要，请向我询问更多详细信息。

Answer 1

为了让级联工作；您需要反转实体关系定义。级联仅适用于父实体到子实体。我的意思是以下。请将UserRegistration中的authority定义为：

@OneToOne(mappedBy="user", cascade = CascadeType.ALL)
private Authority authority;

和Authority 中的userRegistration 为：

@OneToOne
@MapsId
private UserRegistration user;

我相信这应该可行。查看following 了解更多信息。希望对您有所帮助。