JPA外键约束冲突不能插入Null

【问题标题】：JPA Foreign Key constraint violation cannot insert NullJPA外键约束冲突不能插入Null
【发布时间】：2015-10-02 20:49:28
【问题描述】：

我有一个简单的用户和角色实体，具有一对多映射。一位用户拥有许多角色。尝试保存用户实体时出现错误。我在调用persist之前设置角色对象用户。

以下是实体的快照。

用户：

package com.petpe.ejbadmin.entity;

import java.io.Serializable;
import java.util.Date;
import java.util.Set;

import javax.annotation.Generated;
import javax.persistence.Basic;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;


@Entity
@Table(name = "users")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "User.findAll", query = "SELECT u FROM User u"),
    @NamedQuery(name = "User.findByUsernameandPassword", query = "SELECT u FROM User u WHERE u.username = :username AND u.password = :password"),
    @NamedQuery(name = "User.findByUserfirstname", query = "SELECT u FROM User u WHERE u.userfirstname = :userfirstname"),
    @NamedQuery(name = "User.findByUserlastname", query = "SELECT u FROM User u WHERE u.userlastname = :userlastname"),
    @NamedQuery(name = "User.findByPhonenumber", query = "SELECT u FROM User u WHERE u.phonenumber = :phonenumber"),
    @NamedQuery(name = "User.findByEmail", query = "SELECT u FROM User u WHERE u.email = :email"),
    @NamedQuery(name = "User.findByErpid", query = "SELECT u FROM User u WHERE u.erpid = :erpid"),
    @NamedQuery(name = "User.findByBuyerid", query = "SELECT u FROM User u WHERE u.buyerid = :buyerid"),
    @NamedQuery(name = "User.findByCreatedDate", query = "SELECT u FROM User u WHERE u.createdDate = :createdDate"),
    @NamedQuery(name=  "User.findByfirstletter",query="SELECT u FROM User u join fetch u.RoleSet ur WHERE LOWER(u.userfirstname) LIKE :firstname"),
    @NamedQuery(name=  "User.findallusers",query="From User u join fetch u.RoleSet ur")})
public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Basic(optional = true)
    @Column(name = "USER_ID")
    private Integer userId;
    @Size(max = 120)
    @Column(name = "USERNAME")
    private String username;
    @Size(max = 60)
    @Column(name = "USERFIRSTNAME")
    private String userfirstname;
    @Size(max = 60)
    @Column(name = "USERLASTNAME")
    private String userlastname;
    @Size(max = 50)
    @Column(name = "PASSWORD")
    private String password;
    @Size(max = 20)
    @Column(name = "PHONENUMBER")
    private String phonenumber;
    // @Pattern(regexp="[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?", message="Invalid email")//if the field contains email address consider using this annotation to enforce field validation
    @Size(max = 50)
    @Column(name = "EMAIL")
    private String email;
    @Size(max = 250)
    @Column(name = "ERPID")
    private String erpid;
    @Size(max = 250)
    @Column(name = "BUYERID")
    private String buyerid;
    @Basic(optional = false)
    @NotNull
    @Column(name = "CREATED_DATE")
    @Temporal(TemporalType.DATE)
    private Date createdDate;
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "user", fetch = FetchType.LAZY)
    private Set<Role> RoleSet;

    public User() {
    }

    public User(Integer userId) {
        this.userId = userId;
    }

    public User(Integer userId, Date createdDate) {
        this.userId = userId;
        this.createdDate = createdDate;
    }

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public String getUsername() {
        return username;
    }

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

    public String getUserfirstname() {
        return userfirstname;
    }

    public void setUserfirstname(String userfirstname) {
        this.userfirstname = userfirstname;
    }

    public String getUserlastname() {
        return userlastname;
    }

    public void setUserlastname(String userlastname) {
        this.userlastname = userlastname;
    }

    public String getPassword() {
        return password;
    }

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

    public String getPhonenumber() {
        return phonenumber;
    }

    public void setPhonenumber(String phonenumber) {
        this.phonenumber = phonenumber;
    }

    public String getEmail() {
        return email;
    }

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

    public String getErpid() {
        return erpid;
    }

    public void setErpid(String erpid) {
        this.erpid = erpid;
    }

    public String getBuyerid() {
        return buyerid;
    }

    public void setBuyerid(String buyerid) {
        this.buyerid = buyerid;
    }

    public Date getCreatedDate() {
        return createdDate;
    }

    public void setCreatedDate(Date createdDate) {
        this.createdDate = createdDate;
    }

    @XmlTransient
    public Set<Role> getRoleSet() {
        return RoleSet;
    }

    public void setRoleSet(Set<Role> RoleSet) {
        this.RoleSet = RoleSet;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (userId != null ? userId.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof User)) {
            return false;
        }
        User other = (User) object;
        if ((this.userId == null && other.userId != null) || (this.userId != null && !this.userId.equals(other.userId))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "[ userId=" + userId + " ]";
    }

}

角色：

/* * 要更改此许可标头，请在项目属性中选择许可标头。 * 要更改此模板文件，请选择工具 |模板 * 并在编辑器中打开模板。 */

package com.petpe.ejbadmin.entity;

import java.io.Serializable;

import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import javax.xml.bind.annotation.XmlRootElement;


@Entity
@Table(name = "user_roles")
@XmlRootElement
public class Role implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "ROLEID")
    private Integer roleid;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 30)
    @Column(name = "ROLENAME")
    private String rolename;
    @JoinColumn(name = "USER_ID", referencedColumnName = "USER_ID")
    @ManyToOne( fetch = FetchType.LAZY)
    private User user;

    public Role() {
    }

    public Role(String rolename) {
        this.rolename = rolename;
    }

    public Role(Integer roleid, String rolename) {
        this.roleid = roleid;
        this.rolename = rolename;
    }

    public User getUser() {
        return user;
    }

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

    public Integer getRoleid() {
        return roleid;
    }

    public void setRoleid(Integer roleid) {
        this.roleid = roleid;
    }

    public String getRolename() {
        return rolename;
    }

    public void setRolename(String rolename) {
        this.rolename = rolename;
    }



    @Override
    public int hashCode() {
        int hash = 0;
        hash += (roleid != null ? roleid.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Role)) {
            return false;
        }
        Role other = (Role) object;
        if ((this.roleid == null && other.roleid != null) || (this.roleid != null && !this.roleid.equals(other.roleid))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "[ roleid=" + roleid + " ]";
    }

}

错误：

1.Cannot insert the value NULL into column 'USER_ID', table 'pedb.pedb.user_roles'; column does not allow nulls. INSERT fails.
2.could not insert: [com.petpe.ejbadmin.entity.Role]
3.org.hibernate.exception.ConstraintViolationException: could not insert: [com.petpe.ejbadmin.entity.Role]
4.javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: could not insert: [com.petpe.ejbadmin.entity.Role]

设置和持久化代码：

public boolean AddorModifyUser(UserAdminDTO udato) {

        User usr=this.populateUserobj(udato);
        pet_em.persist(usr);

        return true;
    }

public User populateUserobj(UserAdminDTO udto)
    {
        User usr=new User();

        usr.setBuyerid(udto.getbuyerid());
        usr.setCreatedDate(new Date());
        usr.setEmail(udto.getEmail());
        usr.setErpid(udto.geterpid());
        usr.setPassword(udto.getPassword());
        usr.setPhonenumber(udto.getPhoneNumber());
        usr.setUserfirstname(udto.getFirstName());
        usr.setUserlastname(udto.getLastName());
        usr.setUsername(udto.getUserName());
        for(Role r: udto.getRole())
        {
            Set<Role> RoleSet=new HashSet<>();
            RoleSet.add(r);     
            usr.setRoleSet(RoleSet);
        }
        return usr;
    }

表格布局：

【问题讨论】：

  • 试试 (mappedBy = "user") 而不是 "userId"
  • 为什么在用户进入数据库之前尝试持久化 user_roles？这行不通
  • 我没有在用户之前保留角色。正如我在帖子中所说，我在用户实体中设置了几个角色对象并持久化用户。
  • 您是否将 mappedBy 更改为 "user" 而不是 "userId" ？你总是有同样的错误吗？
  • 嗨，比拉尔。买家 ID 不是身份列。用户 ID 是身份列，我没有设置它。数据库很好，因为如果我不在用户中添加角色，它允许插入用户实体。

标签： java hibernate jpa


【解决方案1】：

所以你在角色表中的USER_ID 上有一个NOT NULL 约束。持久化时（即使是级联关系），外键（或实体关系）不会自动设置自己。

很可能在创建Role 时，您没有设置User，因此在持久化时，提供者不知道USER_ID 是什么，因此尝试在数据库中将其设置为null，即违反了 db 架构。

您需要做的就是为每个Role 设置User

Set<Role> RoleSet=new HashSet<>();
for(Role r: udto.getRole())
{
    r.setUser(usr);   // <------
    RoleSet.add(r);     
}
usr.setRoleSet(RoleSet);

还要注意Set 是在循环外创建的

并且...但是...等待...

你还没有走出困境。以上将解决错误，但您还有另一个问题。它很微妙，肯定会导致很难找到错误。

您正在生成Role id。

@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Integer roleid;

所以你在创建角色的时候不要设置

Set<Role> roles = new HashSet<>();
Role userRole = new Role("USER");
userRole.setUser(user);
roles.add(userRole);
Role coolRole = new Role("COOL_GUY");
coolRole.setUser(user);
roles.add(coolRole);
user.setRoleSet(roles);

看起来没有问题，但错误在hashCode中

@Override
public int hashCode() {
    int hash = 0;
    hash += (roleid != null ? roleid.hashCode() : 0);
    return hash;
}

hashCode 仅由roleId 组成。但是您没有设置roleId，因为它应该被生成。因此，当您将角色添加到Set 时，它们都具有相同的hashCode，因此您最终只能在Set 中添加一个Role，因为Set 中的对象不能具有相同的hashCode .

要解决此问题，您只需将hashCode 更改为也包括rolename。

在测试时，我只是让 Netbeans 生成 hashCode 和 equals。结果如下。

@Override
public int hashCode() {
    int hash = 7;
    hash = 31 * hash + Objects.hashCode(this.roleid);
    hash = 31 * hash + Objects.hashCode(this.rolename);
    return hash;
}

@Override
public boolean equals(Object obj) {
    if (obj == null) {
        return false;
    }
    if (getClass() != obj.getClass()) {
        return false;
    }
    final Role other = (Role) obj;
    if (!Objects.equals(this.roleid, other.roleid)) {
        return false;
    }
    if (!Objects.equals(this.rolename, other.rolename)) {
        return false;
    }
    return true;
}

这应该可以修复错误。

【讨论】：

    猜你喜欢
    • 2018-04-25
    • 1970-01-01
    • 1970-01-01
    • 2015-05-17
    • 2017-12-31
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    相关资源
    最近更新 更多
    热门标签
    Java Python linux javascript Mysql C# Docker 算法 前端 SpringBoot Redis Vue spring 设计模式 .net core .net kubernetes c++ 数据库 数据结构 大数据 js 机器学习 微服务 Android Go 程序员 面试 JVM ASP.net core 云原生 人工智能 后端 PHP git CSS golang k8s Nginx Django mybatis 深度学习 多线程 React 架构 devops 爬虫 云计算 Spring Boot LeetCode