java 如何使用带有 JBOSS 工具的休眠在数据库中添加新记录？
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How can I add new record in database using hibernate with JBOSS Tool?
提问by Jyun Wei Chen
I am using Eclipse and JBOSS Tool to generate hibernate class from MySQL. The salary table have composite key, one is FK(userId), one is AUTO_INCREMENT. So JBOSS Tool generated Salary and User class, it also generated SalaryId class. I have added cascade in getSalaries method of User class, but when I tried to save the new user, I always get the exception: org.hibernate.exception.ConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails
我正在使用 Eclipse 和 JBOSS 工具从 MySQL 生成休眠类。工资表有复合键，一个是FK(userId)，一个是AUTO_INCREMENT。所以JBOSS Tool 生成了Salary 和User 类，它也生成了SalaryId 类。我在 User 类的 getSalaries 方法中添加了级联，但是当我尝试保存新用户时，总是出现异常： org.hibernate.exception.ConstraintViolationException：无法添加或更新子行：外键约束失败
Does anyone have any idea to help me solve this problem? Thanks all~
有没有人有任何想法可以帮助我解决这个问题？谢谢大家~
Below are my table structure:
下面是我的表结构：
CREATE TABLE IF NOT EXISTS `salary` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`userId` int(11) NOT NULL,
`amount` int(11) NOT NULL,
`comingDate` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id`,`userId`),
KEY `userId` (`userId`)
)
Below are my generated class: [User class]
下面是我生成的类：[用户类]
@Entity
@Table(name = "user", catalog = "lab")
public class User implements java.io.Serializable {
private Integer id;
private String name;
private String password;
private String email;
private Set<Salary> salaries = new HashSet<Salary>(0);
public User() {
}
public User(String name, String password, String email, Set<Salary> salaries) {
this.name = name;
this.password = password;
this.email = email;
this.salaries = salaries;
}
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "id", unique = true, nullable = false)
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
@Column(name = "name", nullable = false, length = 100)
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
@Column(name = "password", nullable = false, length = 100)
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
@Column(name = "email", nullable = false, length = 50)
public String getEmail() {
return this.email;
}
public void setEmail(String email) {
this.email = email;
}
@OneToMany(fetch = FetchType.LAZY, mappedBy = "user", cascade = CascadeType.ALL)
public Set<Salary> getSalaries() {
return this.salaries;
}
public void setSalaries(Set<Salary> salaries) {
this.salaries = salaries;
}
}
[Salary class]
【薪资等级】
@Entity
@Table(name = "salary", catalog = "lab")
public class Salary implements java.io.Serializable {
private SalaryId id;
private User user;
private int amount;
private Date comingDate;
public Salary() {
}
public Salary(SalaryId id, User user, int amount) {
this.id = id;
this.user = user;
this.amount = amount;
}
public Salary(SalaryId id, User user, int amount, Date comingDate) {
this.id = id;
this.user = user;
this.amount = amount;
this.comingDate = comingDate;
}
@EmbeddedId
@AttributeOverrides({
@AttributeOverride(name = "id", column = @Column(name = "id", nullable = false)),
@AttributeOverride(name = "userId", column = @Column(name = "userId", nullable = false)) })
public SalaryId getId() {
return this.id;
}
public void setId(SalaryId id) {
this.id = id;
}
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "userId", nullable = false, insertable = false, updatable = false)
public User getUser() {
return this.user;
}
public void setUser(User user) {
this.user = user;
}
@Column(name = "amount", nullable = false)
public int getAmount() {
return this.amount;
}
public void setAmount(int amount) {
this.amount = amount;
}
@Temporal(TemporalType.TIMESTAMP)
@Column(name = "comingDate", nullable = false, length = 19)
public Date getComingDate() {
return this.comingDate;
}
public void setComingDate(Date comingDate) {
this.comingDate = comingDate;
}
}
Below is auto generated by JBOSS Tool:
以下是 JBOSS 工具自动生成的：
[SalaryId class]
[SalaryId 类]
@Embeddable
public class SalaryId implements java.io.Serializable {
private int id;
private int userId;
public SalaryId() {
}
public SalaryId(int id, int userId) {
this.id = id;
this.userId = userId;
}
@Column(name = "id", nullable = false)
public int getId() {
return this.id;
}
public void setId(int id) {
this.id = id;
}
@Column(name = "userId", nullable = false)
public int getUserId() {
return this.userId;
}
public void setUserId(int userId) {
this.userId = userId;
}
public boolean equals(Object other) {
if ((this == other))
return true;
if ((other == null))
return false;
if (!(other instanceof SalaryId))
return false;
SalaryId castOther = (SalaryId) other;
return (this.getId() == castOther.getId())
&& (this.getUserId() == castOther.getUserId());
}
public int hashCode() {
int result = 17;
result = 37 * result + this.getId();
result = 37 * result + this.getUserId();
return result;
}
}
[Main class]
【主课】
transaction = session.beginTransaction();
SalaryId salaryId = new SalaryId();
Set<Salary> salaries = new HashSet<Salary>();
User user = new User();
user.setName("JW");
user.setPassword("123456");
user.setEmail("[email protected]");
salaries.add(new Salary(salaryId, user, 10000));
user.setSalaries(salaries);
session.save(user);
transaction.commit();
回答by zato
Try to do like this:
尝试这样做：
transaction = session.beginTransaction();
SalaryId salaryId = new SalaryId();
Set<Salary> salaries = new HashSet<Salary>();
User user = new User();
user.setName("JW");
user.setPassword("123456");
user.setEmail("[email protected]");
session.save(user);
salaries.add(new Salary(salaryId, user, 10000));
//user.setSalaries(salaries);
transaction.commit();
