How to solve HHH000346 Error using hibernate 5 and mysql? - mysql

Question

I'm studying restful service and views.
Regarding it, I use mysql and hibernate 5.
My data tables are two and have reference relation.
The problem occurs when I update the primary key.
When I add new one then update existing data in another table (they have reference relation), HHH000346: Error during managed flush occurs.
I already search on google, but I couldn't find the answer.
This is my Entity classes.
#Entity
#Table(name = "users")
#EntityListeners(AuditingEntityListener.class)
public class User {
private long serial;
private String username;
private String password;
public User() {
}
public User(long serial, String username, String password) {
setSerial(serial);
setUsername(username);
setPassword(password);
}
#Column(name = "serial", nullable = false)
#GeneratedValue(strategy = GenerationType.AUTO)
public long getSerial() {
return serial;
}
public void setSerial(long serial) {
this.serial = serial;
}
#Id
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
#Column(name = "password", nullable = false)
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
#Override
public String toString() {
return "serial: " + this.serial + ", username: " + this.username + ", password: " + this.password;
}
}
Entity
#Table(name = "sites")
#EntityListeners(AuditingEntityListener.class)
#IdClass(Site.class)
public class Site implements Serializable{
#ManyToOne
#JoinColumn(name="username",foreignKey=#ForeignKey(name="username"))
private String username;
private String siteURL;
#Id
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
#Id
public String getSiteURL() {
return siteURL;
}
public void setSiteURL(String siteName) {
this.siteURL = siteName;
}
}
And this is class had problem.
public class UserController {
#Autowired
private UserRepository userRepository;
#Autowired
private SiteRepository siteRepository;
private CryptoUtil passwordEncoder = new CryptoUtil();
...
#PutMapping("/users/{username}")
public User updateUser(#PathVariable(value = "username") String username, #Valid #RequestBody User userDetails)
throws ResourceNotFoundException {
User user = userRepository.findById(username)
.orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + username));
List<Site> sites = siteRepository.findByUsername(user.getUsername());
userDetails.setPassword(passwordEncoder.encryptSHA256(userDetails.getPassword()));
final User updateUser = userRepository.save(userDetails);
for (Site site : sites)
{
site.setUsername(userDetails.getUsername());
site = siteRepository.save(site);
}
userRepository.delete(user);
return updateUser;
}
....
}
The for-each statement occurs error.
PLEASE HELP ME

Answer 1

Why did you do this?
#ManyToOne
#JoinColumn(name="username",foreignKey=#ForeignKey(name="username"))
private String username;
It should be:
#ManyToOne
#JoinColumn(name="username",foreignKey=#ForeignKey(name="username"))
private User user;
I'll also suggest you to use the primary key as foreign key.
And you can't have multiple #Id in an entity.