I'm trying to map up an existing database schema using Hibernate+JPA annotations.
One of my entities are mapped like this:
#Entity
#Table(name = "users")
public class User implements Serializable {
#Id
private int department;
#Id
private int userId;
...
And another entity, Group:
#Entity
#Table(name = "groups")
public class Group implements Serializable {
#Id
private int department;
#Id
private int groupId;
...
Group and User should have a many-to-many relationship between them, but the issue is that the join table ("user_group") only has columns "DEPARTMENT, USERID, GROUPID" - i.e. the DEPARTMENT column needs to be used in both joinColumns and inverseJoinColumns:
#ManyToMany(cascade = { CascadeType.ALL })
#JoinTable(
name = "user_groups",
joinColumns = { #JoinColumn(name = "department"), #JoinColumn(name = "groupid") },
inverseJoinColumns = {#JoinColumn(name = "department"), #JoinColumn(name = "userid") }
)
private List<User> groupUsers = new ArrayList<>();
which gives a mapping error - "Repeated column in mapping for entity".
However, it looks like this was/is possible using XML, because this exact example exists in the old Hibernate documentation. But I cannot find any evidence that this ever worked using annotations? I tried with #JoinFormula instead of #JoinColumn, but that does not compile. Is it possible?
Okay, I'm pretty sure it's not possible.
I found a promising workaround:
Create an #Embeddable for the "user_group" table:
#Embeddable
public class UserGroupMembership implements Serializable {
#ManyToOne
#JoinColumnsOrFormulas(
value = {
#JoinColumnOrFormula(column = #JoinColumn(referencedColumnName = "userid", name = "userid")),
#JoinColumnOrFormula(formula = #JoinFormula(referencedColumnName = "department", value = "department"))
})
private User user;
public UserGroupMembership(User user) {
this.user = user;
}
public UserGroupMembership() {
}
public User getUser() {
return user;
}
}
The trick is that #ManyToOne allows you to use #JoinColumnsOrFormulas, so one of the join conditions can be a formula, which I doesn't seem to work for #ManyToMany (the #JoinColumnsOrFormulas annotation is ignored as it expects the join columns to be part of the #JoinTable annotation).
The UserGroupMemberships are then mapped as a ElementCollection:
#ElementCollection
#CollectionTable(name = "user_group", joinColumns = {
#JoinColumn(name = "department", referencedColumnName = "department"),
#JoinColumn(name = "groupid", referencedColumnName = "groupid")
})
#OrderColumn(name = "seq", nullable = false)
private List<UserGroupMemberships> groupUsers = new ArrayList<>();
This only works right now for a unidirectional many-to-many relationship.
Related
I currently have a problem with this Relationship, I have tried everything I saw on the internet. Still, I get this error: ERROR: column roles0_.user_id does not exist.
I have a boot app that has spring security, and I need to login using users from PostgreSQL database.
But I just can't get the relation between the user and the Role to work.
Here are Entity classes:
#Data
#Entity
#Table(name="user",schema = "public")
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "user_id")
private Integer id;
#Column(unique = true)
private String username;
private String password;
private boolean enabled;
#OneToMany(mappedBy = "user", fetch = FetchType.EAGER)
private List<Role> roles;
}
#Data
#Entity
#Table(name="role",schema = "public")
public class Role {
#Id
#Column(name="role_id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String name;
#ManyToOne()
#JoinColumn(name ="user_id")
private User user;
}
The database looks fine, I looked at the column names, etc. I don't know what to do to get rid of this error. I have the user table, and another table named roles, which include id and name, 2 inputs, USER and ADMIN...
It seems that the #JoinColumn annotation requires one additional column in the roles table the one with #ManytoOne relation, because when I add the column the error disappears, but when I'm trying to get the role from each user, I get an empty List. The foreign key is set as well, from the roles column to the role_id column from role table.
worked for me this way:
#Entity
#Data
#Table(name = "users")
public class User{
#ManyToMany(fetch = FetchType.EAGER)
#JoinTable(name = "user_roles", joinColumns = {#JoinColumn(name = "user_id", referencedColumnName = "id")},
inverseJoinColumns = {#JoinColumn(name = "role_id", referencedColumnName = "id")})
private List<Role> roles;
}
and then in roles just:
#Entity
#Table(name = "roles")
public class Role{
#ManyToMany(mappedBy = "roles", fetch = LAZY)
private List<User> users;
}
that's if you are ok with third table user_roles (user_id, role_id) which manages the many to many relation
User table :
#OneToMany(cascade = CascadeType.ALL, mappedBy = "user", fetch = FetchType.EAGER)
private List<Role> roles;
Role table :
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "user_id")
private User user;
I have a bidirectional many-to-many relationship between a Role and Scope. Creating both entities and even their childs with the help of CascadeType.PERSIST is easy and straightforward.
The Role entity is simples as that:
#Entity
#Table(uniqueConstraints = #UniqueConstraint(name = "role_name", columnNames = "name"))
public class Role {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private long id;
private String name;
#ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.PERSIST, mappedBy = "roles")
private Set<Scope> scopes;
}
And the Scope:
#Entity
#Table(uniqueConstraints = #UniqueConstraint(name = "scope_name", columnNames = "name"))
public class Scope {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private long id;
private String name;
#JoinTable(name = "role_scopes", joinColumns = #JoinColumn(name = "scope_id"), inverseJoinColumns = #JoinColumn(name = "role_id"))
#ManyToMany(cascade = CascadeType.REMOVE)
private Set<Role> roles;
}
Their repositories are simply CrudRepository extensions:
public interface RoleRepository extends CrudRepository<Role, Long> {}
public interface ScopeRepository extends CrudRepository<Scope, Long> {}
The following snippet exemplifies the entities insertion:
Role adminRole = roleRepository.save(new Role("ADMIN"));
Scope allReadScope = scopeRepository.save(new Scope("all.read"));
Scope allWriteScope = scopeRepository.save(new Scope("all.write"));
Role and Scope can be both automatically easily persisted with the help of the CascadeType.PERSIST, as follows:
Role managedRole = roleRepository.save(new Role("ADMIN", new Scope("all.read"), new Scope("all.write")));
However... Updating managedRole leads to org.hibernate.PersistentObjectException: detached entity passed to persist exception:
managedRole.getScopes().remove(allReadScope);
roleRepository.save(managedRole); // PersistentObjectException!
I tried modifying the Role::scopes's CascadeType to also include DETACH, MERGE and/or REFRESH with no success. How do we get around this?
Most likely you face the problem, because you don't maintain both sides of the relationship in the bidirectional mapping. Lets say in Role:
void add(Scope scope) {
this.scopes.add(scope);
scope.getRoles().add(this);
}
To be honest with you, I'd resign fully from bidirectional mapping. Maintaining this is a real nightmare.
I am a newbie to the Spring boot (but worked in Laravel). I am facing a problem of cyclic redundancy in #ManyToMany relation. Let's go through the scenario -
What response I ma getting (fetching user's list which has many to many relationships with roles) -
Following is the ER-diagram of associated tables to manage many to many relationship between users and roles table.
User entity class has following code -
#Entity
#Where(clause = "deleted_at IS NULL")
#SQLDelete(sql = "UPDATE users SET deleted_at = CURRENT_TIMESTAMP WHERE id = ?", check = ResultCheckStyle.COUNT)
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#Table(name = "users")
#JsonIgnoreProperties(
value = {"createdAt", "updatedAt", "deletedAt"}
)
public class User {
#Id
#Column(name = "id", updatable = false, nullable = false)
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#Column(name = "name", nullable = false)
#NotBlank(message = "Name field can not be empty")
private String name;
.....
.....
.....
#ManyToMany(targetEntity = Role.class, fetch = FetchType.EAGER)
#JoinTable(name = "user_roles",joinColumns = #JoinColumn(name = "user_id"),
inverseJoinColumns = #JoinColumn(name = "role_id"))
private Set<Role> roles;
}
And Role entity is as follows -
#Entity
#Table(name = "roles")
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#SQLDelete(sql = "UPDATE roles SET deleted_at = CURRENT_TIMESTAMP WHERE id = ?", check = ResultCheckStyle.COUNT)
#Where(clause = "deleted_at IS NULL")
#JsonIgnoreProperties(
value = {"createdAt", "updatedAt", "deletedAt"}
)
public class Role {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id", updatable = false, nullable = false)
private long id;
#Column(name = "title")
#NotBlank(message = "Title field must be not null")
private String title;
......
......
......
#OneToMany(targetEntity = User.class, fetch = FetchType.EAGER)
#JoinTable(name = "user_roles",joinColumns = #JoinColumn(name = "role_id"),
inverseJoinColumns = #JoinColumn(name = "user_id"))
private List<User> users;
}
How to solve this problem? What I am doing wrong here?
Since you are fetching the list directly. You will have to mention the annotation #JsonIgnore everywhere you have mapping specified. By everywhere I don't mean literally everywhere. Just use the annotation and see how it works.
Edit -> Just do it in roles table where you have mapped it to the user table. It will then skip the user mapping while fetching the data.
#JsonIgnore
private List<User> users;
You could annotate users within Role with #JsonBackReference.
Easiest would probably be to annotate the List<T>'s with a #JsonIgnoreProperties annotation to break the cyclic dependencies.
#JsonIgnoreProperties("users")
private List<Role> roles;
#JsonIgnoreProperties("roles")
private List<User> users;
I'm trying to figure out what I'm doing wrong with this, but I'm learning hibernate annotations and creating a simple library system. Basically, a book gets checked out by a person, and eventually checked in. Here's how I have it configured:
#Entity
#Table
public class Book {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(nullable = false, unique = true)
private long barcode;
#Column(nullable = false)
private String name;
#OneToMany
#JoinTable(name = "checkoutsession", joinColumns = { #JoinColumn(name = "book") }, inverseJoinColumns = { #JoinColumn(name = "id")})
private List<CheckOutSession> checkOutSessions;
}
#Entity
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#Column(nullable = false, unique = true)
private long barcode;
#Column(name = "firstname")
private String firstName;
#Column(name = "lastname")
private String lastName;
#OneToMany
#JoinTable(name = "checkoutsession", joinColumns = { #JoinColumn(name = "user") }, inverseJoinColumns = { #JoinColumn(name = "id")})
private List<CheckOutSession> checkOutSessions;
}
#Entity
#Table(name = "checkoutsession", uniqueConstraints = {#UniqueConstraint(columnNames={"book", "checkIn"})})
public class CheckOutSession {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#ManyToOne
#JoinColumn(name="book", nullable=false)
private Book book;
#ManyToOne
#JoinColumn(name="user", nullable=false)
private User user;
#Column(nullable = false)
private java.sql.Timestamp checkOut;
#Column
private java.sql.Timestamp checkIn;
}
I can't figure out for the life of me what I've got configured incorrectly.
[EDIT]
when I try to pull a book it is selecting everything from checkoutsession join checkoutsession join user and dies saying "Unknown column checkoutsess1_.check_in in 'field list';
[EDIT2]
A little more context, I have a BookDAO that extends JpaRepository and when I call findAll() is what's creating that query.
[EDIT3]
Rest Class:
#RestController
#RequestMapping("rest/books")
public class BookController {
#RequestMapping(method = RequestMethod.GET)
public List findBooks() {
return bookService.getAllBooks();
}
}
Service:
#Component
public class BookService {
private BookDao bookDao;
public List getAllBooks() {
return bookDao.findAll();
}
#Autowired
public void setBookDao(BookDao bookDao) {
this.bookDao = bookDao;
}
}
DAO:
public interface BookDao extends JpaRepository<Book, Long> {
}
Thanks for any help!
If I run your code and make JPA generate tables based on the entities it seems to work (at least, it does run).
However, your mappings appear to be odd to me, more specifically the #JoinTable annotation. The #JoinTable annotation is commonly used when you have a join table (eg. checkoutSession in your case), but you don't want to map it because it contains no useful information except the links between those two tables.
In that case, you use the #JoinTable annotation as following:
#ManyToMany
#JoinTable(
name = "checkoutsession", // Name of the join table
joinColumns = #JoinColumn(name = "book"), // The column name in checkoutsession that links to book
inverseJoinColumns = #JoinColumn(name = "user") // The column name in checkoutsession that links to user
)
private List<User> users;
So in this case, you can directly link the Book and User entity without having to create the CheckoutSession entity.
However, in your case your join table also contains two timestamps, if you need those in your application, then you don't have to use #JoinTable but simply use #JoinColumn to link them, for example:
#OneToMany(mappedBy = "book") // The field name in CheckoutSession that links to book
private List<CheckoutSession> checkOutSessions;
This is what you should have in your Book entity. Be aware that in this case we're talking about field names not about column names. You have to enter the name of the field in CheckoutSession that maps back to the Book entity.
For more information about the #JoinTable annotation I recommend you to read this answer: JPA "#JoinTable" annotation or this article.
I have a following Entities. Means that User can belong to many businesses and for each business this user can has separate permissions. So an existing user can be assigned to another business. The Business_User table looks like this:
USER_ID BUSINESS_ID AUTHORITY_NAME
6 1 ROLE_ANALYTICS
6 1 ROLE_SELF_ANALYTICS
7 1 ROLE_REVIEWS
8 1 ROLE_ANALYTICS
8 1 ROLE_SELF_ANALYTICS
8 1 ROLE_REVIEWS
6 2 ROLE_REVIEWS
6 2 ROLE_SELF_ANALYTICS
Question: I am querying Users for ONE business by trying to build list of user DTO objects, that DTO exposes List<Authority>, problem is that I can't figure how should I get these authorities for each user from the Business_User table. Been trying to do fancy stuff with lambdas but have no luck. I am using Spring Data for queries, maybe can solve it in the repository.
Thanks in advance.
EDIT: If I would go another route by adding new join table BUSINESS_USER_AUTHORITY, how would I have to describe it in UserBusiness class? I also would like the primary key to be over user_id and business_id. Note that name is PK in Authority table.
Something like this, but that does not create me join table at all.
Change UserBusiness class:
#ManyToMany(fetch = FetchType.EAGER)
#JoinTable(
name = "BUSINESS_USER_AUTHORITY",
joinColumns = {#JoinColumn(name = "business_user_id", referencedColumnName = "id")},
inverseJoinColumns = {#JoinColumn(name = "authority_name", referencedColumnName = "name")})
private Set<Authority> authorities = new HashSet<>();
User
#Entity
#Table(name = "USER")
public class User extends AbstractAuditingEntity implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#OneToMany(cascade = CascadeType.ALL)
#JoinColumns({
#JoinColumn(name = "user_id", referencedColumnName = "id")
})
private Set<BusinessUser> businessUsers = new HashSet<>();
}
BusinessUser
#Entity
#Table(name = "BUSINESS_USER")
#IdClass(BusinessUser.class)
public class BusinessUser implements Serializable {
#Id
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "user_id")
private User user;
#Id
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "business_id")
private Business business;
#Id
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "authority_name")
private Authority authority;
}
Business
#Entity
#Table(name = "BUSINESS")
public class Business implements Serializable {
#OneToMany(cascade = CascadeType.ALL)
#JoinColumns({
#JoinColumn(name = "business_id", referencedColumnName = "id")
})
private Set<BusinessUser> businessUsers = new HashSet<>();
}
Authority
#Entity
#Table(name = "AUTHORITY")
public class Authority implements Serializable {
#NotNull
#Size(min = 0, max = 50)
#Id
#Column(length = 50)
private String name;
}
I ended up writing a function like that, but if anyone has a solution how would the design look with another join table between BusinessUser <--> BusinessUserAuthority then I'd be glad to implement it.
private Function<Map.Entry<User, List<BusinessUser>>, UserManagementDTO> getPermissionForUser() {
return user -> {
UserManagementDTO dto = userManagementMapper.userToUserManagementDTO(user.getKey());
dto.setAuthorities(user.getValue().stream().map(BusinessUser::getAuthority).collect(Collectors.toSet()));
return dto;
};
}