Send via http element's parent's id with #OneToMany relationship - postgresql

I want to be able to send via http the entire ProjectUrl list exactly as it appears in my postgres DB, with columns "id", "url" and "project_id" (just the id, not the whole project); and at the same time, to be able to send the projects with their urls. So using #JsonIgnore on the "project" property or on the "List" can't do the trick for me... Of course if i don't use #JsonIgnore, recursion takes over. Thanks!
#Entity
public class ProjectUrl {
#Id
#GeneratedValue
private UUID id;
#NonNull
private String url;
#JsonIgnore
#ManyToOne(fetch = FetchType.LAZY)
private Projects project;
//getters and setters...
}
#Entity
public class Projects {
#Id
#GeneratedValue
private UUID id;
private String title;
private String description;
#OneToMany(mappedBy = "project", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private List<ProjectUrl> urls = new ArrayList<ProjectUrl>();
//getters and setters...
}

Related

Spring Data Jpa OneToMany save bidirectional

I have a problem with saving child entities.
Here is my example. My model classes look like this:
#Entity
public class ImportDocument {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String title;
private boolean imported;
#Transient
private Status status;
#Basic
private char statusValue;
#OneToMany(mappedBy = "importDocument" , cascade = {CascadeType.ALL})
private List<ImportDocumentItem> importDocumentItems;
}
#Entity
public class ImportDocumentItem {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
#JoinColumn(name = "import_document_id")
#JsonIgnore
private ImportDocument importDocument;
}
I have implemented JpaRepository interfaces for both domain classes.
I try to save with:
importDocumentRepository.save(importDocument);
When I save ImportDocument object, everything is inserted. But the problem is that, the import_document_item.import_document_id (which is foreign key of import_document_id) attribute is filled with null value, not with id of import_document that I expected. How can I fix this issue?
Thanks a lot.
You have to set entity relations on both side before saving. Here an example
ImportDocument importDocument = new ImportDocument();
//...
importDocument.setImportDocumentItems(items);
items.forEach(ImportDocumentItem::setImportDocument);
importDocumentRepository.save(importDocument);

duplicate results when sorting by collection property

Repost from here
Given entities and repository:
#Entity
public final class Partner {
#Id
private String id;
#OneToMany(mappedBy = "partner", fetch = FetchType.LAZY)
private List<Merchant> merchants;
...
}
#Entity
public final class Merchant {
#Id
private String id;
#Column
private String name;
#ManyToOne(fetch = FetchType.LAZY)
private Partner partner;
...
}
public interface PartnerRepository
extends JpaRepository<Partner, String>, QueryDslPredicateExecutor<Partner> {
}
If there is only one partner having two merchants in the DB then the following code incorrectly returns list with two instances of the same parnter.
partnerRepository.findAll(new Sort("merchants.name"));
This is caused internally by the DB join. By creating custom implementation that adds the distinct to the selection the result is correctly the single partner.
Wouldn't it be correct to do distinct selection per default?
Try
#OneToMany(mappedBy = "partner", fetch = FetchType.LAZY)
#OrderBy("name")
private List<Merchant> merchants;

JPA two Entities one Relationship: How do I obtain a Set of an entity that is linked through a relationship?

I have three tables each mapping to one of these entities. The 'assigned' table acts as the relationship between 'users' and 'roles' with a foreign key to each table. How would I map this on my entities so that I can get a Set of EntityRoles from the UserEntity? I can't quite figure out how to make this work. Is this even possible?
#Entity
#Table(name = "users")
public class UserEntity {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name="user_id")
private long id;
#Column(name="user_username")
private String username;
#Column(name="user_password")
private String password;
#Column(name="user_email")
private String email;
//I want to be able to get a set of RoleEntities
#OneToMany(fetch = FetchType.LAZY, mappedBy = "id")
private Set<RoleEntity> roles;
}
#Entity
#Table(name = "assigned")
public class AssignedEntity implements Serializable {
#Id
//#Column(name = "assigned_role")
#ManyToOne(targetEntity = RoleEntity.class, fetch = FetchType.LAZY)
#JoinColumn(name = "fk_role")
private long roleId;
#Id
//#Column(name = "assigned_user")
#ManyToOne(targetEntity = UserEntity.class, fetch = FetchType.LAZY)
#JoinColumn(name = "fk_user")
private long userId;
}
#Entity
#Table(name = "roles")
public class RoleEntity implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name="role_id")
#OneToOne(fetch = FetchType.LAZY, mappedBy="roleId")
private long id;
#Column(name="role_name")
private String name;
}
You are using an incorrect/inconvenient mapping. Always keep things as simply as possible.
#Entity
#Table(name = "users")
public class User {
#Id
#GeneratedValue
private Long id;
#ManyToMany(fetch = FetchType.LAZY)
private List<Role> roles;
}
#Entity
#Table(name = "roles")
public class Role {
#Id
private Long id;
#Column
private String name;
}
A persistent provider will create a (valid) join table for you. You can specify the name of the join table using #JoinTable annotation. Also you will need to think about auto generation values of id for the Role entity: the roles table is something like a reference data table. So, probably, you will need to hardcode the id values.
To get user roles (in the persistent context):
user.getRoles()

JPA query method to find by elements in a List?

I have the following two entities (Contact and Participation, linked by a ManyToMany relation) :
#Entity
public class Contact {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
#Column(nullable=false)
private String firstName;
#Column(nullable=false)
private String lastName;
#ManyToOne
private Company company;
#ManyToMany(fetch=FetchType.EAGER)
private List<Participation> participations;
}
#Entity
public class Participation {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
#ManyToOne
private Company company;
private Status status;
}
I can't figure out how to get Contacts who have a specific Participation in their list. Should I look via Contacts with a specific JPA repository method (findBy...) ? Or would i have to look via the table which was created with both Contact and Participation IDs (ManyToMany) ?
Thanks!

How to map existing JPA entities to PicketLink

I am trying to migrate a Seam 2 app to CDI and use PicketLink for security. After all the reading and researching, it seems like all the examples are having one to one mapping between PicketLink model and the backend entity. e.g. Account to AccountEntity, Partition to PartitionEntity. Since I already have entities in place representing identity model, I am stuck on trying to map them to PicketLink. Here is what I have:
#MappedSuperClass
public class ModelEntityBase implement Serializable {
#Id #Generated
Long id;
Date creationDate;
}
#Entity
public Account extends ModelEntityBase {
String username;
String passwordHash;
#OneToOne(mappedBy = "account")
Person person;
}
#Entity
public Person extends ModelEntityBase {
String name;
String email;
#OneToOne
#JoinColumn(name = "account_id")
Account account;
}
Two entities (plus a super class) representing a single identity model in PicketLink, e.g. stereo type User.
Based on this why IdentityType id is String not Long, I tried to add a new Entity in:
#Entity
#IdentityManaged(BaseIdentityType.class);
public class IdentityTypeEntity implement Serializble {
#Id #Identifier
private String id;
#OneToOne(optional = false, mappedBy = "identityType")
#OwnerReference
private Account account;
#IdentityClass
private String typeName;
#ManyToOne #OwnerReference
private PartitionEntity partition;
}
I've tried a few different ways with the annotation and model classes. But when using IdentityManager.add(myUserModel), I just can't get it to populate all the entities. Is this even possible?
Got help from Pedro (PicketLink Dev). Post the answer here to help others.
This is the model class I ended up using.
#IdentityStereotype(USER)
public class User extends AbstractAttributedType implements Account {
#AttributeProperty
private Account accountEntity;
#AttributeProperty
#StereotypeProperty(IDENTITY_USER_NAME)
#Unique
private String username;
#AttributeProperty
private boolean enabled;
#AttributeProperty
private Date createdDate;
#AttributeProperty
private Date expiryDate;
#AttributeProperty
private Partition partition;
// getter and setter omitted
}
And created a new entity to map to this model:
public class IdentityTypeEntity implements Serializable {
#Id
#Identifier
private String id;
#OneToOne(optional = false, mappedBy = "identityType",
cascade = CascadeType.ALL, fetch = FetchType.EAGER)
#AttributeValue
// #NotNull
private HAccount accountEntity;
#IdentityClass
private String typeName;
#ManyToOne
#OwnerReference
private PartitionEntity partition;
#AttributeValue
private String username;
#AttributeValue
// #Transient
private boolean enabled;
#AttributeValue
private Date createdDate;
#AttributeValue
private Date expiryDate;
}
PL can map property with #AttributeProperty to entity property with #AttributeValue. But it can only map to one entity. Therefore there is no way to map, say User and its properties over to Account and Person. But you can have the entity (in my case accountEntity) in the model. I also have to duplicate a few fields in the new IdentityTypeEntity and my existing Account entity (username, eanbled, createdDate) because PL requires these. Use a #PrePersist and similar to sync them.