I have an entity who own many object
#Entity
public class Lodger implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long lodgerId;
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "lodger")
private List<IdentityCard> identityCardList;
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "lodger")
private List<Phone> phoneList;
...
}
#Entity
public class IdentityCard {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long identityCardId;
private String identyCardValue;
#OneToOne
#JoinColumn(name = "identity_card_type_id") //without -> identity_card_type_identityCardTypeId
private IdentityCardType identityCardType;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "lodger_id")
private Lodger lodger;
}
When i save my lodger, all my object is saved (identiyCard, phone), but their field lodger_id is null.
I was thinking it was supposed to be done automatically when we use cascadeType.all.
The owner side of the bi-directioinal associations are in IdentityCard and Phone entities, this is the same as saying that the mappedBy is in Lodger's associations.
So for the persistence of the links you must set the lodger attribute in IdentityCard and Phone entities. Isn't necessary to add this entities to the Lodger's collections but it is fine because you want to save this entities along with Lodger using cascade option.
Related
I have two table user(id,name) and user_mails(id,email,user_id) user to user_mails have one to many relation.
I have created following entity in spring boot
User
#Entity
#Table(name = "user")
public class User {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id")
private int id;
#Column(name = "name", nullable = false)
private String name;
#OneToMany(mappedBy = "user", cascade = CascadeType.ALL)
private Set<UserMail> userMails =new HashSet<UserMail>(0);
//Getter setter and constructor
}
UserMail
#Entity
#Table(name = "user_mails")
public class UserMail {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
#Column(name = "email", nullable = false)
private String name;
#ManyToOne(fetch = FetchType.LAZY, optional = false)
#JoinColumn(name = "user_id")
private User user;
It is showing following output on calling controller
[{"id":1,"name":"Ram","userMails":[{"id":2,"name":"ram#b.com","user":{"id":1,"name":"Ram","userMails":[{"id":2,"name":"ram#b.com","user":{"id":1,"name":"Ram","userMails":[{"id":2,"name":"ram#b.com","user":{"id":1,"name":"Ram","userMails":[{"id":2,"name":"ram#b.com","user":{"id":1,"name":"Ram","userMails":[{"id":2,"name":"ram#b.com","user":{"id":1,"name":"Ram","userMails":[{"id":2,"name":"ram#b.com","user":{"id":1,"name":"Ram","userMails":
and more
I want to access all users with all mail ids also want to acces mail id with user details
What changes should I do to get proper result
I'm writing an app to operate a collection of hardware that is supposed to be setup and shutdown repeatedly in different locations.
I want to track those installations so I've created separate entities for a physical object itself and the installation.
Station object needs to keep track of up to one (null while not installed) active installation information (so #OneToOne) but also all the previous installations (so #OneToMany)
#Entity
#Table(name = "station")
class Station{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#OneToOne(mappedBy = "stationInstallation", cascade = CascadeType.DETACH,
CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH)
#JoinColumn(name = "station_installation_id", nullable = true)
private StationInstallation activeStationInstallation;
...
#OneToMany(fetch = FetchType.Lazy, mappedBy = "station_id", cascade =
{CascadeType.DETACH, CascadeType.PERSIST,
CascadeType.MERGE, CascadeType.REFRESH })
private List<stationInstallation> stationInstallations;
...
}
The other entity will have the station id, location and date of the setup as well as the shutdownDateTime being null.
#Entity
#Table(name = "stationInstallation")
class StationInstallation{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#OneToOne(mappedBy ="stationInstallation", cascade - CascadeType.ALL)
private Station station;
#Column(name = "location")
private String location;
#Column(name = "setupDateTime")
private LocalDateTime setupDateTime;
#Column(name = "shutdownDateTime")
private LocalDateTime shutdownDateTime
}
Finally the shutdown method is supposed to unattach the entity from the Station entity by setting activeStationInstallation to null and setting shutdownDateTime to LocalDateTime.NOW.
...
stationInstallation.getStation().setActiveStationInstallation(null);
stationInstallation.setShotdownDateTime(LocalDateTime.NOW);
...
But that will obviously result in a growing number of StationInstallation "finished" objects, which would seem to require #ManyToOne relation with the Station all the while I want to keep #OneToOne relation with the activeStationInstallation.
What do?
I figured I could just make another entity calling it FinishedStationInstallation, remove shutdownDateTime from StationInstallation, make both immutable and instead of adding shutdownDateTime with a setter add it in the constructor while deleting the active version. And immutablity is an asset, ut at the same time I'd have to add several new tables to the db and keep track of and query two entities instead of one.
EDIT: I guess I could get rid of List stationInstallations from the 1st entity, since I don't really need to keep the track of it beyond db queries, but I added it for the clarity of the question.
I would model it this way:
#Entity
#Table(name = "station")
class Station{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#OneToOne(cascade = CascadeType.DETACH,
CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH)
#JoinColumn(name = "station_installation_id", nullable = true)
private StationInstallation activeStationInstallation;
...
#OneToMany(fetch = FetchType.Lazy, mappedBy = "station", cascade =
{CascadeType.DETACH, CascadeType.PERSIST,
CascadeType.MERGE, CascadeType.REFRESH })
private List<stationInstallation> stationInstallations;
...
}
#Entity
#Table(name = "stationInstallation")
class StationInstallation{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#ManyToOne(mappedBy ="stationInstallation", cascade = CascadeType.ALL)
private Station station;
#Column(name = "location")
private String location;
#Column(name = "setupDateTime")
private LocalDateTime setupDateTime;
#Column(name = "shutdownDateTime")
private LocalDateTime shutdownDateTime
}
The one-to-one relation from Station to installation has a FK => so no mapped by
The one-to-many relation from Station to installation is mapped by the station association on installation, which obviously has to be a many-to-one association, since the other side is a one-to-many
I have an app with Angular front end and Spring backend. The two classes in question here are (backend):
#Setter
#Getter
#AllArgsConstructor
#NoArgsConstructor
#Entity
#Table(name = "tournament_games")
#JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
public class TournamentGame {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#ManyToOne(fetch = FetchType.EAGER, optional = false)
#JoinColumn(name = "code", foreignKey = #ForeignKey(name = "code_fk"))
private TournamentCode code;
#ManyToOne(fetch = FetchType.EAGER, optional = false)
#JoinColumn(name = "type", foreignKey = #ForeignKey(name = "game_type_fk"))
private GameType type;
#Column(name = "home_score")
private int home_score;
#Column(name = "away_score")
private int away_score;
#ManyToOne(fetch = FetchType.EAGER, optional = false)
#JoinColumn(name = "result_type", foreignKey = #ForeignKey(name = "result_type_fk"))
private ResultType result_type;
#Column(name = "status")
private boolean status;
#Column(name = "round")
private int round;
#Column(name = "locked")
private boolean locked;
#OneToMany(mappedBy = "game", fetch = FetchType.EAGER)
private List<TournamentGamesPlayers> players = new ArrayList<>();
}
and
#Setter
#Getter
#AllArgsConstructor
#NoArgsConstructor
#Entity
#Table(name = "tournament_games_players")
#JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "game")
public class TournamentGamesPlayers implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#ManyToOne
#JoinColumn(name = "tournament_game_id")
private TournamentGame game;
#Id
#ManyToOne
#JoinColumn(name = "playerid")
private Player player;
#Column(name = "home")
private boolean home;
}
I need help figuring out how to persist the List<TournamentGamesPlayers> when I save and/or update a TournamentGame object. I generate 45 games. The first 30 games have known players, and so I set them before saving. The last 15 do not have entries for the TournamentGamesPlayers join table, because I need to add them later.
I am able to get some results with CascadeType.ALL on the #OneToMany side when I initially generate the games, but it fails when I try to update a game with a seemingly infinite recursion/stack overflow.
If I omit any cascade type, the games side get generated, but the join table #ManyToOne side does not get entered.
I ended up just putting the players back into the game table to make my life easier.
try putting CascadeType.MERGE, CascadeType.ALL "delete parent and orphans" (JPA CascadeType.ALL does not delete orphans).
Also, defining the relationship as EAGER and not ignoring the JSON property can have problems. I would add #JsonIgnore to one of the parts of the relationship
I'm getting this error when I try to delete a pet. This pet, has visits (child) but I have defined CASCADE.ALL in pet entity. Any idea ?
ERROR:
Cannot delete or update a parent row: a foreign key constraint fails (web_customer_tracker.visits, CONSTRAINT visits_ibfk_1 FOREIGN KEY (pet_id) REFERENCES pets (pet_id))
#Entity
#Table(name = "pets")
public class Pet {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "pet_id")
private int pet_id;
.....
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "visit_id")
private Set<Visit> visits;
Visit class:
#Entity
#Table(name = "visits")
public class Visit {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "visit_id")
private int visit_id;
#ManyToOne
#JoinColumn(name = "pet_id")
private Pet pet;
....
you are using mappedBy in a wrong way
the mappedBy refers to the object name in the opposite side
like this
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "pet")
private Set<Visit> visits;
or if you want to map it by the JoinColum try this
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
#JoinColumn(name = "pet_id")
private Set<Visit> visits;
I am having an issue in setting up a one to many relationship in my annotated object.
I have the following:
#MappedSuperclass
public abstract class MappedModel
{
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
#Column(name="id",nullable=false,unique=true)
private Long mId;
then this
#Entity
#Table(name="customer")
public class Customer extends MappedModel implements Serializable
{
/**
*
*/
private static final long serialVersionUID = -2543425088717298236L;
/** The collection of stores. */
#OneToMany(mappedBy = "customer", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private Collection<Store> stores;
and this
#Entity
#Table(name="store")
public class Store extends MappedModel implements Serializable
{
/**
*
*/
private static final long serialVersionUID = -9017650847571487336L;
/** many stores have a single customer **/
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn (name="customer_id",referencedColumnName="id",nullable=false,unique=true)
private Customer mCustomer;
what am i doing incorrect here
The mappedBy attribute is referencing customer while the property is mCustomer, hence the error message. So either change your mapping into:
/** The collection of stores. */
#OneToMany(mappedBy = "mCustomer", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private Collection<Store> stores;
Or change the entity property into customer (which is what I would do).
The mappedBy reference indicates "Go look over on the bean property named 'customer' on the thing I have a collection of to find the configuration."
I know the answer by #Pascal Thivent has solved the issue. I would like to add a bit more to his answer to others who might be surfing this thread.
If you are like me in the initial days of learning and wrapping your head around the concept of using the #OneToMany annotation with the 'mappedBy' property, it also means that the other side holding the #ManyToOne annotation with the #JoinColumn is the 'owner' of this bi-directional relationship.
Also, mappedBy takes in the instance name (mCustomer in this example) of the Class variable as an input and not the Class-Type (ex:Customer) or the entity name(Ex:customer).
BONUS :
Also, look into the orphanRemoval property of #OneToMany annotation. If it is set to true, then if a parent is deleted in a bi-directional relationship, Hibernate automatically deletes it's children.
public class User implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name = "USER_ID")
Long userId;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "sender", cascade = CascadeType.ALL)
List<Notification> sender;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "receiver", cascade = CascadeType.ALL)
List<Notification> receiver;
}
public class Notification implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name = "NOTIFICATION_ID")
Long notificationId;
#Column(name = "TEXT")
String text;
#Column(name = "ALERT_STATUS")
#Enumerated(EnumType.STRING)
AlertStatus alertStatus = AlertStatus.NEW;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "SENDER_ID")
#JsonIgnore
User sender;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "RECEIVER_ID")
#JsonIgnore
User receiver;
}
What I understood from the answer. mappedy="sender" value should be the same in the notification model. I will give you an example..
User model:
#OneToMany(fetch = FetchType.LAZY, mappedBy = "**sender**", cascade = CascadeType.ALL)
List<Notification> sender;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "**receiver**", cascade = CascadeType.ALL)
List<Notification> receiver;
Notification model:
#OneToMany(fetch = FetchType.LAZY, mappedBy = "sender", cascade = CascadeType.ALL)
List<Notification> **sender**;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "receiver", cascade = CascadeType.ALL)
List<Notification> **receiver**;
I gave bold font to user model and notification field. User model mappedBy="sender " should be equal to notification List sender; and mappedBy="receiver" should be equal to notification List receiver; If not, you will get error.