Jpa one to many using join table - mysql

Question

I have a room entity, a rule entity and an amenities entity. What i want to do is have the rule and the amenities entity filled manually beforehand and when i insert a room, i want depending on what rules and amenities the user chose to map the two in two join tables, room_rules and room_amenities.
How am i supposed to achieve this? When i persist a new Room Entity, should it already contain the rules and the amenities? Is it going to work if the collection of those are not mapped as cascade.persist?
Or should i 1st persist the room without them and then map them to the room?
What should i do?
UPDATE
My RoomEntity:
public class RoomEntity {
#Id
#GeneratedValue(strategy= GenerationType.SEQUENCE)
#Column(name = "id", nullable =false, unique = true)
private Integer id;
#Basic
#Column(name = "title", nullable = false, length = 45)
private String title;
#Basic
#Column(name = "description", nullable = false, length = 300)
private String description;
#Basic
#Column(name = "square_meters", nullable = false)
private Integer square_meters;
#Basic
#Column(name = "overnight_price", nullable = false)
private double overnight_price;
#Basic
#Column(name = "exta_person_price", nullable = false)
private double exta_person_price;
#Basic
#Column(name = "max_people", nullable = false)
private Integer max_people;
#Basic
#Column(name = "min_overnights", nullable = false)
private Integer min_overnights;
#Basic
#Column(name = "beds", nullable = false)
private Integer beds;
#Basic
#Column(name = "bathrooms", nullable = false)
private Integer bathrooms;
#Basic
#Column(name = "bedrooms", nullable = false)
private Integer bedrooms;
#Basic
#Column(name = "transport", length = 300)
private String transport;
#Basic
#Column(name = "neightborhood", length = 300)
private String neightborhood;
#Basic
#Column(name = "house_rules", length = 200)
private String house_rules;
#ManyToOne(cascade = CascadeType.MERGE)
#JoinColumn(name = "room_host", referencedColumnName = "username", /*nullable = false,*/ insertable = false, updatable = false)
private HostEntity hostEntity;
public HostEntity getHostEntity() {
return hostEntity;
}
public void setHostEntity(HostEntity hostEntity) {
this.hostEntity = hostEntity;
}
#OneToOne
#JoinColumn(name = "room_type_id", referencedColumnName = "id", /*nullable = false,*/ insertable = false, updatable = false)
private TypeEntity typeEntity;
public TypeEntity getTypeEntity() {
return typeEntity;
}
public void setTypeEntity(TypeEntity typeEntity) {
this.typeEntity = typeEntity;
}
#OneToOne(cascade={CascadeType.ALL})
#JoinColumn(name = "room_location", referencedColumnName = "id"/*, nullable = false, insertable = false, updatable = false*/)
private LocationEntity locationEntity;
public LocationEntity getLocationEntity() {
return locationEntity;
}
public void setLocationEntity(LocationEntity locationEntity) {
this.locationEntity = locationEntity;
}
#OneToMany(cascade = {CascadeType.ALL})
#JoinTable(
/*name = "room_pictures",*/
joinColumns = {#JoinColumn(name = "room_id", referencedColumnName = "id")},
inverseJoinColumns = {#JoinColumn (name ="picture_id", referencedColumnName = "id", unique = true)}
)
private Collection<PictureEntity> pictureEntities = new ArrayList<>();
public Collection<PictureEntity> getPictureEntities() {
return pictureEntities;
}
public void setPictureEntities(Collection<PictureEntity> pictureEntities) {
this.pictureEntities = pictureEntities;
}
#OneToMany
#JoinTable(
/*name = "room_amenities",*/
joinColumns = {#JoinColumn(name = "room_id", referencedColumnName = "id")},
inverseJoinColumns = {#JoinColumn (name ="amenity_id", referencedColumnName = "id")}
)
private Collection<AmenitiesEntity> amenitiesEntities = new ArrayList<>();
public Collection<AmenitiesEntity> getAmenitiesEntities() {
return amenitiesEntities;
}
public void setAmenitiesEntities(Collection<AmenitiesEntity> amenitiesEntities) {
this.amenitiesEntities = amenitiesEntities;
}
#OneToMany
#JoinTable(
/*name = "room_amenities",*/
joinColumns = {#JoinColumn(name = "room_id", referencedColumnName = "id")},
inverseJoinColumns = {#JoinColumn (name ="rule_id", referencedColumnName = "id")}
)
private Collection<RuleEntity> ruleEntities = new ArrayList<>();
public Collection<RuleEntity> getRuleEntities() {
return ruleEntities;
}
public void setRuleEntities(Collection<RuleEntity> ruleEntities) {
this.ruleEntities = ruleEntities;
}
public Collection<Picture> toPicturesModel(){
Collection<Picture> pictures = new ArrayList<>();
for(PictureEntity o : this.pictureEntities){
pictures.add(o.toModel());
}
return pictures;
}
public Collection<Amenities> toAmenitiesModel(){
Collection<Amenities> amenities = new ArrayList<>();
for(AmenitiesEntity o : this.amenitiesEntities){
amenities.add(o.toModel());
}
return amenities;
}
public Collection<Rule> toRulesModel(){
Collection<Rule> rules = new ArrayList<>();
for(RuleEntity o : this.ruleEntities){
rules.add(o.toModel());
}
return rules;
}
public Room toModel(Integer depth){
System.out.println("RoomEntity:::toModel()");
return new Room(
this.hostEntity == null? null : this.hostEntity.toModel(depth),
this.getTypeEntity() == null? null : this.typeEntity.toModel(),
this.getLocationEntity()== null? null : this.locationEntity.toModel(),
this.getPictureEntities() == null ? null : this.toPicturesModel(),
this.getAmenitiesEntities() == null? null : this.toAmenitiesModel(),
this.getRuleEntities() == null? null : this.toRulesModel(),
this.title, this.description, this.square_meters,
this.overnight_price, this.exta_person_price,
this.max_people, this.min_overnights, this.beds, this.bathrooms,
this.bedrooms, this.transport, this.neightborhood, this.house_rules);
}
}
My HostEntity inherits from RenterEntity the primary key username:
public class HostEntity extends RenterEntity {
#Basic
#Column(name = "about", length = 200)
private String about;
#Basic
#Column(name = "confirmed", nullable = false)
private boolean confirmed;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "hostEntity")
private Collection<RoomEntity> roomEntities;
public Collection<RoomEntity> getRoomEntities() {
return roomEntities;
}
public void setRoomEntities(Collection<RoomEntity> roomEntities) {
this.roomEntities = roomEntities;
}
My LocationEntity:
public class LocationEntity{
#Id
#GeneratedValue(strategy=GenerationType.SEQUENCE)
#Column(name = "id", nullable =false, unique = true)
private Integer id;
#Basic
#Column(name = "latitude", nullable = false, precision = 0)
private double latitude;
#Basic
#Column(name = "longitude", nullable = false, precision = 0)
private double longitude;
#Basic
#Column(name = "street_number", length = STREET_MAX)
private String street_number;
#Basic
#Column(name= "route", length = ROUTE_MAX)
private String route;
#Basic
#Column(name = "locality", length = LOCALITY_MAX)
private String locality;
#Basic
#Column(name = "postal_code", length = POSTAL_CODE_MAX)
private String postal_code;
#Basic
#Column(name = "country", length = COUNTRY_MAX)
private String country;
#Basic
#Column(name = "administrative_area_level_5", length = ADMINISTRATIVE_AREA_LEVEL_MAX)
private String administrative_area_level_5;
#Basic
#Column(name = "administrative_area_level_4", length = ADMINISTRATIVE_AREA_LEVEL_MAX)
private String administrative_area_level_4;
#Basic
#Column(name = "administrative_area_level_3", length = ADMINISTRATIVE_AREA_LEVEL_MAX)
private String administrative_area_level_3;
#Basic
#Column(name = "administrative_area_level_2", length = ADMINISTRATIVE_AREA_LEVEL_MAX)
private String administrative_area_level_2;
#Basic
#Column(name = "administrative_area_level_1", length = ADMINISTRATIVE_AREA_LEVEL_MAX)
private String administrative_area_level_1;
#Basic
#Column(name = "formatted_address", length = FORMATTED_ADRESS_MAX, nullable = false, unique = true)
private String formatted_address;
}
My TypeEntity:
public class TypeEntity {
#Id
#Column(name = "id", nullable = false, unique = true)
private Integer id;
#Basic
#Column(name = "type_name", nullable = false, length = 45)
private String type;
#OneToOne(mappedBy = "typeEntity")
private RoomEntity roomEntity;
}
My RuleEntity:
public class RuleEntity {
#Id
#Column(name = "id", nullable =false, unique = true)
//#GeneratedValue(strategy= GenerationType.SEQUENCE)
private Integer id;
#Basic
#Column(name = "rule", nullable =false , unique = true, length = 50)
private String rule;
}
My PictureEntity:
public class PictureEntity {
#Id
#Column(name = "id", nullable =false, unique = true)
#GeneratedValue(strategy= GenerationType.SEQUENCE)
private Integer picture_id;
#Basic
#Column(name = "thumbnail_url", nullable =false, length = 100)
private String thumbnail_url;
#Basic
#Column(name = "medium_url", nullable =false, length = 100)
private String medium_url;
#Basic
#Column(name = "picture_url", nullable =false, length = 100)
private String picture_url;
#Basic
#Column(name = "xl_picture_url", nullable =false, length = 100)
private String xl_picture_url;
}
My AmenitiesEntity:
public class AmenitiesEntity {
#Id
#Column(name = "id", nullable =false, unique = true)
//#GeneratedValue(strategy= GenerationType.SEQUENCE)
private Integer id;
#Basic
#Column(name = "name", nullable = false, unique = true, length = 50)
private String amenity;
}
My code that creates a room is this:
public Room addRoom(RoomInput room) {
dao.setParam("username", room.getOwner());
List<HostEntity> owner = dao.getTuples("users.findByUsername");
RoomEntity newRoom = new RoomEntity(room.getTitle(), room.getDescription(), room.getSquare_meters(), room.getOvernight_price(),
room.getExta_person_price(), room.getMax_people(), room.getMin_overnights(), room.getBeds(), room.getBathrooms(),
room.getBedrooms(), room.getTransport(), room.getNeightborhood(), room.getHouse_rules());
newRoom.setLocationEntity(room.getLocation().toEntity());
for(Picture o :room.getPictures()){
newRoom.getPictureEntities().add(o.toEntity());
}
RoomEntity entity = dao.insertTuple(newRoom);
entity.setHostEntity(owner.get(0));
for(Amenities o : room.getAmenities()){
entity.getAmenitiesEntities().add(o.toEntity());
}
for(Rule o : room.getRules()){
entity.getRuleEntities().add(o.toEntity());
}
entity.setTypeEntity(room.getType().toEntity());
entity = dao.updateTuple(entity);
System.out.println(entity.toString());
return (entity == null) ? null : entity.toModel(0);
}
What happens now is that, even though my 3 join tables,
room_pictures, room_rules, room_amenities get updated correctly,
the room i put in the database has the foreign key of the host(username)
and the type(id) null.
Is there a better way in doing all this? Right now i 1st persist the new room,
and cascade persist the pictures and the location and then i merge the room with the new values of host, amenities and rules updated.

Answer 1

UPDATE
I fixed the problem. Now i do one insert for the entities i want to persist with the room, aka location and pictures and one merge to connect the detatched entities amenities/rules in the join tables and host/type foreign keys in the room table. The problem with host and type was that i had in the #JoinColumn updateable and instertable to be false which was wrong. After i deleted those statements, it worked! My code in the end to persist/merge the detatched and new entities is this:
public Room addRoom(RoomInput room) {
dao.setParam("username", room.getOwner());
HostEntity host = null;
List<HostEntity> owner = dao.getTuples("users.findByUsername");
RoomEntity newRoom = new RoomEntity(room.getTitle(), room.getDescription(), room.getSquare_meters(), room.getOvernight_price(),
room.getExta_person_price(), room.getMax_people(), room.getMin_overnights(), room.getBeds(), room.getBathrooms(),
room.getBedrooms(), room.getTransport(), room.getNeightborhood(), room.getHouse_rules());
System.out.println(owner.get(0).toString());
newRoom.setLocationEntity(room.getLocation().toEntity());
for(Picture o :room.getPictures()){
newRoom.getPictureEntities().add(o.toEntity());
}
RoomEntity entity = dao.insertTuple(newRoom);
for(Amenities o : room.getAmenities()){
entity.getAmenitiesEntities().add(o.toEntity());
}
for(Rule o : room.getRules()){
entity.getRuleEntities().add(o.toEntity());
}
entity.setHostEntity(owner.get(0));
entity.setTypeEntity(room.getType().toEntity());
dao.updateTuple(entity);
System.out.println(entity.toString());
return (entity == null) ? null : entity.toModel(0);
}