I have simple entity with field countUsing which specify count used in other table. It is subquery with annotation Formula.
And i would like in one case ignore execute query in formula but others subquery must invoke.
My entity:
#Entity
#Table(name = "roles")
public class Role {
#Id
#GeneratedValue(generator = "roles_id_seq", strategy = GenerationType.SEQUENCE)
#SequenceGenerator(name = "roles_id_seq", sequenceName = "roles_id_seq", allocationSize = 1)
#Column(name = "id")
private Long id;
#Column(name = "\"NAME\"")
private String name;
#Convert(converter = LocalDateTimeAttributeConverter.class)
private LocalDateTime insertDate;
#Convert(converter = LocalDateTimeAttributeConverter.class)
private LocalDateTime updateDate;
#Formula("(SELECT COUNT(*) FROM user_roles us WHERE us.id_role = id)")
private Integer countUsing;
}
How can i achive the target, i think about flag in any annotation for field countUsing.
Annotation Formula has got only value property.
I understand that you want use FetchType.LAZY on this attribute.
Therefore, you can`t use LAZY directly in a #Formula attribute in your class.
The solution for this is create an wrapper Class, with a oneToOne relationship to your class that`s contain your formula attribute, like this:
#Entity
#Table(name = "roles")
public class Role{
... /*other attributes*/
#OneToOne(fetch = FetchType.LAZY, mappedBy = "role")
private RoleCounting roleCouting;
}
#Entity
#Table(name = "roles")
public class RoleCounting{
#Id
#Column(name="id", insertable = false, updatable = false)
private Long id;
#OneToOne(fetch = FetchType.LAZY)
#MapsId
#JoinColumn(name = "id", insertable = false, updatable = false)
private Role role;
#Formula("(SELECT COUNT(*) FROM user_roles us WHERE us.id_role = id)")
private Integer countUsing;
}
That way, the subquery will only be executed when you invoke:
role.getRoleCounting().getCountUsing();
Related
I would like to ignore #OnetoMany field in my entity. fetch data need to get actual fields but don't want to fire query to dependent table. But deleting data from parent table needs deletion from dependent table
I have tried #Transient that ignores but the delete is also being ignored. Is there any other option to tell JPA not to fetch data from childs table when i call the parent entity?
#Entity
Table(name = "User")
public class UserEntity implements Serializable {
#Id
#Column(name = "id")
private int id;
#Column(name = "SERIAL", unique = true, nullable = false)
private String serial;
#OneToMany(mappedBy = "serialBySerialId", cascade = CascadeType.ALL)
private Set<UserActionEntity> userActionsById;
}
#Table(name = "user_action")
public class UserActionEntity implements Serializable {
#Id
#Column(name = "id")
private int id;
#Column(name = "action")
private String action;
#ManyToOne
#JoinColumn(name = "USER_ID", referencedColumnName = "ID", nullable = false)
private UserEntity userByUserId;
If you don't want to fire query to dependent table, you can use (fetch = FetchType.LAZY) on UserActionEntity property.
#OneToMany(mappedBy = "serialBySerialId", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
private Set<UserActionEntity> userActionsById;
I have Spring Data Entity:
#Entity
#Table(name = "price_alert")
#Data
public class PriceAlert {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "customer_id")
private Long customerId;
}
So, for insert/update this entity perfectly fit for me: no need to load entity by id (here: for save PriceAlert it would be needed to load Customer).
But for some selects I also want to retrieve Customer. Currently I solve this problem by having 2 entities with 2 different corresponding repositories. In first entity all fields are plain Long values. In second I use Mapped value (like bellow).
#Entity
#Table(name = "price_alert")
#Data
public class PriceAlertExtended {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#ManyToOne(optional = false)
#JoinColumn(name = "customer_id", referencedColumnName = "id")
private Customer customer;
}
With both #Column and #JoinColumn in entity on create I get SQLException: Field 'customer_id' doesn't have a default value
So my question is about: is there any better approach to this problem?
For your particular use case. I would suggest you to look at the following snippet
#Entity
#Table(name = "price_alert")
#Data
public class PriceAlertExtended {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#ManyToOne(optional = false, fetch = FetchType.LAZY)
#JoinColumn(name = "customer_id", referencedColumnName = "id")
private Customer customer;
#Column(name = "customer_id", insertable = false, updatable = false, nullable = false)
private Long customerId;
}
Here, I have used fetch = FetchType.LAZY in #ManyToOne, this will save a JOIN on Customer Table until to access it by person.getCustomer().
And, I have created an extra field to access customerId to just get the customer_id. Make sure to mention nullable = false, insertable = false and updatable = false
Ive added 2 hibernate model objects
First table
#Entity
#Table(name = "ACTIVITIES")
public class ActivityMO extends ModelBase {
#Column(name = "CA_ID", nullable = false, insertable = true,updatable = true, length = 22, precision = 0)
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator = "G1")
#SequenceGenerator(name = "G1", sequenceName = "CSM_ACTIVITIES_SEQ")
private Long id;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "activityId", cascade = {CascadeType.ALL})
#Fetch(FetchMode.JOIN)
List<ActivitiesProductsMO> relatedProducts;
...getters / setters
}
The other table is
#Entity
#Table(name = "ACTIVITIES_PRODUCTS")
public class ActivitiesProductsMO {
#Column(name = "CAP_ID")
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator = "G1")
#SequenceGenerator(name = "G1", sequenceName = "ACTIVITIES_PRODUCTS_SEQ")
private Long id;
#Column(name = "CAP_ACTIVITY_ID")
private Long activityId;
#Column(name = "CAP_PRODUCT_ID")
private Long productId;
...getters/setters
}
The point is to populate each db record for ActivitiesProductsMO.activityId with ActivityMO.id value
I.e.
If I create an activity record with id = 555
I'll get another activity_product record with activityId of 555
How can i get this to work?
Thank you!
Instead of manually trying to map the entitiy relations with long values you should use a bidirectional OneToMany relationship from ActivityMO to ActivitiesProductsMO
change ActivitiesProductsMO to:
#Entity
#Table(name = "ACTIVITIES_PRODUCTS")
public class ActivitiesProductsMO {
// cut unimportant code ...
#ManyToOne
#JoinColumn(name = "CAP_ACTIVITY_ID")
private ActivityMO activityId;
// cut unimportant code ...
}
If you then were to persist an ActivityMO that already has ActivitiesProductsMO entries in its relatedProducts List, the Cascade type should actually take care and create those products while filling out the CAP_ACTIVITY_ID database field with the right value.
Another Possible Solution:
Use a Unidirectional OneToMany:
#Entity
#Table(name = "ACTIVITIES")
public class ActivityMO extends ModelBase {
#OneToMany(fetch = FetchType.LAZY, cascade = {CascadeType.ALL})
#Fetch(FetchMode.JOIN)
#JoinColumn(name = "CAP_ACTIVITY_ID")
List<ActivitiesProductsMO> relatedProducts;
}
And remove the
private Long activityId;
from your ActivitiesProductsMO class.
This should both lead to identical database structure. But in the second case you would no longer have the "backlink" inside java from ActivitiesProductsMO to ActivityMO
When JPA tries to select AdmUser entity I have sql error:
ERROR: column locations1_.name does not exist.
Is there anything wrong with my entities? My AdmUser entity:
#Entity
#Table(name = "ADM_USERS")
#SequenceGenerator(name = "ADM_USER_SEQ", sequenceName = "ADM_USER_SEQ", allocationSize = 1)
public class AdmUser implements EntityInt, Serializable {
private static final long serialVersionUID = 786L;
#Id
#Column(nullable = false)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "ADM_USER_SEQ")
private Long id;
(...)
#ManyToMany(cascade = CascadeType.MERGE, fetch = FetchType.EAGER)
#JoinTable(name = "loc_locations_adm_users", joinColumns = #JoinColumn(name = "id_user", referencedColumnName="id"),
inverseJoinColumns = #JoinColumn(name = "id_location"))
#OrderBy("name")
private Set<LocLocation> locations;
(...)
}
My LocLocation Entity:
#Entity
#Table(name = "loc_locations", schema = "public")
#SequenceGenerator(name = "LOC_LOCATIONS_SEQ", sequenceName = "LOC_LOCATIONS_SEQ", allocationSize = 1)
public class LocLocation implements EntityInt, java.io.Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name = "id", unique = true, nullable = false)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "LOC_LOCATIONS_SEQ")
private Long id;
#Column(nullable = false, unique = true, length = 200)
private String name;
(...)
#ManyToMany(cascade = CascadeType.REFRESH, fetch = FetchType.LAZY, mappedBy="locations")
private List<AdmUser> users;
}
And now - when JPA tries to select AdmUser entity I have sql error. The query generated by JPA looks that:
select
admuser0_.id as id1_2_0_,
admuser0_.actived as actived2_2_0_,
admuser0_.admin as admin3_2_0_,
admuser0_.allow_ip as allow_ip4_2_0_,
admuser0_.created as created5_2_0_,
admuser0_.deleted as deleted6_2_0_,
admuser0_.id_domain as id_doma16_2_0_,
admuser0_.email as email7_2_0_,
admuser0_.language as language8_2_0_,
admuser0_.login as login9_2_0_,
admuser0_.name as name10_2_0_,
admuser0_.passwd as passwd11_2_0_,
admuser0_.phone as phone12_2_0_,
admuser0_.picture as picture13_2_0_,
admuser0_.surname as surname14_2_0_,
admuser0_.theme as theme15_2_0_,
locations1_.id_user as id_user1_2_1_,
loclocatio2_.id as id_locat2_6_1_,
loclocatio2_.id as id1_17_2_,
loclocatio2_.description as descript2_17_2_,
loclocatio2_.name as name3_17_2_
from
public.ADM_USERS admuser0_
left outer join
public.loc_locations_adm_users locations1_
on admuser0_.id=locations1_.id_user
left outer join
public.loc_locations loclocatio2_
on locations1_.id_location=loclocatio2_.id
where
admuser0_.id=1
order by
locations1_.name
The order by points to locations1_.name, but should be loclocatio2_.name. Have I anything wrong with my entities?
You have a Set on one side for that field. Consequently there is no "ordering" (other than what hashCode() gves). Use a List if you want ordering (this is Java, nothing to do with JPA really).
You also seem to be missing a "mappedBy" on the non-owner side of that M-N.
The #OrderBy works fine with ManyToMany. Also with the structure I provided in my question. The problem was my query and JPA didn't managed with it. Sorry.
I have two tables :
A(bigint id, ...)
B(bigint id, varchar name, bigint id_A)
and now I want get all rows from A which exists in B (and those rows in B have name eg Andy)
Plase help me create dynamic query
class A
#Entity
#Table(name = "A", schema = "mySchema")
#Cache(usage = CacheConcurrencyStrategy.TRANSACTIONAL)
public class A{
#Id
private Long id;
}
class B
#Entity
#Table(name = "B",
schema = "mySchema",
uniqueConstraints = { #UniqueConstraint(columnNames = {
"some_id", "id_A" }) })
public class B{
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator = "Seq")
#SequenceGenerator(name = "Seq", sequenceName = "mySchema.mySeq")
private Long id;
#OneToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "id_A", nullable = false)
private A a;
#Column(name = "id_A", updatable = false, insertable = false)
private Long IdA;
}
There are several weird parts. e.g. this:
#OneToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "id_A", nullable = false)
private A a;
#Column(name = "id_A", updatable = false, insertable = false)
private Long IdA;
With the #JoinColumn annotation you are telling the JPA provider that it should use the specified column for internal mapping, but with the IdA field, you are trying to manage the column yourself. Which is it going to be?