I have two classes:
public class Account {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "accountId")
private Long id;
#OneToOne(optional = true)
#JoinColumn(name = "informationId")
private Information information;
}
public class Information {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "informationId")
private Long id;
#OneToOne(mappedBy = "information", cascade = CascadeType.ALL, optional = true)
private Account account;
}
When I make a call that retrieves an Account, I get this exception:
WARN o.h.e.loading.internal.LoadContexts - HHH000100: Fail-safe cleanup (collections) : org.hibernate.engine.loading.internal.CollectionLoadContext#2ecc21a
WARN o.h.e.l.i.CollectionLoadContext - HHH000160: On CollectionLoadContext#cleanup, localLoadingCollectionKeys contained [1] entries
WARN Unable to find Information with id 114; nested exception is javax.persistence.EntityNotFoundException: Unable to find Information with id 114
However, the database shows that there is an Information object with informationId 114, and an Account with a informationId foreign key of 114.
How come I am getting this exception?
EDIT
This is the call that causes the exception:
List<Following> following = followingService.findFollowingByUserId(userId);
In followingService, this is just a call to the dao. A Following object has a User object, and the User owns an Account. The following object populates just fine if I remove the Account mapping
Can you post complete code where this entity is being persisted and fetched?
This information is not sufficient to answer this query.
Could it be that you have a table with 1 entity and the other table with 0?
For me it seems like this:
Account
ID | Name | InformationID
-------------------------
1 | Acc | 114
-------------------------
Information
ID | Name | Account
-------------------
-------------------
Related
Post entity:
public class Post {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#OneToMany(mappedBy = "post")
private List<PostComment> postComments;
...
}
PostComment entity:
public class PostComment {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#ManyToOne
#JoinColumn(name = "post_id")
private Post post;
#OneToMany(mappedBy = "postComment")
private Set<PostCommentUpvote> postCommentUpvotes;
#OneToMany(mappedBy = "postComment")
private Set<PostCommentDownvote> postCommentDownvotes;
...
}
PostCommentUpvote entity (PostCommentUpvote and PostCommentDownvote have the exact same fields - these entities act like counters)
public class PostCommentUpvote {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#ManyToOne
#JoinColumn(name = "post_comment_id")
private PostComment postComment;
#ManyToOne
#JoinColumn(name = "user_id")
private User user;
...
}
All relations are bi-directional as you can see from the annotations.
The goal: When a user (authenticated) upvotes/downvotes a PostComment I want to do the following:
Check if user already upvoted/downvoted the PostComment.
For this I have Post id (even though this is not needed) and PostComment id and both are indexed.
There are three possible 'states' when User up/downvotes the comment:
User hasn't yet up/downvoted that comment, so it is either new upvote or new downvote
User has already upvoted and if he upvotes again, it will remove the upvote (same with downvote)
User has already upvoted and if he downvotes, upvote is removed and new downvote is added (and vice-versa)
What would be the most optimal way of doing this? Get the PostComment by its id and then loop through the List of PostCommentUpvote/PostCommentDownvote and check the User on every iteration? Or perform a tactical SQL request, which must be faster than looping in Java? If so, what would this SQL query look like? Or any other approach to make this performant. I am open to any suggestion.
Thanks
Assuming you have the post comment id and user id, the following JPA query (or close to it) will return true if the user has upvoted on the post comment and false otherwise:
select case when count(postCommentUpvote) > 0 then 'true' else 'false'
from PostCommentUpvote postCommentUpvote
join postCommentUpvote.postComment postCommnent
where postComment.id = :postCommentId
and user.id = :userId
You would then have to perform the same query using the PostCommentDownVote entity. An alternative would be to remove the up and down vote entities, simply create a PostCommentVote entity which has a boolean attribute that indicates up or down, and helper methods isUpvote() and isDownVote() that would interpret the boolean for you. You could get everything you need with a single query that returns a PostCommentVote if the user has up or down voted and null otherwise.
You did not indicate what you want to do if the user has already commented on the post; ignore the request or update the PostComment. Either way the most optimal way of doing this would be not checking at all. Create a unique index on (user_id, post_comment_id) or drop the the id column and make a composite PK of those columns. Then just insert without checking. Use the On Conflict to either ignore or update the request. You may also want to add an Up/Down vote indicator column.
Hello my professionals I have a simple question here that I would like to beg to solve this..
this is an Entity of Member
#Entity
#Getter
#Builder
#NoArgsConstructor(access = AccessLevel.PROTECTED)
#AllArgsConstructor
/*#ToString(of = {"id", "username", "age"})*/
public class Member {
#Id
/*#GeneratedValue(strategy = GenerationType.IDENTITY)*/
#Column(name = "member_id")
private Long id;
private String username;
private int age;
#OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "member")
private List<Team> teams;
#OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "member")
private List<Coach> coachs;
}
And this is an Entity of Coach
#Entity
#AllArgsConstructor
#Getter
#Builder
#Setter
#NoArgsConstructor
#ToString(of = {"id","name","career"})
public class Coach {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name= "coach_id")
private Long id;
#Column
private String name;
#Column
private String career;
#ManyToOne(fetch = FetchType.LAZY,cascade = ALL)
#JoinColumn(name = "member_id")
private Member member;
#OneToOne(fetch = FetchType.LAZY,cascade = ALL)
#JoinColumn(name = "team_id")
private Team team;
}
and This is Controller Code
#GetMapping("/member")
public void createUser(){
Member m = memberService.createMember();
Coach c = m.getCoachs().get(0);
log.info(c.getName());
}
and This is Service Code
private final MemberRepository memberRepository;
#Transactional
public Member createMember(){
return memberRepository.findMemberById(3L);
}
and the last this is RepositoryCode
Member findMemberById(Long id);
So my question is that when i printed out Coach's name at the controller on console
it printed out so well.
but what I know the Transaction is over from the service So the persistence container is closed that means coach name can't be imported cause it's LAZY loading and persistence container is closed but it was printed out well
I want to know the reason why ...
here are the console results Thanks !!
[2022-01-10 23:27:46.835] [http-nio-9000-exec-2] [] INFO o.a.c.c.C.[.[.[/] - Initializing Spring DispatcherServlet 'dispatcherServlet'
[2022-01-10 23:27:46.835] [http-nio-9000-exec-2] [] INFO o.s.w.s.DispatcherServlet - Initializing Servlet 'dispatcherServlet'
[2022-01-10 23:27:46.855] [http-nio-9000-exec-2] [] INFO o.s.w.s.DispatcherServlet - Completed initialization in 19 ms
Hibernate:
/* select
generatedAlias0
from
Member as generatedAlias0
where
generatedAlias0.id=:param0 */ select
member0_.member_id as member_i1_1_,
member0_.age as age2_1_,
member0_.username as username3_1_
from
member member0_
where
member0_.member_id=?
[2022-01-10 23:27:47.007] [http-nio-9000-exec-2] [4c0222d3] INFO p6spy - #1641824867007 | took 15ms | statement | connection 1| url jdbc:mariadb://patrick-lab.cjeq2ffynlc2.ap-northeast-2.rds.amazonaws.com:3306/patricklab?characterEncoding=UTF-8&serverTimezone=UTC
/* select generatedAlias0 from Member as generatedAlias0 where generatedAlias0.id=:param0 */ select member0_.member_id as member_i1_1_, member0_.age as age2_1_, member0_.username as username3_1_ from member member0_ where member0_.member_id=?
/* select generatedAlias0 from Member as generatedAlias0 where generatedAlias0.id=:param0 */ select member0_.member_id as member_i1_1_, member0_.age as age2_1_, member0_.username as username3_1_ from member member0_ where member0_.member_id=3;
[2022-01-10 23:27:47.170] [http-nio-9000-exec-2] [4c0222d3] INFO p6spy - #1641824867170 | took 12ms | commit | connection 1| url jdbc:mariadb://patrick-lab.cjeq2ffynlc2.ap-northeast-2.rds.amazonaws.com:3306/patricklab?characterEncoding=UTF-8&serverTimezone=UTC
;
Hibernate:
select
coachs0_.member_id as member_i4_0_0_,
coachs0_.coach_id as coach_id1_0_0_,
coachs0_.coach_id as coach_id1_0_1_,
coachs0_.career as career2_0_1_,
coachs0_.member_id as member_i4_0_1_,
coachs0_.name as name3_0_1_,
coachs0_.team_id as team_id5_0_1_
from
coach coachs0_
where
coachs0_.member_id=?
[2022-01-10 23:27:47.200] [http-nio-9000-exec-2] [4c0222d3] INFO p6spy - #1641824867200 | took 12ms | statement | connection 1| url jdbc:mariadb://patrick-lab.cjeq2ffynlc2.ap-northeast-2.rds.amazonaws.com:3306/patricklab?characterEncoding=UTF-8&serverTimezone=UTC
select coachs0_.member_id as member_i4_0_0_, coachs0_.coach_id as coach_id1_0_0_, coachs0_.coach_id as coach_id1_0_1_, coachs0_.career as career2_0_1_, coachs0_.member_id as member_i4_0_1_, coachs0_.name as name3_0_1_, coachs0_.team_id as team_id5_0_1_ from coach coachs0_ where coachs0_.member_id=?
select coachs0_.member_id as member_i4_0_0_, coachs0_.coach_id as coach_id1_0_0_, coachs0_.coach_id as coach_id1_0_1_, coachs0_.career as career2_0_1_, coachs0_.member_id as member_i4_0_1_, coachs0_.name as name3_0_1_, coachs0_.team_id as team_id5_0_1_ from coach coachs0_ where coachs0_.member_id=3;
[2022-01-10 23:27:47.213] [http-nio-9000-exec-2] [4c0222d3] INFO m.p.l.m.c.MemberController - Coach1
I believe it is because you are using the spring-boot default setting which the spring.jpa.open-in-view is set to true .
This property enables OpenSessionInView pattern which you can simply think that a transaction will be opened automatically for you at the very first beginning when processing any HTTP request (e.g. in the Servlet Filter etc). Because of this , a transaction is actually already open before your service method executes and it is still active after your service method completes. Hence you will not experience any LazyInitializationException even after you access non-initialized properties outside the service method as the transaction is still active.
There is a strong debate about whether or not spring-boot should enable it by default in the past . You can refer this for more details if you are interested. I personally would recommend to turn it off.
I'm using Hibernate Envers for Auditing Change Data, I have a Class that store information about companies like this :
#Getter
#Setter
#Entity
#Table(name = "COMPNAY")
#Audited
public class Compnay {
private String name;
private String code;
}
and it's using Envers for keeping the changes of companies.
also, I have a class for Keep the data of items that manufacture in any of this company, the class will be like this :
#Getter
#Setter
#Entity
#Table(name = "COMPNAY")
#Audited
public class Item {
#Column(name = "NAME", nullable = false)
private String name ;
#Column(name = "CODE", nullable = false)
private String code;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "COMPANY_ID", nullable = false)
private Compnay compnay;
}
Consider that there is a company in company table like this :
ID
NAME
CODE
1
Apple
100
2
IBM
200
and the data in the item's table will be like this :
ID
NAME
CODE
COMPANY_ID
3
iPhone
300
1
4
iPad
400
1
if I edit the information of Apple company and change the code from 100 to 300 how can I fetch the information of Items that were saved before this change with the previous code? Is there is any way to reference to audit table?
Yes, you can write a HQL query that refers to the audited entities. Usually, the audited entities are named like the original ones, with the suffix _AUD i.e. you could write a query similar to the following:
select c, i
from Company_AUD c
left join Item_AUD i on i.id.revision < c.id.revision
where c.originalId = :companyId
I'm using spring app with hibernate and postgres to store data. The configuration for the product entity is as follow :
/**
* A Product.
*/
#Entity
#Table(name = "product")
#Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
#Document(indexName = "product")
public class Product implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
#SequenceGenerator(name = "sequenceGenerator")
private Long id;
...
}
When I want to create a product using the web app I get the following error duplicate key value violates unique constraint. Detail : the key (id)=(35018) already exists.
From my understanding hibernate use a sequence in db to generate the next id value. So I did SELECT c.relname FROM pg_class c WHERE c.relkind = 'S'; in the psql shell to get all sequence in my db. The output is :
hibernate_sequence
jhi_user_id_seq
key_value_id_seq
jhi_persistent_audit_event_event_id_seq
unit_id_seq
generic_user_id_seq
currency_id_seq
customer_type_id_seq
customer_exploitation_type_id_seq
legal_entity_id_seq
deposit_id_seq
machine_id_seq
tank_id_seq
address_id_seq
product_id_seq
rewarded_file_id_seq
bar_code_type_id_seq
quality_label_id_seq
shop_pdv_id_seq
brand_id_seq
category_id_seq
material_id_seq
ws_call_id_seq
postal_code_id_seq
commune_id_seq
country_id_seq
event_id_seq
event_type_id_seq
key_blob_id_seq
card_id_seq
So I thought nice I have a product_id_seq and I only have to update the value in it for things to work.
But when I request the value with SELECT * FROM product_id_seq; I get :
last_value | log_cnt | is_called
------------+---------+-----------
100616 | 0 | t
So here I think that the id generated for the product id is not coming from this product_id_sequence since it tries to insert a product with id = 35018 and the product_id_seq last value is 100616.
So I wonder where does this id 35018 comes from? Which sequence is used to generate it? My guess is I have to update this mysterious sequence to get things to work. For info the hibernate sequence has a value of 36400.
Any idea that could get me going? Thanks in advance.
You do not map your sequence with postgre sequence so Hibernate creates the sequence hibernate_sequence (the one you got 35018 from) for itself.
To use your existing sequence:
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
#SequenceGenerator(name = "sequenceGenerator", sequenceName = "product_id_seq")
private Long id;
I faced the problem when I need to partially udate data in BD.
What I have:
I have three linked entities:
Profile --(1-m)--> Person --(1-1)--> Address
Where Person -> Address is lazy relationship. It was achieved via optional=false option (that allow hibernate to use proxy).
What the problem:
I need to update Profile in such way, that I needn't pull all Addresses that linked with this profile.
When I update Profile (don't work):
profile.setPersons(persons);
session.saveOrUpdate(profile);
throws: org.springframework.dao.DataIntegrityViolationException: not null property references a null or transient value
It happens because Person->Address relationship has optional=false option
I need to do:
//for each person
Address address = requestAddressFromDB();
person.setAddress(address);
persons.add(person)
//and only then
profile.setPersons(persons);
session.saveOrUpdate(profile);
profile.setPerson(person)
But I don't want to pull all address each time I update Profile name.
What is the question:
How can I avoid obligatory Person->(not null)Address constraint to save my profile without pulling all addresses?
ADDITION:
#Entity
public class Person{
#Id
#SequenceGenerator(name = "person_sequence", sequenceName = "sq_person")
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "person_sequence")
#Column(name = "id")
private long personID;
#OneToOne(mappedBy="person", cascade=CascadeType.ALL, optional = false, fetch = FetchType.LAZY)
private Address address;
//.. getters, setters
}
#Entity
public class Address {
#Id
#Column(name="id", unique=true, nullable=false)
#GeneratedValue(generator="gen")
#GenericGenerator(name="gen", strategy="foreign", parameters=#Parameter(name="property", value="person"))
private long personID;
#PrimaryKeyJoinColumn
#OneToOne
private FileInfo person;
}
Modify the cascade element on the #OneToOne annotation so that the PERSIST operation is not cascaded. This may require you to manually persist updates to Address in certain areas of your code. If the cascade is not really used however no change is needed.
#OneToOne(mappedBy="person", cascade={CascadeType.MERGE, CascadeType.REMOVE, CascadeType.REFRESH}, optional = false, fetch = FetchType.LAZY)
private Adress address; //Do you know that Address is missing a 'd'?