We Keep Coding

Finding the name of the column in which duplicate value was inserted

In hibernate for columns annotated with #Column(unique = true) we get an exception when trying to insert a duplicate value for that column.
2022-07-31 19:47:18.112 ERROR 14372 --- [io-8080-exec-10] o.h.engine.jdbc.spi.SqlExceptionHelper : Duplicate entry ' someValue' for key 'business.UK_3h6o7iww8015m4q3yffbkqtrw'
So from the above log, I know that business is the table in which I am inputting a duplicate value.
Is there a way to know in which column the duplicate value is getting inserted into? Since a single table can have multiple unique columns.

In addition to what Davide D'Alto wrote, you can also enable SQL logging, e. g. as shown here.

You can check the SQL for the table creation:
show create table business;
or you can run the following query:
select COLUMN_NAME
from information_schema.KEY_COLUMN_USAGE
where TABLE_NAME = 'business' and CONSTRAINT_NAME='UK_3h6o7iww8015m4q3yffbkqtrw'

Eclipse link JPA - Get only entity of associated table records

I am new to JPA. In my new project, we are using Eclipse Link JPA.
I have two tables. Students, Addresses. Each student may have multiple addresses(For address history). So one to many relationship. In StudentEntity.java file, I mentioned Set.
Now my question is, whenever I am fetching all student details, inside Set, I needed only one Addressed entry, based on created date in addresses table. That means When I fetch List using createQuery, how can I mention, associated table conditions.
Example:-
StudentEntity
STUDENT1 --- John
STUDENT2 --- Robert
Addresses
Addr_id - STU_ID -- Addr1 --City ---created date
1 - STUDENT1 -- latestadd --latestcity -- 23-8-2017
2 - STUDENT1 -- oldaddr --oldcity -- 12-8-2016
Student:-
#OneToMany()
Set adddresses;
So when i don createQuery("select s from Students"), i want to get only address having addr_id = 1 which is latest address.
How can i achieve this using createQuery?

Got the required result with below query
Student s join s.addresses a where a.id = 1" is giving result and also, for "#OneToMany" annotation we need to give "#JoinFetch".

Use createQuery("select s from Students where addr_id = 1")
As far as i can tell this is what you are asking for

Hibernate to get max id and store it in memory

I am new to using hibernate. I have written the following code get the max id in my order table.
public int getOrderMaxUID() {
Session session = sessionFactory.getCurrentSession();
String query = "SELECT max(o.UID) FROM Order o";
List list = session.createQuery(query).list();
int maxOrderUID = ((Integer) list.get(0)).intValue();
return maxOrderUID;
}
and I call this method in my controller before I add a new record to the table.
orderService.getOrderMaxUID();
orderService.add(o);
The Issue : Records are added to our Order table by other processes as well. So to avoid Duplicate PK issue, I get the max id from the order table before inserting record. But I still get following error when other process add records
2013-04-04 09:27:24,841 WARN ["ajp-bio-8009"-exec-2] org.hibernate.util.JDBCExceptionReporter - SQL Error: 2627, SQLState: S1000
2013-04-04 09:27:24,841 ERROR ["ajp-bio-8009"-exec-2] org.hibernate.util.JDBCExceptionReporter - Violation of PRIMARY KEY constraint 'PK_Order'. Cannot insert duplicate key in object 'Order'. The duplicate key value is (1001508).
and
org.springframework.dao.DuplicateKeyException: Hibernate flushing: could not insert:
I want hibernate to store the id retrieved by getMaxOrderId() method in memory and use the next number as when adding new record.
Any help on this would be appreciated.

Why don't you get Hibernate to just generate the ID for you?
/** The id. */
#Id #GeneratedValue
private Long id;
EDIT:
You can create entries from multiple processes as long as you do it through hibernate and the id's will be adjusted accordingly.
Inserting into the database outside of hibernate however, will cause you issues. You may be able to use a Customer ID Generator to work around this. I found this example that may help
If you edit the database outside of hibernate, you may run into other problems as well (particularly if you use the second level cache for example)
If you use the same Session, you will run into issues caused by the first level cache as well.

JPA: querying FK

I'm using EclipseLink(JPA 2.0) under Netbeans 7.0 with JDK 7. Adding more, this is a JavaSE.
I have this tables, Employee and Record where in the relation is Employee(1) --- (*)Records.
Adding more about the structure of the Record: RecordID (PK), EmployeeID(FK), Status, etc.
I wanted to query out from the Record Table (not using the Employee->Rental Collection) what records has a relation with the employee..
I tried using the query, it always returns an exception
Exception Description: Error compiling the query [SELECT r FROM Record r WHERE
r.employeeid = :employeeid], unknown state or association field
[employeeid] of class [Record].

From the information given it's not completely clear, but I believe you need to reference the id inside the Employee object.
eg. the correct query is probably:
SELECT r FROM Record r WHERE r.employee.id = :employeeid
(notice the extra dot in employee.id)
If this doesn't work, please provide us with some actual code of your Java classes.

"No row with the given identifier exists" although it DOES exist

I am using Hibernate and getting
Exception in thread "main" org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [#271]
What is pretty weird about this error is, that the object with the given id exists in the database. I inserted the problematic record in another run of the application. If I access it in the same run (i.e. same hibernate session) there seem to be no problems retrieving the data.
Just because it could be a fault of the mapping:
public class ProblemClass implements Persistent {
#ManyToOne(optional = false)
private MyDbObject myDbObject;
}
public class MyDbObject implements Persistent {
#OneToMany(mappedBy = "myDbObject")
private List<ProblemClass> problemClasses;
#ManyToOne(optional = false)
private ThirdClass thirdClass;
}
I have absolutely no clue even where to look at. Any hints highly appreciated!
Just to clarify:
The data was inserted in another RUN of the application. It is definitely in the database, as I can see it via an SQL-Query after the application terminated. And after THAT, i.e. when starting the application again, I get the error in the FIRST query of the database -- no deletion, no rollback involved.
Addition:
Because it was asked, here is the code to fetch the data:
public List<ProblemClass> getProblemClasses() {
Query query = session.createQuery("from ProblemClass");
return query.list();
}
And just to make it complete, here is the generic code to insert it (before fetching in another RUN of the application):
public void save(Persistent persistent) {
session.saveOrUpdate(persistent);
}

Eureka, I found it!
The problem was the following:
The data in the table ThirdClass was not persisted correctly. Since this data was referenced from MyDbObject via
optional = false
Hibernate made an inner join, thus returning an empty result for the join. Because the data was there if executed in one session (in the cache I guess), that made no problems.
MySQL does not enforce foreign key integrity, thus not complaining upon insertion of corrupt data.
Solution: optional = true or correct insertion of the data.

Possible reasons:
The row was inserted by the first session, but transaction was not committed when second session tried to access it.
First session is roll-backed due to some reason.

Sounds like your transaction inserting is rollbacked

Main reason behind this issue is data mismatch, for example i have entity mapping class called "X" and it has column "column1" and it has reference to the table "Y" column "column1" as below
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "column1", referencedColumnName = "column1")
public Y getColumn1() {
return Y;
}
In this if X table column1 has value but Y table column1 is not having the value. Here link will be failed.
This is the reason we will get Hibernate objectNotFound exception
This issue can also be resolved by creating proper data model like creating proper indexing and constraints (primary key/foreign key) ..

This might be your case, kindly check my answer on another post.
https://stackoverflow.com/a/40513787/6234057
I had the same Hibernate exception.
After debugging for sometime, i realized that the issue is caused by the Orphan child records.
As many are complaining, when they search the record it exists.
What i realized is that the issue is not because of the existence of the record but hibernate not finding it in the table, rather it is due to the Orphan child records.
The records which have reference to the non-existing parents!
What i did is, find the Foreign Key references corresponding to the Table linked to the Bean.
To find foreign key references in SQL developer
1.Save the below XML code into a file (fk_reference.xml)
<items>
<item type="editor" node="TableNode" vertical="true">
<title><![CDATA[FK References]]></title>
<query>
<sql>
<![CDATA[select a.owner,
a.table_name,
a.constraint_name,
a.status
from all_constraints a
where a.constraint_type = 'R'
and exists(
select 1
from all_constraints
where constraint_name=a.r_constraint_name
and constraint_type in ('P', 'U')
and table_name = :OBJECT_NAME
and owner = :OBJECT_OWNER)
order by table_name, constraint_name]]>
</sql>
</query>
</item>
2.Add the USER DEFINED extension to SQL Developer
Tools > Preferences
Database > User Defined Extensions
Click "Add Row" button
In Type choose "EDITOR", Location - where you saved the xml file above
Click "Ok" then restart SQL Developer
3.Navigate to any table and you will be able to see an additional tab next to SQL, labelled FK References, displaying FK information.
4.Reference
http://www.oracle.com/technetwork/issue-archive/2007/07-jul/o47sql-086233.html
How can I find which tables reference a given table in Oracle SQL Developer?
To find the Orphan records in all referred tables
select * from CHILD_TABLE
where FOREIGNKEY not in (select PRIMARYKEY from PARENT_TABLE);
Delete these Orphan records, Commit the changes and restart the server if required.
This solved my exception. You may try the same.

Please update your hibernate configuration file as given below:
property start tag name="hbm2ddl.auto" create/update property close tag

I have found that in Oracle this problem can also be caused by a permissions issue. The ProblemClass instance referred to by the MyDbObject instance may exist but have permissions that do not allow the current user to see it, even though the user can see the current MyDbObject.