In already existing table structure inheritance I am adding a new column type (I cut some of the code)
#Entity
#Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class Account {
......
#Column // already existed column
private String name; // get/set also applied
#Column(length=20) // new added column
#Enumerated(EnumType.STRING) // get/set also applied
private AccountType type;
..........
}
#Entity
public User extends Account {
................ // some other already existed fields
}
In my persistence.xml file I am using next strategy policy for DDL generation
property name="eclipselink.ddl-generation" value="drop-and-create-tables"
When DDL generation is processing the new added column type in Account table is successfully created, BUT for User table there is no such kind of column at all (the strategy is TABLE_PER_CLASS).
I fixed that when i drop the database and created it again. After that the current generation of DLL was applied - type in User is also added as a column. Does someone "met" with such kind of issue ? I fixed with with drop and create of the DB but I am not sure that should be the strategy in same cases in future, specially for production DB
Thanks,
Simeon Angelov
DDL generation is for development not production. The problem you are seeing is because when the table already exists, it cannot be created with the new field. Drop and create or the "create-or-extend-tables" feature will work if you are adding to the tables as described here http://wiki.eclipse.org/EclipseLink/DesignDocs/368365
Related
I am following the example provided here by eclipselink.
When I start my tests, it fails with:
javax.persistence.RollbackException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.7.1.v20171221-bd47e8f):
org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: org.postgresql.util.PSQLException: ERROR: relation "event_history" does not exist.
The framework isn't creating the table as I would expect. I have the following configuration:
<property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
From this link, I don't feel it's necessary to add the DescriptorCustomizer class to the persistence.xml file. But I may be wrong.
My question is, do I have to create the table manually? Or I am doing something wrong? The examples I found relative to the feature are quiet poor.
Some solutions are discussed in eclipse link forum.
Clovis Wichoski CLA Friend 2016-01-02 15:29:19 EST
The problem still occurs with 2.6.2
Follow a StringTemplate to be used to easy the creation by hand (for Postgres database)
CREATE TABLE <tableName>_audit (
LIKE <tableName> EXCLUDING ALL,
audit_date_start timestamp,
audit_date_end timestamp
)
Here is another possible solution:
Peter Hansson CLA Friend 2016-03-25 05:30:42 EDT
Yes, I've had the same issue.
I've explored a couple of avenues in order to get EclipseLink to generate the history tables for me (so that they always reflect their base table). I haven't been able to come up with a method that would work, less one that would be db agnostic.
I do believe the only way to solve this is in the core of EclipseLink, for example by adding a new annotation, #HistoryTable.
I'm thinking something along the lines of the following:
Suppose you have base class, Person:
#Entity
public class Person {
#Id
private Long personId;
private String firstName;
private String lastName;
..
}
Then we could define a history entity for that entity as follows:
#Entity
#HistoryTable(base=Person.class, primaryKeyFields="personId,rowStartTime")
public class PersonHist {
// Add here the extra fields/columns that should exist for the
// history table.
private Date rowStartTime;
private Date rowEndTime;
..
}
The #HistoryTable annotation would replicate all fields from the base entity, including most field annotations, except for annotations related to relations, which wouldn't be relevant on the history table.
By definition the history table's primary key will always be a composite of columns in the base table, typically it will be like in the example. In the example the PersonHist entity will think it has an #Id notation on fields personId and rowStartTime. (yeah, this area needs more brain work :-))
I am working with jpa 2.0 and I have a field in a table of the database that has value by default, I put that field in my definition of entities as insertable = false so that when inserted retain the default value, the insert is done correctly but when requery the object that field is null in the entity, however, that it has been inserted correctly.
This is my code:
#Entity
#Table(name="SOME_TABLE")
public class SomeTable implements Serializable {
private static final long serialVersionUID = 1L;
#EmbeddedId
private SomeTablePK id;
#Column(name="X1")
private String x1;
**#Column(name="X2", insertable=false)**
private Date x2;
... more fields....
... setters and getters...
}
there any way to force the entity manager to refresh the value of the field that I used as insertable = false? or what can i do to fix it?
Thank you very much.
PS. It is important to mention that in my persistence.xml and place the following line to disable the cache.
<properties>
<property name="javax.persistence.sharedCache.mode" value="NONE"/>
</properties>
You will need to invoke manually the refresh after the flush operation.
The Spec (3.2.4 Synchronization to the Database) says that:
The state of persistent entities is synchronized to the database at transaction commit. This synchroniza- tion involves writing to the database any updates to persistent entities and their relationships as speci- fied above.
An update to the state of an entity includes both the assignment of a new value to a persistent property or field of the entity as well as the modification of a mutable value of a persistent property or field[28].
Pay attention below:
Synchronization to the database does not involve a refresh of any managed entities unless the refresh operation is explicitly invoked on those entities or cascaded to them as a result of the specification of the cascade=REFRESH or cascade=ALL annotation element value.
Given the Model:
Public Class Customer
Property Id() As Guid
Property FirstName() As String
Property MiddleName() As String
Property LastName() As String
Property Addresses() As ICollection(Of Address)
End Class
Public Class Address
Property Id() As Guid
Property Name() As String
Property Street() As String
Property City() As String
Property Zip() As String
Public Property Customer() As Customer
End Class
Entity Framework 6 Code First has created a column called Customer_Id in my table Addresses. Now, I'd like to add a Property Customer_Id to my class Address that represents the existing foreign key relation:
Public Class Address
Property Id() As Guid
Property Name() As String
Property Street() As String
Property City() As String
Property Zip() As String
Public Property Customer() As Customer
//Added
Public Property Customer_Id() As Guid
End Class
Unfortunately this results in an InvalidOperationException while creating the DbContext saying:
The model backing the 'DataContext' context has changed since the database was created.
I tried different property names (with and without underscore, different casing). But still no luck. So, what is the correct way to add those properties subsequently without the need for migrations? I assume it's possible, because the model does not really change, I am only changing from an implicit declaration of a property to an explicit...
Update:
The responses show me, that I did not explain the problem very well. After some more reading I found the correct names now: I have an application which is installed several times at customer locations (therefore dropping and recreating the database is no option). Currently, it depends on Entity Framework's Independent Associations, but I want to have the Foreign Key in my entity as well (this is no change to the model, the foreign key is already there, but does not exist as a property in my entity, since this is currently only relying on the IA instead). I did not manage to add it without EF thinking my Database is outdated.
for me two ways :
drop table __MigrationHistory : that is have the new model runs, but forget migration functionalities
create a new db by changing the connection string of the application. Replace old __MigrationHistory by __MigrationHistory of the newly created db
Never tested the second solution, but it should work.
Before using any solution:
backup you db.
Before using first solution: are you sure you will never need migration functionalities ?
This exception is because you change your model. You have to set migration strategy. Please look at:
http://msdn.microsoft.com/en-us/data/jj591621#enabling
(edited)
First of all you have to remove that exception. Even if you didn't add any new column to your database your model has changed because you added new property to Address class. If you check your DB you will find dbo.__MigrationHistory table with Model column. Last (earliest) value from that column is used for checking that your model and DB are compatible. I'm not sure but I think that EF stores there binary serialized model. So the solution is - recreate DB or add migration (probably empty migration).
(edited)
When you want to set FK you can do this very simple by Data Annotations
// c# example
public class Address
{
...
public string CustomerId { get; set; }
[ForeignKey("CustomerId")]
public Customer Customer { get; set; }
}
or in fluent api
// c# example
modelBuilder.Entity<Address>()
.HasRequired(arg => arg.Customer)
.WithMany()
.HasForeignKey(arg => arg.CustomerId);
or look at:
http://weblogs.asp.net/manavi/archive/2011/05/01/associations-in-ef-4-1-code-first-part-5-one-to-one-foreign-key-associations.aspx
http://msdn.microsoft.com/en-us/data/hh134698.aspx
I'm using spring data (jpaRepository) + Oracle 11g Database.
Here's the code of my JUnit test:
#Test
public void testAjoutUtilisateur() {
Utilisateur utilisateur = new Utilisateur();
(...)
utilisateur=repository.save(utilisateur);
Utilisateur dbutilisateur = repository.findOne(utilisateur.getIdutilisateur());
assertNotNull(dbutilisateur);
When I debug I find that "utilisateur" object returned by repository.save method has an id like "2100" while the corresponding inserted line in the database have an id like "43".
I have an Oracle database with a sequence and a trigger to have the auto incremented property for the id for my "Utilisateur" table.
Here is the id definition in my Utilisateur entity:
#Entity
#NamedQuery(name="Utilisateur.findAll", query="SELECT u FROM Utilisateur u")
#SequenceGenerator(sequenceName="ID_UTILISATEUR_SEQ", name="ID_UTILISATEUR_SEQ")
public class Utilisateur implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="ID_UTILISATEUR_SEQ")
private Long idutilisateur;
Where is the problem? Is it within the save method?
Thank you.
Edit:
I figured out that the problem was already solved by the solution of #jhadesdev and the data lines I was talking about were inserted when the triggers were actives.
Finally, I have to mention that by default the JUnit test seems to not insert data in the database (it inserts then rollback). In order to invalidate this behaviour we have to specify the #TransactionConfiguration(defaultRollback=false) annotation in the test class.
For example (in my case):
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = { "classpath:context/dao-context.xml" })
#TransactionConfiguration(defaultRollback=false)
#Transactional
public class UtilisateurRepositoryTest {
Hope it can help someone.
The problem is that two separate mechanisms are in place to generate the key:
one at Hibernate level which is to call a sequence and use the value to populate an Id column and send it to the database as the insert key
and another mechanism at the database that Hibernate does not know about: the column is incremented via a trigger.
Hibernate thinks that the insert was made with the value of the sequence, but in the database something else occurred. The simplest solution would probably be to remove the trigger mechanism, and let Hibernate populate the key based on the sequence only.
I am working with Eclipselink and having issue with using secondary table.
I have two tables as below.
Student with columns student_id(Primary Key), student_name etc.
Registration with columns student_id(FK relationship with Student table), course_name (with not null constraint) etc.
The requirement is student may or may not have registration. If student has registration, the data should be persisted to Registration table as well. Otherwise only Student table should be persisted.
My code snippet is as below.
Student.java
------------
#Entity
#Table(name = "STUDENT")
#SecondaryTable(name = "REGISTRATION")
#Id
#Column(name = "STUDENT_ID")
private long studentId;
#Basic(optional=true)
#Column(name = "COURSE_NAME", table = "REGISTRATION")
private String courseName;
I tried the following scenarios.
1. Student with registration - Working fine. Data is added to both Student and Registration tables
2. Student without registration - Getting error such as 'COURSE_NAME' cannot be null.
Is there a way to prevent persisting into secondary table?
Any help is much appreciated.
Thanks!!!
As #Eelke states, the best solution is to define two classes and a OneToOne relationship.
Potentially you could also use inheritance, having a Student and a RegisteredStudent that adds the additional table. But the relationship is a much better design.
It‘s possible using a DescriptorEventListener. The aboutToInsert and aboutToUpdate callbacks have access to the DatabaseCalls and may even remove the statements hitting the secondary table.
Register the DescriptorEventListener with the ClassDescriptor of the entity. For registration use a DescriptorCustomizer specified in a Customizer annotation at the entity.
However, you will not succeed fetching the entities back again later on. EclipseLink uses inner joins when selecting from the secondary table, so that the row of the primary table will be gone in the results.