I trying to use EclipseLink JPA provider with H2 DBMS in Eclipse IDE.
When I create a new JPA project and fill the data (URL="jdbc:h2:~/test",Username="user",password="") connection type : resource local (I'm using the embedded mode)
I get 2 odd things :
when I try to create Entities from table I get a blank table list
I get an error message near #Entity notation saying that "catalog User can't be resolved for entity e1" or "Schema User can't be resolved for entity e1" depending on keeping the default value for catalog or changing it upon project creation where User is the database user name
The database already contains tables using the h2 console in Firefox
What is the cause of these problems and how can I solve it and do you have any page or book that can help with persistence.xml file (other than the oracle official web site)?
EclipseLink doesn't create the database tables for you, unless you explicitely tell it to do so.
The way to do that is described in the documentation
EclipseLink can be used to automatically generate the tables and database schema for a persistence unit. This is done through the "eclipselink.ddl-generation" persistence unit property, set to either "create-tables" or "drop-and-create-tables". The tables and constraints will be generated for all of the classes defined in that persistence unit.
The trick was to set the right catalog when creating the JPA Project and then every thing worked splendidly
Related
I'm working in a project where I'm supposed to read data from a database, called EBS, send it to the front-end and use it alongside other data to persist in another database. Let call it CPP.
The EBS must be read-only. Nothing should be persisted there. And they want all the specific queries to be stored in a xml file. For now, it's stored in the orm.xml.
I tried this solution, but it ended up creating a new table in the EBS and nothing was returned from CPP.
My questions are:
1 - How do a specify those native queries in orm.xml should be run in the EBS datasource? The datasource of CPP is in the application.properties file.
2 - Is it possible to JPA not create table with the #Entity annotation? Every time I use that, JPA ends up creating another table in the EBS. If not, is it possible to map the query directly to a POJO?
I would appreciate a solution based on JpaRepository. Thanks in advance.
There can be multiple persistence-unit in persistence.xml file but the name of those persistence units should be different .
If you don't want the entities to be created automatically then use application-managed entity manager
refter JPA application-managed entity manager
I'm using JPA Tools to generate the entity classes from an existing database following this tutorial:
http://o7planning.org/web/fe/default/en/document/7758/using-hibernate-tools-generate-entity-classes-from-tables
I setup the connection, but when I try to right-click on the project name > JPA Tools > Generate Entities from Tables, I select the connection and the schema, but no table is shown to select
but of course I have a few tables in the database with the same name. This is a picture from Sequel Pro:
Dali, the Eclipse plug-in that supplies the entity generation wizard you are using, relies on another Eclipse plug-in, DTP, to provide the database metadata necessary to perform the entity generation. As a result, this problem could be caused by either plug-in.
A simple way to (possibly) isolate the problem is to use DTP's Data Source Explorer view to see what DTP is returning in the way of metadata. Use this view to connect to your database. (You will be using the same connection profile you created in the Dali Entity Generation wizard.) Once you are connected you should be able to expand the tree to see your tables. If there are no tables, the problem is with the DTP adapter used to retrieve metadata from your database and this is a problem with DTP; if there are tables in the tree, the problem is with Dali.
Also, you should look at the Eclipse log (./.metadata/.log) to see if any sort of exception occurs when you are using the Dali wizard.
I'm trying to migrate an application from Hibernate 3.4.0.GA to Hibernate 5.1, and after complete the required changes on java code, when I deploy the application I'm watching how Hibernate is trying to create HT_ tables (global temporary), one for each #Inheritance annotated entity.
Searching on Google I've found why the tables are being created.
But in my case we are not allow to change de database to add new tables.
My Inheritance model only has one level of Inheritance and its simple, example
Does anyone knows any alternative representation for a hierarchical table structure that I can use to avoid the HT_ tables creation, or some Hibernate configuration to archive the same purpose?.
I can change the inheritance hierarchy on our entities or the Hibernate configuration. I can also asume an exception on deploy caused by the non creation of the tables if it´s non blocking for the rest of the deploy.
Thank you in advance.
UPDATE 1: New info from Hibernate official forum.
UPDATE 2: The Bug was fixed
UPDATE 3: A blog entry explaining different bulk Strategies related to the issue
As in update one on this link is more info from Hibernate official forum with a possible solution.
UPDATE: Link with the solution
If you use Oracle Database with Spring and not sure where to define property for hibernate can do the following.
Add
spring.jpa.properties.hibernate.hql.bulk_id_strategy: org.hibernate.hql.spi.id.inline.InlineIdsInClauseBulkIdStrategy
In application.yml file from resource folder.
I am new in the hibernate world. My project task is to represent xml result from the SQL database. To do so, first step, I am trying to generate POJOs and mapping xml from my db by using hibernate tools auto generating feature. When, i am trying to generate a simple database (2/3 tables) its working fine.
But while i trying to convert my real database, which has 28 tables within different table relationships. Then i am facing the below problem. Not able to connect the database tables. Hibernate tools configuration showing this terrible message.(Foreign key name (fk_p_einheit) mapped to different tables! previous: org.hibernate.mapping.Table(public.einheit_quelle) current:org.hibernate.mapping.Table(public.spalten)
I checked google to get the solution but not get any proper solution related to eclipse IDE. Just got one BUG report from NetBeans site(https://netbeans.org/bugzilla/show_bug.cgi?id=205863).
My setup configuration is:eclipse-jee-luna-SR1-win32-x86_64, postgres (sql 9.1-901.jdbc4) and hibernate core (4.3.5.Final) with maven project and hibernate tools.
Any one please help me.
You need an object model that maps all of those 28 tables and relationships. Do you have one? If not, why are you using Hibernate?
You can ask Hibernate to generate an object model for you from the schema. Try it.
Why are you using all these unknown technologies (Hibernate, Eclipse, etc.) to do something simple?
If you're thinking in terms of tables and columns, and not objects, I'd say you'd be better off writing JDBC and straight SQL. ORM tools aren't for you.
I'm learning how to use JPA with NetBeans/Glassfish.
I have created a new EE project, and some entities in the EJB. I also created a new database. While creating the entities I also created a new persistence unit. In Data Source I chosed "New data source", and for the database connection I used the one I've created just before.
But when I look in services to my database, I don't see any table corresponding to the entities. What should I do now?
Thanks for your help. And sorry if the question is obvious but I'm really new to this kind of programming.
JPA (2.1) allows you to create the schema appropriate for your JPA entities in your persistence-unit when the EntityManagerFactory is created. The linked page tells you what persistence properties to specify in your persistence-unit for this to happen automatically. (assuming your JPA implementation is for JPA version 2.1)