I have a code that works perfectly on WAS 7 but fail when i run it in WAS 8.0.0.5. I am using JPA 2.0 with openJPA as my provider. Calling persist on my em throws a nested exception. Has anyone ever managed to write a JPA program in WAS 8.0.0.5
here is the Exception
WTRN0074E: Exception caught from before_completion synchronization operation: org.apache.openjpa.persistence.PersistenceException: DB2 SQL Error: SQLCODE=-204, SQLSTATE=42704, SQLERRMC=.OPENJPA_SEQUENCE_TABLE, DRIVER=3.58.81 {prepstmnt -1559269434 SELECT SEQUENCE_VALUE FROM .OPENJPA_SEQUENCE_TABLE WHERE ID = ? FOR READ ONLY WITH RS USE AND KEEP UPDATE LOCKS [params=?]}
The SQLCODE=-204 points that something is missing. The log keeps printing THAKHANI.OPENJPA_SEQUENCE_TABLE which makes think that maybe the table is missing. You could also check to make sure the DB2 user that JPA is using has permissions to create tables and run SELECT statements on them.
I manage to resolve the problem by selecting Identity as my primary key generation mechanism when generating entities from tables. I also add the following in my persistence.xml.
<properties>
<!-- OpenJPA specific properties -->
<property name="openjpa.TransactionMode" value="managed"/>
<property name="openjpa.ConnectionFactoryMode" value="managed"/>
<property name="openjpa.jdbc.DBDictionary" value="db2"/>
<property name="openjpa.jdbc.Schema" value=<SchemaName>/>
</properties>
Related
In persistence.xml I can declare the following :
<property name="eclipselink.ddl-generation" value="drop-and-create-tables" />
Is it possible to catch this event and execute code ?
I am running on glassfish 3.1.
JPA 2.1 has standard named properties. javax.persistence.schema-generation.database.action should be set to "drop-and-create" and javax.persistence.sql-load-script-source can be set to the name of a script file to load data. These are standard so should be in the docs for your JPA provider.
I am supposed to check for existence of tables on server startup. If they did not exist I have to create them using entity classes. Is this even possible?
I am using Eclipse and my server is wildfly10. I am connecting to Oracle 11g xe but I don't think it is database that is causing issues
Anyway, this is what I have done so far
My persistence.xml:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
xmlns="http://xmlns.jcp.org/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="Lab5">
<properties>
<property name="javax.persistence.schema-generation.database.action" value="create"/>
</properties>
</persistence-unit>
</persistence>
Without above property my database query throws Exception. But what is really strange, is that with this property query returns empty list, but table does not exist in database.
Also, I noticed warning showing on server startup
HHH000431: Unable to determine H2 database version, certain features may not work
I tried various fixes for this warning found on stackoverflow and other sites but they did not help. I don't even know if this is related to my problem
JPA 2.1 made DDL generation a part of the specification. You can use the "javax.persistence.schema-generation.database.action" persistence property with a "create" value to have 2.1 providers create the database schema for you during deployment. JPA can be used to generate or even run custom scripts should you need to modify the table creation/tear down and population process.
The problem you are likely encountering is your persistence unit does not specify a datasource, leaving it up to the container to figure out which you want to connect to, and Wildfly must be defaulting to an H2 database. The tables will be setup in this database, but not the Oracle XE database you are expecting - which is why queries return no values and yet in your console, the tables don't even exist.
You need to setup a datasource to your database in the server, and then point your persistence unit to it using the <non-jta-data-source> or <jta-data-source>. Your persistence.xml is incomplete, so I would urge you to look at a demo persistence unit first.
This will likely depend on the implementation you're including with your project. Assuming you're using hibernate for persistence, you'll need to add the following:
...
<persistence-unit ...>
<provider>org.hibernate.ejb.HibernatePersistence</provider>
...
<properties>
<property name = "hibernate.hbm2ddl.auto" value="create" />
...
</properties>
</persistence-unit>
Note that this will assume that your connection is formed with a user having the required privileges in the db for table creation. Take a look at the hibernate docs here.
My project involves JPA and following in my persistence.xml file
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
<persistence-unit name="rest-jpa">
<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
<jta-data-source>java:/comp/env/jdbc/restDB</jta-data-source>
<class>org.wso2.as.ee.Student</class>
<properties>
<property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)"/>
</properties>
</persistence-unit>
</persistence>
My H2 database is a in memory database.
It gives an error of table not found when I try to find for a record before adding one. I think that the table is created only when I add a record to the database. How can I create the table before any record is added?
You can make use of following JPA properties:
Generates and executes DROP TABLE and CREATE TABLE scripts everytime you run the application:
javax.persistence.schema-generation.database.action=drop-and-create
Loads some predefined data after creating database:
javax.persistence.sql-load-script-source="META-INF/loadData.ddl"
Creating schema should not be delayed until an entity is used (at least in case of using JPA), so you can use JPA properties which guarantee this behaviour. If you still find this behaviour occuring, you should make a bug ticket at your JPA provider bugtracker.
In my application we are using Toplink with Jpa.
Here the problem is we are using stored procedures in this application, we are taking the connection using Jndi connection for Stored Procedure calling, and we are using EntityManger for remaining queries. But here if we launching the application it is taking two connections from connection pool. After the application launching I am calling the Stored Procedure(sp)
one sp I am taking one connection but in websphere connection pool it is creating two connections?
can U plese help me how to overcome this problem.....
I won't using JTA, to get the JDBC connection I am using
EntityManager em = getJpaTemplate().getEntityManagerFactory().createEntityManager();
this way I am getting the JDBC Connection...and I configured the persitence.xml file following code...
<properties>
<property name="toplink.logging.level" value="OFF"/>
<property name="toplink.cache.type.default" value="NONE"/>
<property name="com.thoughtinc.runtime.persistence.sql.syntax" value="db2" />
</properties>
So, please kindly look into this and tell me any if I am doing any wrong here.
Are you using JTA or non-JTA? Are you releasing the connection back to the pool after using it?
Depending on your configuration (include your persistence.xml), if you have a non-JTA login configured TopLink may use this for non-transactional read queries. This is configurable in your persistence.xml.
To get the JDBC Connection from a TopLink (EclipseLink) EntityManager use em.unwrap(Connection.class)
I am having problems connecting to 2 persistence units from within the same transaction using following tech stack,
WLS 10.3.x, Eclipselink 2.1, Oracle 11g JDBC driver, Informix 10 JDBC driver
Using inputs from this SO post I made the oracle datasource XA compliant and the Informix ds "Emulate 2-phase commit" and things started to work. However, now I am getting a strange problem.
I am using standalone java client to invoke my ejb 3 SLSB which in turn invokes the JPA entities. The problem I am facing is it works the first time, the second time it does not throw any exception but does not update the data in either databases and the 3rd time it throws an exception stating "Transaction has already been committed" as if the application server JTA transaction manager is holding on to the original transaction context. Please note these 3 invocations are separate and sequential wherein every invocations completes with the client exiting the client process. The problem is very consistent and happens in the exact same sequence every time I restart the app server.
Appreciate any input!
<persistence-unit name="TopLinkDB" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>jdbc/oracleDS</jta-data-source>
<class>com.home.domain.Property</class>
<properties>
<property name="eclipselink.target-server" value="WebLogic_10" />
</properties>
</persistence-unit>
<persistence-unit name="TopLinkINFO" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>jdbc/infoDS</jta-data-source>
<class>com.home.domain.GlobalNumber</class>
<properties>
<property name="eclipselink.target-server" value="WebLogic_10" />
</properties>
</persistence-unit>