Eclipselink and update trigger on multiple access to the database

» java » Eclipselink and update trigger on multiple access to the database

By : Wassim HABBOUB

Date : January 10 2021, 01:47 PM

may help you . One solution I have seen used is to use triggers in the database to send a JMS message to your application. The message is then received in a MDB where the EclipseLink cache can be invalidated or refreshed. This approach works well on an Oracle database where the trigger drops messages into an AQ table.
The are DBMS specific solutions I am familiar with but the challenge is always to get the change notification to include the table and PK values instead of a ROWID and also to ensure you are not being notified of changes you made yourself or have some way to easily filter out notices from your own changes.

code :

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How to access multiple tenants in eclipselink?

By : WDL

Date : March 29 2020, 07:55 AM

Any of those help EclipseLink has an open feature request to allow a better way of allowing an admin server to access multi tenant data: https://bugs.eclipse.org/bugs/show_bug.cgi?id=355458 - vote for it if it is important to you.
The way around it would be to create a separate persistence unit for your admin console. One way to go about this would be to move the multitenant metadata to an EclipseLink orm.xml file, and use it in your tenant persitence units, while the admin persistence unit just use the entity classes. You might want a field in the entities that can be mapped to the tenant column that the admin console could use and query against, but be read-only or inaccessible to the tenant specific persistence units.

Access to Derby database from another project using EclipseLink

By : user2947128

Date : March 29 2020, 07:55 AM

Hope this helps Since you're using a relative filename in your jdbc.url (databases/bDb), Derby is looking for the database relative to your application start directory.
And your two separate applications have two separate directories in which they are being run.

I'm trying to update 2 fields in multiple tables in my database using a trigger after inserting a new row

By : anonymous

Date : March 29 2020, 07:55 AM

Hope that helps There are several issues with your trigger code.
1) The purpose of this part of the code is unclear :

code :

BEGIN
    SELECT fillHist_station FROM DUAL;
END;

CREATE OR REPLACE TRIGGER tr_update_solde_nbreserv
AFTER INSERT ON RESERVATION
FOR EACH ROW
BEGIN 
    UPDATE CLIENTS
    SET NB_RESERV = NB_RESERV+1 , SOLDE = SOLDE+1
    WHERE numc = :new.numc; 
END tr_update_solde_nbreserv;
/

How update the database using a web service and EclipseLink as JPA provider?

By : Petr Svobodnik

Date : March 29 2020, 07:55 AM

To fix this issue You need to call commit() to commit the transaction. Executing a query will not commit.
What type of transactions are you using? JTA or RESOURCE_LOCAL? If you are using JTA, then you must use JTA to begin a commit transactions.

Accessing multiple database from a Java web application using JPA/EclipseLink/EJB

By : David Rodriguez

Date : March 29 2020, 07:55 AM

Does that help We faced the same use case and ended up creating multiple persistence-unit and building an entity manager factory which returns the correct entity manager according to an parameter sent by the client (as an enum in our case, Environment). Then, instead of injecting the persistence context in the clients, we inject this factory and call getEntityManager(environment).