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Possible issue for JPQL IS EMPTY expression

Possible issue for JPQL IS EMPTY comparison expression: SELECT e FROM MyEntity e WHERE e.collection-valued IS EMPTY throws javax.persistence.PersistenceException: Invalid operand type  for operator IS EMPTY (error 756) Thanks. #1 2012-04-19 09:29 Possible issue for JPQL IS EMPTY comparison expression: SELECT e FROM MyEntity e WHERE e.collection-value ...

 
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Index on map key

Is there a way to create an Index with @Index on the key of a map? #1 2013-10-02 06:10 Is there a way to create an Index with @Index on the key of a map? ...

 
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Sorting problem

Hi, I was rewriting our DAO to support pagging in large dataset and I think I have found a problem with sorting. I send you a test case - sorry for using the same project as previous, but it was faster to write this test case. As usual, you can load data with DataLoader and then check problem with QueryData. There is a simple query with "order by" sentence: #1 2011-02-13 00:04 Hi, I was rewriting our DAO to support pagging in large dataset and I think I have found a problem with s ...

 
tutorial

Step 3: Define an EJB Session Bean

Explains how to define an EJB session bean in an Eclipse Java EE 6 web application. Operations on the database will be performed by an instance of a session bean (EJB) class that we will define in this step: Open the [New Java Class] dialog box by right clicking the guest package node (in the [Package Explorer] window) and selec ...

 
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No clue how to query with collection

Hi there! Actually, what I have is something like: @Embedable class Address { String getStreet(); int getStreetNo(); } @Entity class Contact { Collection<Address> getAddresses(); }   #1 2011-12-02 15:55 Hi there! Actually, what I have is something like: @ Embedable class Address { ...

 
tutorial

Step 3: Define a Spring DAO Component

Explains how to define a JPA DAO component (bean) in a NetBeans Spring MVC JPA web application project. Operations on the database will be performed by an instance of a Data Access Object (DAO) that we will define in this step as a Spring MVC component: Open the [New Java Class] dialog box by right clicking the guest packa ...

 
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String Encoding Issue

Hi all Encounter a character encoding issue when i try to retrieve a String column containing Chinese character. Retrieve a String column on odb file.  em = emf.createEntityManager(); Query query = em.createQuery("SELECT fu FROM FarmUnit fu"); But, when try to print the value out as: #1 2011-06-23 04:30 Hi all Encounter a character encoding issue when i try to retrieve a String column containing Chinese cha ...

 
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Multi-tenant setup

Hi, does anybody have experience with multi tenant setup of objectDB. For example using multiple schema or multiple database. How to handle connections between app (Jboss Wildfly) and pass query request to appropriate database, how to dynamically add new database or schema. There are lot of discussions on how to do it with hibernate Thanks     ... Java classes for the common data and maps (as persistent fields) to store specific tenant data as key/value pairs. ...

 
tutorial

Step 3: Define a Spring DAO Component

Explains how to define a JPA DAO component (bean) in an Eclipse Spring MVC JPA web application project. Operations on the database will be performed by an instance of a Data Access Object (DAO) that we will define in this step as a Spring MVC component: Open the [New Java Class] dialog box by right clicking the guest packa ...

 
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Internal objectdb error when open a database or open an entity manager

we get following exception when we open a database or open an entity manager   ... 2.6.6 (probably when there are classes with no persistent fields in the hierarchy). Build 2.6.6_07 should fix this exception. ...