About expression


ObjectDB Object Database Features

ObjectDB provides a rich set of features, many of them as the result of supporting the JPA and JDO APIs. ObjectDB provides a rich set of features. Many features are implemented as part of ObjectDB's support of the JPA JPA Reference (JavaDoc) Java/JPA API Reference (based on the JPA 3 JavaDoc) See JavaDoc Reference Page... an ...



Release date: 2011-04-22 Download (5.07 MB) Binary:  objectdb-2.2.2.zip You should start by following a  tutorial or reading the manual ...



Release date: 2012-05-20 Download (5.4 MB) Binary:  objectdb-2.4.0.zip You should start by following a  tutorial or reading the manual ...



The Selection interface defines an item that is to be returned in a query result.(Interface of JPA)


[ObjectDB 2.5.5_03] Unexpected exception (Error 990)

Hello! When I run this query SELECT t FROM Unit t WHERE t.lastGeocodedPosition IS NULL OR t.lastGeocodedPosition.receiveTime < :lastGeocodedPosition.receiveTime I get the following exception: ... It seems that the expression in the WHERE clause fails with NPE for all the objects, and ... are returned from the query. If it was a Java expression you wouldn't have NPE, because OR is evaluated from left to ...



... Added support of using list of literals in an query IN expression. Added the ability to disable hollow objects . ...



Return the ordering expressions in order of precedence.(Method of javax.persistence.criteria.CriteriaQuery)


Issue with DISTINCT Select

It is getting more and more frustrating :( We've introduced distinct select instead of regular selection in our code (no changes else) and suddenly receive invalid identifiers in queries exceptions in various queries. Here's the stacktrace: ... Caused by: com.objectdb.o.UserException: Invalid order expression '$3' for distinct results at ... are strict rules regarding what is allowed in the ORDER BY expression. You didn't provide a query so it is impossible to say if the ...


LEFT JOIN FETCH over empty embedded collection returns no results

First of all, thank you for promptly implementing JOIN FETCH over nested paths in response to my inquiry a few months ago. However, I have run into one problem: if an embedded collection is empty, but I attempt to LEFT JOIN FETCH all the members of a collection within a (non-existent) member of the first collection, the result of the overall query is an empty set. To use the example from my original post: @Embeddable class A { String val; };   ... The problem may be with the expression  c.bList.val . Path expressions are considered as INNER JOIN ...


Chapter 4 - JPA Queries (JPQL / Criteria)

Describes the Java Persistence Query Language (JPQL), the JPA Criteria API, and explains how to use queries in JPA. The JPA Query Language (JPQL) can be considered as an object oriented version of SQL. Users familiar with SQL should find JPQL very easy to learn and use. This chapter explains how to use JPQL as well as how to use the JPA Criteria API, which provide ...