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https://issues.apache.org/jira/browse/JDO-652?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12926213#action_12926213
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Andy Jefferson edited comment on JDO-652 at 10/30/10 1:40 PM:
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Re: developing model and query objects, if someone wants to give it a try they
can put
"datanucleus-jdo-query.jar" (available in the DN nightly repo) in the Eclipse
annotation processor jar list, enable JDK1.6 compliance, and also have
"datanucleus-core.jar" in the CLASSPATH. They can then create a model class
(e.g Product.java) and start writing persistence code that refers to QProduct,
such as
QProduct qp = QProduct.candidate;
and start making references to "qp" and its various methods ... see
http://datanucleus.blogspot.com/2010/07/jdo-typesafe-refactorable-queries.html
for the expressions. This is the basis for the various clauses of the proposed
query API
Note this is not currently a full working prototype, it just allows creation of
the dynamic query objects and can demonstrate the access of fields, use of
methods and relations etc. An example of the API as currently in DataNucleus SVN
Query<Product> q = pm.newTypesafeQuery(Product.class);
QProduct cand = QProduct.candidate;
q.filter(cand.value.lt(40.00).and(cand.name.startsWith("Wal"))).orderBy(cand.name.asc());
List<Product> results = q.executeList();
The "Query" object here is a different class to the javax.jdo.Query, could be
renamed TypesafeQuery for example. The user can also type "q.toString()" to see
the single-string equivalent.
was (Author: andy):
Re: developing model and query objects, if someone wants to give it a try
they can put
"datanucleus-jdo-query.jar" (available in the DN nightly repo) in the Eclipse
annotation processor jar list, enable JDK1.6 compliance, and also have
"datanucleus-core.jar" in the CLASSPATH. They can then create a model class
(e.g Product.java) and start writing persistence code that refers to QProduct,
such as
QProduct qp = QProduct.candidate;
and start making references to "qp" and its various methods ... see
http://datanucleus.blogspot.com/2010/07/jdo-typesafe-refactorable-queries.html
for the expressions. This is the basis for the various clauses of the proposed
query API
Note this is not currently a full working prototype, it just allows creation of
the dynamic query objects and can demonstrate the access of fields, use of
methods and relations etc.
> Provision of a statically-typed refactor-friendly query capability for JDOQL
> ----------------------------------------------------------------------------
>
> Key: JDO-652
> URL: https://issues.apache.org/jira/browse/JDO-652
> Project: JDO
> Issue Type: New Feature
> Components: api, specification, tck
> Reporter: Andy Jefferson
> Fix For: JDO 3 maintenance release 1
>
>
> There are various querying capabilities of this type around. JPA2 has its
> Criteria query API. Third party solutions like QueryDSL also exist, in its
> case providing a JDOQL implementation (as well as JPQL, and HQL). We should
> seriously consider introducing something along these lines in the JDO2.4
> timeframe.
> There is a comparison of JPA Criteria with QueryDSL over at
> http://source.mysema.com/forum/mvnforum/viewthread_thread,49
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