[
https://issues.apache.org/jira/browse/JDO-652?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16601154#comment-16601154
]
Andy Jefferson edited comment on JDO-652 at 9/2/18 12:52 PM:
-------------------------------------------------------------
Re: mail to jdo-dev mailing list (which I don't subscribe to, and besides this
is the issue in JIRA so ought to be the focal point for any dev discussion
specific to this API),
*IF-THEN-ELSE* : this was added to JDOQL after the JDOQLTypedQuery API was
designed. Consequently there is no handling for it. What QueryDSL does is
likely the best option to use as a guide for how to provide it (see
[http://www.querydsl.com/static/querydsl/4.1.3/reference/html_single/#d0e2105]
and
[http://www.querydsl.com/static/querydsl/4.1.4/apidocs/com/querydsl/core/types/dsl/CaseBuilder.html]
). Adapting it to JDO we could have something like this. Create a
CaseExpression via builder method on JDOQLTypedQuery
CaseExpression caseExpr = JDOQLTypedQuery.newCaseExpression();
and then have methods on CaseExpression to
CaseExpression when(BooleanExpression condition, Expression valueExpr);
CaseExpression else(Expression valueExpr);
Or go via the QueryDSL CaseBuilder idea? If you have a better idea, propose
something?
*Ordering NULLS FIRST/LAST* : again, not part of JDOQL when this API was
designed. So we could do something like this
OrderExpression
public enum OrderNullsPosition
{ FIRST, LAST }
/**
* Accessor for the position of nulls with this expression.
* @return The nulls position (or null if not defined)
*/
OrderNullsPosition getNullsPosition();
/**
* Method to set nulls to be ordered BEFORE non-nulls.
* @return The order expression
*/
OrderExpression<T> nullsFirst();
/**
* Method to set nulls to be ordered AFTER non-nulls.
* @return The order expression
*/
OrderExpression<T> nullsLast();
If you have a better idea, propose something?
*Map.get(Expression<K>)* : Was only added to JDOQL later in the dev cycle, so
just add it?
*sqrt(), abs() etc for primitive wrappers* : A primitive wrapper is a
NumericExpression, so are already part of the API. You likely need
_datanucleus-jdo-query v5.0.6_ to see them, but that is not an error in the
API, just the implementation having them later.
*StringExpression.startsWith(String, int)* : Was only added to JDOQL later in
the dev cycle, so just add it. And while at it add the equivalent(s) taking in
StringExpression, and NumericExpression.
was (Author: andy):
Re: mail to jdo-dev mailing list (which I don't subscribe to, and besides this
is the issue in JIRA so ought to be the focal point for any dev discussion
specific to this API),
*IF-THEN-ELSE* : this was added to JDOQL after the JDOQLTypedQuery API was
designed. Consequently there is no handling for it. What QueryDSL does is
likely the best option to use as a guide for how to provide it (see
[http://www.querydsl.com/static/querydsl/4.1.3/reference/html_single/#d0e2105]
and
[http://www.querydsl.com/static/querydsl/4.1.4/apidocs/com/querydsl/core/types/dsl/CaseBuilder.html]
). Adapting it to JDO we could have something like this. Create a
CaseExpression via builder method on JDOQLTypedQuery
CaseExpression caseExpr = JDOQLTypedQuery.newCaseExpression();
and then have methods on CaseExpression to
CaseExpression when(BooleanExpression condition, Expression valueExpr);
CaseExpression else(Expression valueExpr);
Or go via the QueryDSL CaseBuilder idea? If you have a better idea, propose
something?
*Ordering NULLS FIRST/LAST* : again, not part of JDOQL when this API was
designed. So we could do something like this
ComparableExpression
/**
* Method to set nulls to be ordered BEFORE non-nulls.
* @return The order expression
*/
OrderExpression<T> nullsFirst();
/**
* Method to set nulls to be ordered AFTER non-nulls.
* @return The order expression
*/
OrderExpression<T> nullsLast();
OrderExpression
public enum OrderNullsPosition
{
FIRST,
LAST
}
/**
* Accessor for the position of nulls with this expression.
* @return The nulls position (or null if not defined)
*/
OrderNullsPosition getNullsPosition();
If you have a better idea, propose something?
*Map.get(Expression<K>)* : Was only added to JDOQL later in the dev cycle, so
just add it?
*sqrt(), abs() etc for primitive wrappers* : A primitive wrapper is a
NumericExpression, so are already part of the API. You likely need
_datanucleus-jdo-query v5.0.6_ to see them, but that is not an error in the
API, just the implementation having them later.
*StringExpression.startsWith(String, int)* : Was only added to JDOQL later in
the dev cycle, so just add it. And while at it add the equivalent(s) taking in
StringExpression, and NumericExpression.
> Provision of a typesafe 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
> Assignee: Michael Bouschen
> Priority: Major
> Fix For: JDO 3.2
>
> Attachments: JDO-652-api-patch-Andy.txt, JDO-652-patch3.txt,
> typesafe.patch, typesafe_manifest.patch
>
>
> 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
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
