Eclipse Community Forums: EclipseLink » 2 or more constraints when doing anyOf

Help

Home

Home » Eclipse Projects » EclipseLink » 2 or more constraints when doing anyOf

Show: Today's Messages :: Show Polls :: Message Navigator

2 or more constraints when doing anyOf [message #1048620]

Wed, 24 April 2013 18:36

brad Mising name

Messages: 17
Registered: February 2010

Junior Member

In the documentation there is a note about using .anyOf twice in an Expression. The note mentions "you would use a single anyOf and a temporary variable" as a work around. I haven't seen any examples of this being done in the documentation. Does anyone have an example? I could be overlooking something simple here...

Link to Documentation:
http://wiki.eclipse.org/Introduction_to_EclipseLink_Expressions_(ELUG)#Using_EclipseLink_Expression_API_for_Joins

Thanks
-Brad

Report message to a moderator

Re: 2 or more constraints when doing anyOf [message #1048662 is a reply to message #1048620]

Wed, 24 April 2013 19:51

Chris Delahunt

Messages: 1389
Registered: July 2009

Senior Member

Reuse the result of expression.anyOf() rather than call it again, the same way you would store the result of a get accessor method rather than repeatedly calling get for the value.

Instead of
ExpressionBuilder builder = new ExpressionBuilder();
Expression whereClause = builder.anyOf("projects").get("name").equal("Enterprise").or(builder.anyOf("projects").get("name").equal("Server"));
you would use:
ExpressionBuilder builder = new ExpressionBuilder();
Expression projects = builder.anyOf("projects");
Expression whereClause = projects.get("name").equal("Enterprise").or(projects.get("name").equal("Server"));

In the first example, you are making 2 different joins from the root over the projects collection, while in the second there will only be a single join what will check if name=Entierprise or name=Server.

Best Regards,
Chris

Report message to a moderator

Re: 2 or more constraints when doing anyOf [message #1049311 is a reply to message #1048662]

Thu, 25 April 2013 17:16

brad Mising name

Messages: 17
Registered: February 2010

Junior Member

Thanks for the tip, I will try that out. I also ran across an example in the documentation of something like this:
ExpressionBuilder subject = new ExpressionBuilder();
ExpressionBuilder name = new ExpressionBuilder();
ReportQuery subQuery = new ReportQuery(Name.class, name);

subQuery.retrievePrimaryKeys();
subQuery.setSelectionCriteria(
name.equal(subject.anyOf("names")).and(
name.get("first").toUpperCase().equal(firstName.toUpperCase())).and(
name.get("last").toUpperCase().equal(lastName.toUpperCase()))
);

This also got me the results I was looking for. The example I used is found in the javadoc for Expression. allOf.

Thanks
-Brad

Report message to a moderator

Re: 2 or more constraints when doing anyOf [message #1775224 is a reply to message #1048662]

Thu, 26 October 2017 13:37

thorsten kruse

Messages: 6
Registered: October 2017

Junior Member

I think, there is something wrong when conforming results in unit of work. Please have a look at stackoverflow.com questions/46936336/eclipselink-how-to-use-expression-anyof-with-cache

Report message to a moderator

Previous Topic:	Please refactor code - use sonar -EntityManagerSetupImpl - PreDeploy has 400 lines of code
Next Topic:	<property name="eclipselink.canonicalmodel.generate_timestamp" value="false"/

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

]

Current Time: Sat Apr 20 03:19:37 GMT 2024

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter