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Re: [eclipselink-users] Should selection criteria be set after adding the join attributes?

Hi Rohit,

I am a bit surprised ".anyOf("empinfo.phone.empid")" works at all. I would expect you to have to write something like: "get("empinfo").anyOf("phone").get("empid") - i.e. When using the expression API, you should not use the "." notation within the method calls.

-Tom

Rohit Banga wrote:

Hello All

I have a phone table and an employee table. The phone table has a foreign key constraint on the employee id. An employee can have multiple phones.

Now when I query for a employee having phone number say '11' I set the selection criteria as:


query.setSelectionCriteria( query.getExpressionBuilder().anyOf("empinfo.phone.empid").get("phone").equal("11"));


I add the following join attribute:

query.addJoinAttribute(query.getExpressionBuilder().anyOf("empinfo.phone.empid"));

_Case 1:_ If I set the selection criteria before adding the join attribute the query generated is:

select * from empinfo t0, phone t1 where t0.empid=t1.empid and t1.phone='11'

which does not return all the phone numbers of the employee having phone number '11'.

_Case 2_: If I set the selection criteria after adding the join attribute the query generated is:

select * from empinfo t0, phone t1, phone t2, where t0.empid=t1.empid and t1.phone='11' and t2.empid=t0.empid

which returns all the phone numbers of the employee having phone number '11'.

Also in case 1 if I generate the query for the second time with the same session, the query of case 2 is generated, however again not all phone numbers of the employee having phone number '11' are generated (*perhaps due to caching?*)

If I do not set any selection criteria the first time I query, then all the information is returned the first time as expected. If I now use the sequence of Case 1 for creating a query in the same session then the correct result is obtained. *How to explain this?*

*Is this behavior expected? Why is it important to add the join attribute before setting the selection criteria?*
*Could you please point me to the relevant documentation?*


Thanks in Advance!

--
Thanks and Regards
Rohit Banga
Member Technical Staff
Oracle Server Technologies


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