Skip to content

JDO Sample showing "fetch-fk-only" extension on a 1-1 relation (FK) field

Notifications You must be signed in to change notification settings

andyjefferson/jdo-fetch-fk-only

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

5 Commits
 
 
 
 
 
 
 
 

Repository files navigation

jdo-fetch-fk-only

Sample showing usage of the member metadata extension "fetch-fk-only" used on a 1-1 (FK) field requesting that any retrieval only pull back the FK and avoid the join to the related object (table). This will instantiate the related object but just not populate it (other than its identity field(s)).

The query is SELECT FROM mydomain.model.Person

which is compiled to SELECT 'mydomain.model.Person' AS DN_TYPE,A0.ADDRESS_ID_OID,A0.ID,A0."NAME" FROM PERSON A0

So no JOIN is created. It then instantiates Person and Address objects.

Object "mydomain.model.Person@455351c4" (id="mydomain.model.Person:1") added to Level 1 cache (loadedFlags="[NYN]")  
Object "mydomain.model.Address@379ab47b" (id="mydomain.model.Address:1") added to Level 1 cache (loadedFlags="[YN]")  
Object "mydomain.model.Address@379ab47b" (id="mydomain.model.Address:1") added to Level 2 cache (fields="[0]", version="")  
Object "mydomain.model.Person@455351c4" (id="mydomain.model.Person:1") added to Level 2 cache (fields="[0, 1, 2]", version="")  
p=Person [1] address=mydomain.model.Address@379ab47b  

About

JDO Sample showing "fetch-fk-only" extension on a 1-1 relation (FK) field

Resources

Stars

Watchers

Forks

Releases

No releases published

Packages

No packages published

Languages