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Re: [eclipselink-users] Load mapping file at "runtime"
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Hi Christian,
Is it possible to have multiple persitence units that have the same entities,
but different orm xml files that override the mappings and just select the
persistence unit that has the override you need.
It is possible to alter the underlying EclipseLink metadata after your
peristence unit is created, but you need to be careful because there is quite
alot of code that runs at initialization time to make sure everything is
consistence. Changing the field a BasicMapping maps to should be fairlyl easy,
but if you get into changing relationships mappings or mappings within
InheritanceHierarchies, you will have to be quite careful.
org.eclipse.persistence.jpa.JpaHelper has a getServerSession() method that
can get our underlying session. Session has a project and project has a list of
mappings that can be acquired by name. Changing the mappings is a matter of
calling the appropriate methods on the various mappings you get back.
-Tom
Christian August Michelsen wrote:
I'm having a wee bit trouble figuring out if and how I can specify a one
or more mapping-files based on some business logic when I create my
entitymanager (or before).
I basically have an entity where I have a string I'd like to map to
different kinds of columns (read only) based on some information I have
before I create my EMF and EM, but not at build/compile time.
So can one feed EclipseLink with the mapping files in any other way than
through the persistence.xml-file?
Some background:
The reason I want to do this is that I have an ecommerce app that I'm
connecting to. Now this web app has several different payment solutions
whereas they pretty much all create a one or more new columns in the
database. These of course have different names...
Now people usually only just use one of these payment solutions, so I
thought I'd support this by having some generic strings in my entity
class that maps to whatever column(s) the plugin adds. This way I don't
have to maintain different entities of an order just to support
different payment providers for instance.
