How to avoid dependency on Hibernate in business objects

joshua_fox · **Joined:** Thu Nov 04, 2004 10:24 am **Posts:** 17

Some methods in my business objects must load data through queries rather than direct Hibernate-mapping.

E.g., a

Code:

Department

class has methods

Code:

getEmployees()

and

Code:

getSalary()

which are mapped to the DB using Hibernate.

There is another method

Code:

getHighSalariedEmployees()

which returns employees with salaries greater than 100,000. I can execute an HQL query inside getHighSalariedEmployees() .

But I don't want query-definition and -execution code inside my business object Department.

Suggestions?

anthony · **Posted:** Thu Dec 23, 2004 4:50 am

Quote:

There is another method getHighSalariedEmployees()
which returns employees with salaries greater than 100,000. I can execute an HQL query inside getHighSalariedEmployees() .

But I don't want query-definition and -execution code inside my business object Department.

Suggestions?

MVC / DAO mismatch
you can access data layer from your domain model but everyone will advise you not to do it for a lot of good reasons.

3 solutions with Hibernate 2:
- let hibernate retrieve the full list and lets filter it in java (not really performant depending on list size)
- map a second collection with a "where saliaries > 100000" clause
- just let the controller do this stuff, it's exactly what it should do

2 bests solutions with hibernate 3:
- use dynamic filter
- use lazy formula property
these two features are EXCELLENT and solve the data access problems

chainsaw · **Posted:** Thu Dec 23, 2004 8:55 am

Yes, but then H3 must be available

anthony · **Posted:** Thu Dec 23, 2004 9:17 am

again:
- just let the controller do this stuff, it's exactly what it should do

emmanuel · **Posted:** Thu Dec 23, 2004 1:48 pm

chainsaw wrote:

Yes, but then H3 must be available

H3 is due to Q1 2005 and is ready for development