You are right. I completely misread that. I'd still probably do raw
SQL or an SQLTemplate, though.
Thanks,
/dev/mrg
On Thu, Mar 6, 2008 at 3:31 PM, Mike Kienenberger <mkienen..mail.com> wrote:
> Michael, just to clarify, he doesn't want to work with Employees. He
> wants to work with Departments. Scott wants to know how to do this
> without pulling in the Employee records.
>
>
>
> On 3/6/08, Michael Gentry <blacknex..mail.com> wrote:
> > If it is mandatory, it sounds like these records were created outside
> > of Cayenne (they are legacy, testing, etc records)? If that is the
> > case, the easiest thing to do is to just issue an SQL command directly
> > to the database (using whatever normal SQL command you use).
> > Something like:
> >
> > delete from employee where departmentFK is null;
> >
> > If it is something that is happening regularly, though, and you want
> > to be able to nuke them from within your Cayenne application, you can
> > issue raw SQL to do the trick, too:
> >
> > DataContext dataContext = DataContext.createDataContext();
> > SQLTemplate sqlQuery = new SQLTemplate(Customer.class, "delete from
> > employee where departmentFK is null");
> > dataContext.performNonSelectingQuery(sqlQuery);
> >
> > With this code, though, be careful that you don't have any of those
> > dangling employees in memory, as this totally bypasses the Cayenne
> > object graph.
> >
> > /dev/mrg
> >
> >
> >
> > On Thu, Mar 6, 2008 at 3:19 PM, Scott Anderson <sanderso..irvana.com> wrote:
> > > Employee.Department is mandatory; I want to search for and delete rogue
> > > departments.
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Michael Gentry [mailto:blacknex..mail.com]
> > > Sent: Thursday, March 06, 2008 2:08 PM
> > > To: use..ayenne.apache.org
> > > Subject: Re: Get the number of FKs
> > >
> > > It seems you mainly want a list of employees who are not in a
> > > department, so doing a fetch on Employee where "department = null"
> > > might work (I'm not positive I've ever tried this, but it seems logical
> > > to me).
> > >
> > > /dev/mrg
> > >
> > > On Thu, Mar 6, 2008 at 1:58 PM, Scott Anderson <sanderso..irvana.com>
> > > wrote:
> > > > I've got a one-to-many relationship (employees belong to a
> > > > department), and I'd like to search for departments that have no
> > > employees.
> > > > Currently, I have something like:
> > > >
> > > > foreach(dept : departments) {
> > > > if(dept.getEmployees().size() == 0)
> > > > context.deleteObject(dept);
> > > > }
> > > >
> > > > When I do this, it has the effect of telling Cayenne to fetch data
> > > > rows for every employee in the database; this will not scale well. Is
> > >
> > > > there any way I can get the size of the array without doing a custom
> > > > SELECT query?
> > > >
> > >
> >
>
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