You mean something like this (fetch is needed to prevent select n + 1
problem)?
var entries = (from o in session.Query<LastOpened<Customer>>().Fetch(x
=> x.Entity)
from c in session.Query<Customer>()
where o.Entity.Id == c.Id
select o).ToArray();
This results in the following (wrong and extremly ugly) SQL:
LastOpened o left outer join
Customers c1 left outer join
JoinTable1 j1 left outer join
JoinTable2 j2 inner join
Customers c2 left outer join
JoinTable1 j3 left outer join
JoinTable2 j4,
Customers c3 left outer join
JoinTable1 j5 left outer join
JoinTable2 j6
where c2.Id = c3.Id
The JoinTables are coming from my <join> elements in the Customer
entity.
On Jul 12, 12:01 pm, Ricardo Peres <[email protected]> wrote:
> cremor:
>
> Have you tried this?
>
> var q = (from a1 in session.Query<Entity>()
> from a2 in
> session.Query<Entity>()
> where a1.Id == a2.Id
> select a1.Id +
> a2.Id).ToList();
>
> On Jul 12, 8:11 am, cremor <[email protected]> wrote:
>
>
>
>
>
>
>
> > I need an inner join for the query itself, the fetch is just an
> > additional requirement to prevent a select n + 1 problem.
>
> > Concrete use-case:
> > A table that saves the last 100 opened customers for each user. This
> > table has a reference to the customer table. The customer table has
> > limited access (by Oracle FGAC) which prevents access to customer rows
> > which the user isn't allowed to see. It could happen that a user is
> > moved to another security group which then suddenly results in the
> > user having last-opened-entries for customers he hasn't access to
> > anymore. Therefore I have to query the last opened table with an inner
> > join to the customers table so that only rows are returned which the
> > user has access to. The fetch is needed because I have to show the
> > customer names in a list in the UI.
>
> > This is supported by HQL and Criteria perfectly, just seems like it
> > isn't yet implemented for Linq.
>
> > On Jul 12, 8:00 am, CSharper <[email protected]> wrote:
>
> > > The question for me is why do you want NHibernate to perform an INNER
> > > JOIN. If you want a correct result in the general case without the not
> > > null constraint, an outer join is required. And if you have a not null
> > > constraint and a foreign key, a good query planner should detect the
> > > situation and optimize the query the same way as if it would have been
> > > an outer join in the first place.
>
> > > On 10 Jul., 20:16, cremor <[email protected]> wrote:
>
> > > > If it should be that way it isn't working. It's still a left outer
> > > > join when I set the many-to-one to not-null (using 3.2.0.CR1).
>
> > > > On 8 Jul., 23:38, Ricardo Peres <[email protected]> wrote:
>
> > > > > The INNER JOIN or the LEFT OUTER JOIN is selected depending on which
> > > > > the endpoint of the relation can be null (not-null="true" or not-
> > > > > null="false" in the hbm.xml mappings).
>
> > > > > On Jul 8, 11:45 am, cremor <[email protected]> wrote:
>
> > > > > > Is it possible to modify a query (or the mapping) so that the call
> > > > > > to
> > > > > > the .Fetch() extension method of NHibernate results in a inner join
> > > > > > in
> > > > > > the generated SQL query?
>
> > > > > > In HQL or QueryOver this is easy, but I couldn't find that for Linq.
>
> > > > > > A workaround seems to be writing the join myself in the Linq query,
> > > > > > but then all <join> elements in the entity are joined twice (very
> > > > > > ugly
> > > > > > and inefficient SQL).
--
You received this message because you are subscribed to the Google Groups
"nhusers" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/nhusers?hl=en.
