Hi David,
Thanks for the response! I tried the findAll() method. It is
definitely simpler than creating a SQL query with an IN clause. When
an entity is not in the datacache, one SQL statement is generated per
object. But at least, the code is simpler...
Could there be an existing option to adjust this behavior? Something
that would allow me to say fetch X rows instead of just one...
Christian
On 7/18/07, David Ezzio <[EMAIL PROTECTED]> wrote:
Hi Christian,
You might consider using the OpenJPAEntityManager.findAll method. The
expected advantage is that any objects in the datacache won't cause a
hit to the database. If there is a high likelihood that all objects are
in the datacache, then this is definitely the way to go. If some
objects will very likely not be in the cache, then you might want to
investigate. I'm not sure whether it will generate one SQL statement
for all missing objects or one for each. You might want to turn on SQL
logging to check,
((OpenJPAEntityManager) em).findAll(...)
Hope this helps,
David
Christian Defoy wrote:
> Hello,
>
> I can't find an easy way of retrieving a group of entities by
> specifying only their IDs. For example, if I want to get shapes with
> IDs 1, 2, 4 and 6, do I have to do the following query or is there a
> better way?
>
> SELECT x FROM shape x WHERE x.id = 1 OR x.id = 2 OR x.id = 4 OR x.id = 6
>
> I was thinking of something more along the lines of the IN SQL
> statement ("WHERE x.id IN (1,2,4,6)") but I haven't found anything to
> do this. Using SQL queries, I was able to retrieve my shapes but
> OpenJPA does one select to retrieve the IDs (my SQL query with the IN
> clause) and then one select per shape it retrieves. That is no
> different than me doing a find for every shape myself...
>
> Thanks in advance!
>
> Christian
>
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