Cayenne 1.1
MySql 4.1.8
Hi Everybody,
I want to find the entries that do not occur in intersection tables, so in
SQL:
select *
from pva_fotos
where id not in (select fto_id from pva_wng_fto)
and id not in (select fto_id from pva_cpx_fto)
The JavaCode that came close to this was:
[...]
SelectQuery qry = new SelectQuery (Foto.class);
SelectQuery qryCfi = new SelectQuery (Foto.class);
Expression qc1 = Expression.fromString("toCpxFtoRelaties");
qryCfi.setQualifier(qc1);
List lstCfi = mContext.performQuery(qryCfi);
SelectQuery qryWfi = new SelectQuery (Foto.class);
Expression qw1 = Expression.fromString("toWngFtoRelaties");
qryWfi.setQualifier(qw1);
List lstWfi = mContext.performQuery(qryWfi);
Expression qCpxFto = null;
if (lstCfi.size() > 0)
{
qCpxFto = ExpressionFactory.notInExp("<what to say here?>", lstCfi);
qry.setQualifier(qCpxFto);
} //if
if (lstWfi.size() > 0)
{
Expression qWngFto = ExpressionFactory.notInExp("<what to say here?>",
lstWfi);
if (qCpxFto != null)
{
qry.andQualifier(qWngFto);
} //if
else
{
qry.setQualifier(qWngFto);
} //else
} //if
List lst = mContext.performQuery(qry);
[..]
Can someone answer the following questions for me? :
- What should I insert at the "<what to say here?>" part? I want to compare
that object to the current List.
- Is there a more efficient way to handle subselects? If my approach is
correct, large resultsets of the subselects could become problematic.
Thanks in advance, Laszlo
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