Re: [hibernate-dev] Pull request for HHH-2394 (Support filter tag in subclass)

'deduceAliasInjectionPoints' is important when you don't have injections. Otherwise Hibernate ends up scanning the condition fragment for no reason. On Fri 22 Jun 2012 11:09:31 AM CDT, Rob Worsnop wrote: > On Mon, Jun 4, 2012 at 12:14 PM, Steve Ebersole <steve(a)hibernate.org&gt; > wrote: > >> 1) I think adding support for {alias} is a more general issue. Its >> applicable to many other pieces of mapping metadata (@Formula, etc). >> More I >> was responding to David's comment there. I totally think it makes sense >> to >> support this in all of those cases. I guess the vote point there is >> whether >> we want to introduce that support piecemeal or develop it across the >> board. >> If we do do it piecemeal I think another piece of information we will >> need >> is a flag indicating whether to scan for alias injection points. By >> "scanning" I mean the processing we do today where we tokenize the >> fragment >> string and then try to guess where an alias is needed. Let's call this >> flag 'deduceAliasInjectionPoints' for now. I tend to favor meaningful >> attribute names so my suggested names tend to get a little long; I am >> open >> to suggestions for a more succinct name. Anyway, I think it needs to be >> TRUE by default to maintain backwards compatible behavior. Here is an >> example: >> >> @Filter(name="iqMin", table="ZOOLOGY_HUMAN", condition="{alias}.HUMAN_IQ >> >= >> :min", deduceAliasInjectionPoints=**false) >> >> Here there is no need to deduce the points at which to inject an alias; >> we >> have done that for Hibernate in the supplied condition fragment. >> >> I think another discussion revolves around cases in which the fragment >> involves references to columns from multiple tables. Mostly this is >> important for scenarios involving secondary tables and inheritance. Do >> we >> want to provide support for that? Using the classic >> org.hibernate.test.hql.Animal hierarchy from the testsuite, maybe >> something >> like: >> >> @Filter( >> name="iqMin", >> condition="{a}.bodyWeight >= :minWeight and {m}.birthdate < >> :ageCutOffBirthDate", >> deduceAliasInjectionPoints=**false, >> aliases={ >> @SqlFragmentAlias( alias="a", entity=Animal.class ), >> @SqlFragmentAlias( alias="m", entity=Mammal.class ) >> } >> ) >> >> > How about just applying the secondary table usage to everything? > > So, to rewrite your first example: > > @Filter(name="iqMin", condition="{h}.HUMAN_IQ >=> :min", > aliases={@SqlFragmentAlias( alias="h", table="ZOOLOGY_HUMAN" )}) > > Note that I didn't include "deduceAliasInjectionPoints". Wouldn't we > just infer that from the presence of the aliases element? > -- steve(a)hibernate.org http://hibernate.org