joinable.whereJoinFragment( rhsTableAlias, false, true )
);
}
private void renderCollectionJoin(Join join, JoinFragment joinFragment) {
final CollectionQuerySpace rightHandSide = (CollectionQuerySpace) join.getRightHandSide();
final CollectionReferenceAliases aliases = aliasResolutionContext.generateCollectionReferenceAliases(
rightHandSide.getUid(),
rightHandSide.getCollectionPersister()
);
// The SQL join to the "collection table" needs to be rendered.
//
// In the case of a basic collection, that's the only join needed.
//
// For one-to-many/many-to-many, we need to render the "collection table join"
// here (as already stated). There will be a follow-on join (rhs will have a join) for the associated entity.
// For many-to-many, the follow-on join will join to the associated entity element table. For one-to-many,
// the collection table is the associated entity table, so the follow-on join will not be rendered..
if ( rightHandSide.getCollectionPersister().isOneToMany()
|| rightHandSide.getCollectionPersister().isManyToMany() ) {
// relatedly, for collections with entity elements (one-to-many, many-to-many) we need to register the
// sql aliases to use for the entity.
//
// currently we do not explicitly track the joins under the CollectionQuerySpace to know which is
// the element join and which is the index join (maybe we should?). Another option here is to have the
// "collection join" act as the entity element join in this case (much like I do with entity identifiers).
// The difficulty there is that collections can theoretically could be multiple joins in that case (one
// for element, one for index). However, that's a bit of future-planning as today Hibernate does not
// properly deal with the index anyway in terms of allowing dynamic fetching across a collection index...
//
// long story short, for now we'll use an assumption that the last join in the CollectionQuerySpace is the
// element join (that's how the joins are built as of now..)
//
// todo : remove this assumption ^^; maybe we make CollectionQuerySpace "special" and rather than have it
// hold a list of joins, we have it expose the 2 (index, element) separately.
Join collectionElementJoin = null;
for ( Join collectionJoin : rightHandSide.getJoins() ) {
collectionElementJoin = collectionJoin;
}
if ( collectionElementJoin == null ) {
throw new IllegalStateException(
String.format(
"Could not locate collection element join within collection join [%s : %s]",
rightHandSide.getUid(),
rightHandSide.getCollectionPersister()
)
);
}
aliasResolutionContext.registerQuerySpaceAliases(
collectionElementJoin.getRightHandSide().getUid(),
new EntityReferenceAliasesImpl(
aliases.getElementTableAlias(),
aliases.getEntityElementColumnAliases()
)
);
}
addJoins(
join,
joinFragment,
(Joinable) rightHandSide.getCollectionPersister()
);
}