/** INTERNAL: Return if the expression is for a direct mapped attribute. */
public boolean isAttribute() {
if (isAttributeExpression == null) {
if (getSession() == null) {
// We can't tell, so say no.
return false;
}
QueryKey queryKey = getQueryKeyOrNull();
if (queryKey != null) {
isAttributeExpression = Boolean.valueOf(queryKey.isDirectQueryKey());
} else {
DatabaseMapping mapping = getMapping();
if (mapping != null) {
if (mapping.isVariableOneToOneMapping()) {
throw QueryException.cannotQueryAcrossAVariableOneToOneMapping(
mapping, mapping.getDescriptor());
} else {
isAttributeExpression = Boolean.valueOf(mapping.isDirectToFieldMapping());
}
} else {
isAttributeExpression = Boolean.FALSE;
}
}
}
return isAttributeExpression.booleanValue();
}
@Override
public ClassDescriptor getDescriptor() {
if (isAttribute()) {
return null;
}
if (descriptor == null) {
// Look first for query keys, then mappings. Ultimately we should have query keys
// for everything and can dispense with the mapping part.
ForeignReferenceQueryKey queryKey = (ForeignReferenceQueryKey) getQueryKeyOrNull();
if (queryKey != null) {
descriptor =
convertToCastDescriptor(
getSession().getDescriptor(queryKey.getReferenceClass()), getSession());
return descriptor;
}
if (getMapping() == null) {
throw QueryException.invalidQueryKeyInExpression(this);
}
// We assume this is either a foreign reference or an aggregate mapping
descriptor = getMapping().getReferenceDescriptor();
if (getMapping().isVariableOneToOneMapping()) {
throw QueryException.cannotQueryAcrossAVariableOneToOneMapping(getMapping(), descriptor);
}
descriptor = convertToCastDescriptor(descriptor, getSession());
}
return descriptor;
}