private String manyToManySelectFragment(
Joinable rhs, String rhsAlias, String lhsAlias, String collectionSuffix) {
SelectFragment frag = generateSelectFragment(lhsAlias, collectionSuffix);
String[] elementColumnNames = rhs.getKeyColumnNames();
frag.addColumns(rhsAlias, elementColumnNames, elementColumnAliases);
appendIndexColumns(frag, lhsAlias);
appendIdentifierColumns(frag, lhsAlias);
return frag.toFragmentString().substring(2); // strip leading ','
}
