lib/sql.js
function(collectionName, where, key, parentKey) {
        return sql.build(collectionName, where, sql.predicate, ' AND ', undefined, parentKey);
    }
function(collectionName, where, key, parentKey) {
        return sql.build(collectionName, where, sql.predicate, ' AND ', undefined, parentKey);
    }
Starting point for predicate evaluation parentKey => if set, look for comparators and apply them to the parent key