node.js - use cradle to delete db but cache didn't reset

Question

I use node 0.8.18, express3.2.5, cradle0.6.6. my problem is : after I saved a doc into db, then I delete db to reset my testcase env, but when I save the doc with the same id, cradle told me that doc is exsited! source code as follow:

Repository = new(cradle.Connection)().database(REPOSITORY_NAME_STRING);
...
Repository.save(id, acct, function(err, reply){
        if(err) {
            errorHandler('POST /guests', JSON.stringify(err));
            aEvents.emit('a_aborted', req, res, id);
        } else {
            db.destroy(function(){
                Repository = new(cradle.Connection)().database(REPOSITORY_NAME_STRING);
                Repository.create(function(){                                      
                    /* populate design documents */                             
                    populateDesignDocuments();                                  
                        Repository.get(id,function(err, doc){
                            if(err && err['error']=='not_found') {
                                aEvents.emit('a_notFound', id, acct);
                            } else {
                                aEvents.emit('a_existed', req, res, id);
                            }
                        });
                });                                                             
            });
        }
    }

then I got the same acct document, it seems still in the cradle cache.

can I clean the cache the same time I delete the db ?