Unfortunately, in this case, you can't necessarily. One of the issues here is that holding on to handles to multiple collections doesn't do what it seems to, and also doesn't fail. Try running this:

    var low = require('lowdb');

    var foo = low('foo');
    low('bar');

    low.on('add', function(collection) {
        console.log("this should be foo:", collection);
    });

    foo.insert({ name: 'foo' });

  low('foo').insert({ name: 'foo' })
  low('bar').insert({ name: 'bar' })
  low('foo').insert({ name: 'foo' })

But I can see that it's a flaw and unexpected behavior. I'm adding this to the enhancements for the next version.

Thanks for spotting it :)

It fixes some initial flaws/bugs and includes some new features. Also, writing is now fault-tolerant and fully asynchronous.