How to do transactions with indexedDb using promises?

getExample.js

// Using moreUsable.js style
indexedDB.open(DBNAME, DBVERSION, DBSCHEMA)
.then(function(connection) {
  return connection.transaction(["table1"]) // undefined -> readonly, state undefined also
  .then(function(obj) {
    return obj.transaction.get(obj.state, "table1", "foo");
  })
  .then(function(obj) {
    return obj.state;
  });
})
.then(function (value) {
  console.log("everything went ok, got value", value);
}, function(e) {
  console.error("something failed", e);
});

moreUsable.js

indexedDB.open(DBNAME, DBVERSION, DBSCHEMA)
.then(function(connection) {
  return connection.transaction(["table1", "table2"], {}, true) // true for readwrite, {} for initial state
  .then(function(obj) {
    return obj.transaction.get(obj.state, "table1", "foo");
  })
  .then(function(obj) {
    var newState = _.extend({}, obj.state, { foo: obj.value });
    return obj.transaction.add(newState, "table2", { id: "bar", value : value.bar });
  })
  .then(function(obj) {
    // don't do anything with state anymore, just return it
    return obj.state;
  });
})
.then(function (state) {
  console.log("everything went ok, got state", state);
}, function(e) {
  console.error("something failed", e);
});

/* I miss do-notation from Haskell. */