google chrome extension - IndexedDB range limits -

i'm using indexeddb store person's city, email id , created_at. want people in city valid email , sort created_at date.

i have compound index query so:

var     city = "chennai"; var     index_name = "city, " + "email, " + "created_at"; var     index   = store.index(index_name); var     boundedkeyrange = idbkeyrange.bound([city, "", 0], [city, ??, ""]);  index.opencursor(boundedkeyrange, "prev").onsuccess = function(e) {     var cursor = e.target.result;      if  (cursor) {          // check if email valid , add array     }     else {           // resolve promise     } } 

the problem have don't know how set 'upper range' email id's since @ special character i'm not sure set upper range have email ids in query.

thank you

deepak

the upper bound of string can taken '\uffff' or [].

anyways, query not work because have 2 range query, "email" , "created_at". can have 1 key range query.