There is no documentation about the usage of QueryBuilder.

[thvd]

No description provided.

[webcss]

QueryBuilder is intended to create an IDBKeyRange object. Simply call e.g.
var keyrange = queryBuilder.$gt(20).compile;
and use it in e.g. indexedDB.each(keyrange)

[marlonpp]

Can I use more than one index to construct a query?
var myQuery = $indexedDB.queryBuilder.$index('age_idx').$gt(40).$asc.$index('name_idx').$eq("test").compile;

Something like that.

[webcss]

No, you can only use one index per query, this is a limitation of indexedDB. As a workaround you can use your first index to limit a query, then open a cursor and test for secondary values to narrow your resultset.