queryIndexedDB

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A small query library for IndexedDB

Query construction

A query consists of the name of an index, an operation, and a comparison value. This is how you construct a query:

Index("make").oneof("BMW", "Volkswagen")

This will return all objects whose "make" index value is either "BMW" or "Volkswagen". Available operations are:

• eq
• lt, lteq
• gt, gteq
• between, betweeq
• oneof

It is possible to link queries with boolean operations, e.g.:

Index("make").eq("BMW") .and(Index("model").eq("325i")) .and(Index("year").lteq(1991))

Getting results

Getting results from a query works very much like getting results from a single index in IndexedDB. You have the option of a cursor, e.g.:

let cars = []; let store = transaction.objectStore("cars"); let request = query.openCursor(store); request.onsuccess = function (event) { let cursor = request.result; if (cursor) { cars.push(cursor.value); cursor.continue(); } }

or simply getting all values at once:

let cars; let request = query.getAll(store); request.onsuccess = function (event) { cars = request.result; }

query.openKeyCursor and query.getAllKeys are also available if just the keys are of interest.