loop through the table/object store values and see if the current cursor column contains the keyword:

var keyword = "foo";
var transaction = db.transaction("table", "readwrite");
var objectStore = transaction.objectStore("table");
var request = objectStore.openCursor();
request.onsuccess = function(event) {
	var cursor = event.target.result;
	if (cursor) {
		if (cursor.value.column.indexOf(keyword) !== -1) {
			console.log("We found a row with value: " + JSON.stringify(cursor.value));
		}  
		cursor.continue();		  
	}
};


to INSERT or UPDATE records, use objectStore.put(object)
only want to INSERT records, use objectStore.add(object)

• localForage (~8KB, Promises, good legacy browser support)
• idb-keyval (<500 bytes, Promises, use if only need key-value support)
• idb (~1.7KB, Promises, also does iteration, indexing)
• Dexie (~16KB, Promises, complex queries, secondary indices)
• PouchDB (~45KB (supports custom builds ), synchronization)
• Lovefield (relational)
• LokiJS (in-memory)
• ydn-db (dexie-like, works with WebSQL)

Service Worker Libraries worth checking out

• sw-toolbox (offline caching for dynamic/runtime requests)
• sw-precache (offline precaching for static assets/application shells)
• Webpack users can directly use the above or offline-plugin