liveQuery

Reactive queries that re-run when the data changes — including changes made in other tabs — and emit only when the result actually differs.

const sub = db.liveQuery(() => db.friends.where('age').above(30).toArray())
  .subscribe((rows) => render(rows));

sub.unsubscribe();

Behaviour

• Emits once immediately with the current result.
• Re-runs when a table the querier actually read changes. Tables are learned automatically on the first run; before that it listens to everything.
• Emits only when the result actually differs — a write that doesn't change your result produces no re-render.
• Errors go to the observer's error callback.

Options

db.liveQuery(querier, {
  tables: ['friends'],   // skip auto-detection and pin the dependency set
  debounceMs: 50,        // coalesce bursts
});

Framework interop — no adapter needed

The returned object is deliberately dual-shaped:

Framework	Usage
Svelte	$query directly — subscribe() returns an unsubscribe function, which is the Svelte store contract
Angular / RxJS	from(db.liveQuery(...)) — exposes Symbol.observable
React	import { useLiveQuery } from 'granth-react'
Vue	import { useLiveQuery } from 'granth-vue'
Vanilla	.subscribe(fn)

See Frameworks for full examples.

Manual change events

const off = db.onChange((tables) => console.log('changed:', tables));
off();