Reference
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db.isEmpty

Resolves to true if the table holds no rows. Returns a Promise, not a Query, so it does not batch.
Table.isEmpty() → Promise<boolean>

Resolves to true when the table holds no rows. Like db.every it returns a Promise rather than a Query, so keep it out of db.batch. Handy for a first-run seeding check.

Empty check
if (await Vendors.isEmpty()) {
  // seed defaults
}