add postgres upsert
mutations to postgraphile
yarn add postgraphile-upsert
import { PgMutationUpsertPlugin } from 'postgraphile-upsert'
postgraphile(pgClient, 'yourSchema', {
appendPlugins: [PgMutationUpsertPlugin as any]
})
fire open PostGraphiQL
and look for mutation { upsert<ModelName> { ... } }