`count()` support distinct

Problem

I have bumped into a few cases where I need to do a ‘where’ filter and get records that are ‘distinct’, to add pagination I need to do a count query also with a ‘distinct’ option on ‘count()’, based on the documentation and experience, I can’t use distinct on a count()

export type FindManyUserArgs = {
  where?: UserWhereInput | null
  orderBy?: Enumerable<UserOrderByInput> | null
  skip?: number | null
  after?: UserWhereUniqueInput | null
  before?: UserWhereUniqueInput | null
  first?: number | null
  last?: number | null
}

Suggested solution

Can we update count() to support distinct as well? so it would accept the object similar to findMany()

export type FindManyUserArgs = {
  select?: UserSelect | null
  include?: UserInclude | null
  where?: UserWhereInput | null
  orderBy?: Enumerable<UserOrderByInput> | null
  cursor?: UserWhereUniqueInput | null
  take?: number | null
  skip?: number | null
  distinct?: Enumerable<UserDistinctFieldEnum>  
}

[chinanderm]

I would really love to see this feature added.

[kentcdodds]

For folks who need this, here’s my workaround until it’s supported:

 async function getReaderCount() {
   // couldn't figure out how to do this in one query without $queryRaw 🤷‍♂️
   type CountResult = [{count: number}]
   const [userIdCount, clientIdCount] = await Promise.all([
     prisma.$queryRaw`SELECT COUNT(DISTINCT "public"."PostRead"."userId") FROM "public"."PostRead" WHERE ("public"."PostRead"."userId") IS NOT NULL` as Promise<CountResult>,
     prisma.$queryRaw`SELECT COUNT(DISTINCT "public"."PostRead"."clientId") FROM "public"."PostRead" WHERE ("public"."PostRead"."clientId") IS NOT NULL` as Promise<CountResult>,
   ]).catch(() => [[{count: 0}], [{count: 0}]])
   return userIdCount[0].count + clientIdCount[0].count
 }