Available since 4.3.0.

enable in your schema file:

generator client {
  provider        = "prisma-client-js"
  previewFeatures = ["filteredRelationCount"] << add this 
}

and then query:

await prisma.post.findMany({
  select: {
    _count: {
      select: {
        comment: { where: { approved: true } },
      },
    },
  },
})

I figured out myself. This is a preview feature in prisma 2.30. To solve this, just upgrade both prisma and prisma/client version to 3.30 with

npm install prisma@3 @prisma/client@3 

Even though the count relations is added since prisma 2.21. But from there release note, this function is generally available in prisma 3.01. So, in 2.30, this function might not be available. To use it in prisma 2.30, the preview feature needs to be enabled.

Enabling a Prisma Client preview feature To enable a Prisma Client Preview feature:

Add the Preview feature flag to the generator block:

generator client { provider = "prisma-client-js"
previewFeatures = ["mongoDb"] } Re-generate the client:

npx prisma generate If you are using Visual Studio Code and the Preview feature is not available in your .ts file after generating the client, run the TypeScript: Restart TS server command.

Prisma 3.30 Release Notes

Select Relation Count is Generally Available Select Relation Count allows you to count the number of related records by passing _count to the select or include options and then specifying which relation counts should be included in the resulting objects via another select.

Select Relation Count helps you query counts on related models, for example, counting the number of posts per user:

const users = await prisma.user.findMany({ include: { _count: { select: { posts: true }, }, }, }) Expand to view the structure of the returned users If you've been using this Preview feature, you can remove the selectRelationCount flag from previewFeatures in your Prisma Schema.

See the upgrade reference here. See Prisma Release Notes here.

Hi @MorenoMdz 👋

Thank you for raising this question.

This is not possible at the moment. We do have an open feature request to allow searching by relation count. Do add a 👍 to the issue to enable our engineers prioritize it. You can also add your use case to the issue.

If this answers your question, it would be great if you could mark this Discussion as answered to indicate that it has been resolved.

Otherwise please let us know how else we can help you further or close the Discussion if it was resolved in some other way 🙏

Hey @jamalmoir 👋,

This is not currently possible with Prisma but sounds like a good idea for a feature request.

In the meantime, you can use $queryRaw to accomplish the same thing.

There's no direct way to do a condition like this in Prisma, but here is a workaround you could use:

1. Do a groupBy query for the filter condition.
2. Use a map to create array of User.id fields of all the user ids that match the filter condition.
3. Do the normal findMany query, but add an extra notIn condition with the array of filtered user ids.

Here is what the whole thing would look like:

const userId = 'testUser';

// step 1
const dataForFilter = await prisma.playMateRequest.groupBy({
    by: ['targetUserId'],
    where: {
        response: "reject",
        requestingUserId: userId
    },
    having: {
        targetUserId: {
            _count: {
                equals: 3  
            }
        }
    }
})

// step 2
let exclude_users = [userId]
exclude_users = exclude_users.concat(dataForFilter.map(item => item.targetUserId))

let result = await prisma.playMateRequest.user.findMany({
    where: {
        id: {
        notIn: exclude_users
        },
        lang: "en"
    }
    });

I might have misinterpreted the exact details of the query you want to achieve but I think this should give you the query structure in general. Tweak the groupBy query as necessary to match your exact condition.

This is the link to the issue