Find many returns empty array or null

Bug description

FindMany query returns null or empty, if it uses where in query with 1000+ items. This bug can be seen in many-to-many and one to many nested models. Tested in Mysql-8 and MariaDB. (EDIT: It works with PostgreSQL)

How to reproduce

Seed and then, these queries returns empty array;

this.prisma.user.findMany({ include: { posts: true }})
this.prisma.post.findMany({ include: { users: true }})
this.prisma.user.findMany({ where: { id: { lt: 51}}, include: { posts: true }});

But interestingly this works. (I think the problem is the count of where in ids, 50 * 20 = 1000)

this.prisma.user.findMany({ where: { id: { lt: 50}}, include: { posts: true }});

Expected behavior

[   {
        "id": 1,
        "email": "[e-mail]",
        "name": "9ev6v",
        "posts": []
    },
    {
        "id": 2,
        "email": "[e-mail]",
        "name": "y3nbu",
        "posts": []
    },
    {
        "id": 3,
        "email": "[e-mail]",
        "name": "oqjec",
        "posts": []
    }]

[   {
        "id": 1,
        "title": "p70a3",
        "content": "[e-mail]",
        "published": false,
        "users": []
    },
    {
        "id": 2,
        "title": "x3mg3",
        "content": "[e-mail]",
        "published": false,
        "users": []
    }]

Prisma information

generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "mysql"
  url      = env("DATABASE_URL")
}


model User {
  id    Int     @default(autoincrement()) @id
  email String  @unique
  name  String?
  posts Post[]
}

model Post {
  id        Int      @default(autoincrement()) @id
  title     String
  content   String?
  published Boolean? @default(false)
  users    User[]
}

Environment & setup

• OS: Ubuntu 22.04
• Database: MariaDB
• Node.js version: 16.15

Prisma Version

4.0.0

[jkomyno]

Closing this issue as it’s independent of Prisma: it’s instead related to a bug in some MariaDB versions. This reproduction runs test cases inspired by issue #14539 (which comprises #12338 and #14019 as well) on a “bugged” MariaDB instance (mariadb:10.7.3), on a “stable” MariaDB instance (mariadb:10.8.4), and on a recent MySQL instance (mysql:8.0.30).

Thanks to @kkomelin and @HendrikJan for their independent reproductions, and to @d-Rickyy-b for spotting https://jira.mariadb.org/browse/MDEV-27937.

[kkomelin]

@aqrln if you need a playground for that, please use my https://github.com/kkomelin/prisma-in-issue-reproduction and just change the docker image to the one you need to test with.