"set" does not replace relations in update

Bug description

Following the doc: https://www.prisma.io/docs/reference/api-reference/prisma-client-reference/#set I could not use the set query as intended, the request is passing with no error but the relations are not created in database.

How to reproduce

Expected behavior

The items passed to the set query should update the items in database.

Prisma information

My models:

model Prospecting {
  id          Int                  @id @default(autoincrement())
  createdAt   DateTime             @default(now())
  modifiedAt  DateTime             @default(now())
  transaction String
  type        String
  minPrice    Int?
  maxPrice    Int?
  equipped    Boolean?
  furnished   Boolean?
  bedrooms    Int?
  archivedAt  DateTime?
  cities      ProspectingAndCity[] @relation("ProspectingTo_ProspectingAndCity")
}

model ProspectingAndCity {
  prospectingId Int
  cityId        Int
  City          City        @relation("CityTo_ProspectingAndCity", fields: [cityId], references: [id])
  Prospecting   Prospecting @relation("ProspectingTo_ProspectingAndCity", fields: [prospectingId], references: [id])

  @@id([prospectingId, cityId])
  @@map("_ProspectingAndCity")
}

model City {
  id                 Int                  @id @default(autoincrement())
  name               String
  linkedTo           String?
  ProspectingAndCity ProspectingAndCity[] @relation("CityTo_ProspectingAndCity")
}

The update query:

await prisma.prospecting.update({
  where: { id: 2 },
  data: {
    'transaction': 'L',
    'type': 'M',
    'minPrice': null,
    'maxPrice': null,
    'equipped': null,
    'furnished': null,
    'bedrooms': null,
    'archivedAt': null,
    'cities': {
      'set': [
        {
          'prospectingId_cityId': {
            'prospectingId': 5,
            'cityId': 54,
          },
        },
        {
          'prospectingId_cityId': {
            'prospectingId': 5,
            'cityId': 10,
          },
        },
      ],
    },
  },
});

Environment & setup

• OS: KDE neon User Edition 5.20 x86_64
• Database: PostgreSQL 12.5 (Debian 12.5-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
• Node.js version: v15.8.0
• Prisma version:

2.16.0

[jalik]

@richardwardza see my workaround above : https://github.com/prisma/prisma/issues/5456#issuecomment-772994699 Maybe we could ask for a new feature for that, like adding a replace instruction. Do you know if that would be possible/easy to implement ? @pantharshit00

await prisma.prospecting.update({
  where: { id: 2 },
  data: {
   ...attributes,
    'cities': {
      // this would remove any links between cities and this prospecting, and create new relations.
      'replace': [
        {
          'prospectingId_cityId': {
            'prospectingId': 5,
            'cityId': 54,
          },
        },
        {
          'prospectingId_cityId': {
            'prospectingId': 5,
            'cityId': 10,
          },
        },
      ],
    },
  },
});

[pantharshit00]

@jalik Sorry for the late reply here.

Sure go ahead with the feature request. I am going to close this one here.