Failure creating a migration with MSSQL: `Introducing FOREIGN KEY constraint '...' on table '...' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.`

Bug description

I attempted to use Prisma Migrate (2.17.0) to create a migration from the Prisma schema below and got the following error:

Error: Database error: Error querying the database: 'Introducing FOREIGN KEY constraint 'FK__Comment__postId' on table 'Comment' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.' on server 46f430d4d1fc executing  on line 57 (code: 1785, state: 0, class: 16)
   0: migration_core::api::ApplyMigrations
             at migration-engine/core/src/api.rs:51

It seems that the combination of defaulting to cascading deletes and a circular relation (between User : Post : Comment : User) causes the SQL to be invalid.

How to reproduce

1. Create the Prisma schema
2. Run npx prisma migrate dev --preview-feature to generate and apply the migration

This is where the error shows up.

I was able to resolve this by updating the FK__Comment__postId constraint in the migration SQ.

-- CreateTable
CREATE TABLE [dbo].[User] (
    [id] INT NOT NULL IDENTITY(1,1),
    [createdAt] DATETIME2 NOT NULL CONSTRAINT [DF__User__createdAt] DEFAULT CURRENT_TIMESTAMP,
    [email] NVARCHAR(1000) NOT NULL,
    [name] NVARCHAR(1000),
    CONSTRAINT [PK__User__id] PRIMARY KEY ([id]),
    CONSTRAINT [User_email_unique] UNIQUE ([email])
);

-- CreateTable
CREATE TABLE [dbo].[Post] (
    [id] INT NOT NULL IDENTITY(1,1),
    [createdAt] DATETIME2 NOT NULL CONSTRAINT [DF__Post__createdAt] DEFAULT CURRENT_TIMESTAMP,
    [title] NVARCHAR(1000) NOT NULL,
    [content] NVARCHAR(1000),
    [published] BIT NOT NULL CONSTRAINT [DF__Post__published] DEFAULT 0,
    [authorId] INT NOT NULL,
    CONSTRAINT [PK__Post__id] PRIMARY KEY ([id])
);

-- CreateTable
CREATE TABLE [dbo].[Comment] (
    [id] INT NOT NULL IDENTITY(1,1),
    [createdAt] DATETIME2 NOT NULL CONSTRAINT [DF__Comment__createdAt] DEFAULT CURRENT_TIMESTAMP,
    [comment] NVARCHAR(1000) NOT NULL,
    [writtenById] INT NOT NULL,
    [postId] INT NOT NULL,
    CONSTRAINT [PK__Comment__id] PRIMARY KEY ([id])
);

-- CreateTable
CREATE TABLE [dbo].[Tag] (
    [id] INT NOT NULL IDENTITY(1,1),
    [tag] NVARCHAR(1000) NOT NULL,
    CONSTRAINT [PK__Tag__id] PRIMARY KEY ([id]),
    CONSTRAINT [Tag_tag_unique] UNIQUE ([tag])
);

-- CreateTable
CREATE TABLE [dbo].[_TagToPost] (
    [A] INT NOT NULL,
    [B] INT NOT NULL,
    CONSTRAINT [_TagToPost_AB_unique] UNIQUE ([A],[B])
);

-- CreateIndex
CREATE INDEX [_TagToPost_B_index] ON [dbo].[_TagToPost]([B]);

-- AddForeignKey
ALTER TABLE [dbo].[Post] ADD CONSTRAINT [FK__Post__authorId] FOREIGN KEY ([authorId]) REFERENCES [dbo].[User]([id]) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE [dbo].[Comment] ADD CONSTRAINT [FK__Comment__writtenById] FOREIGN KEY ([writtenById]) REFERENCES [dbo].[User]([id]) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
-- I changed this one from "ON DELETE CASCADE ON UPDATE CASCADE" to "ON DELETE NO ACTION ON UPDATE NO ACTION" which resolved it
ALTER TABLE [dbo].[Comment] ADD CONSTRAINT [FK__Comment__postId] FOREIGN KEY ([postId]) REFERENCES [dbo].[Post]([id]) ON DELETE NO ACTION ON UPDATE NO ACTION;

-- AddForeignKey
ALTER TABLE [dbo].[_TagToPost] ADD CONSTRAINT [FK___TagToPost__A] FOREIGN KEY ([A]) REFERENCES [dbo].[Post]([id]) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE [dbo].[_TagToPost] ADD CONSTRAINT [FK___TagToPost__B] FOREIGN KEY ([B]) REFERENCES [dbo].[Tag]([id]) ON DELETE CASCADE ON UPDATE CASCADE;

Expected behavior

It should generate an executable migration.

Prisma information

Prisma schema:

generator client {
  provider        = "prisma-client-js"
  previewFeatures = ["microsoftSqlServer"]
}

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

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

model Post {
  id        Int       @id @default(autoincrement())
  createdAt DateTime  @default(now())
  title     String
  content   String?
  published Boolean   @default(false)
  authorId  Int
  author    User      @relation(fields: [authorId], references: [id])
  comments  Comment[]
  tags      Tag[]     @relation("TagToPost")
}

model Comment {
  id          Int      @id @default(autoincrement())
  createdAt   DateTime @default(now())
  comment     String
  writtenById Int
  postId      Int
  writtenBy   User     @relation(fields: [writtenById], references: [id])
  post        Post     @relation(fields: [postId], references: [id])
}

model Tag {
  id    Int    @id @default(autoincrement())
  tag   String @unique
  posts Post[] @relation("TagToPost")
}

Environment & setup

• OS: Mac OS
• Database: Microsoft SQL Server (Docker image: mcr.microsoft.com/mssql/server:2019-latest)
• Node.js version: v14.15.0
• Prisma version:

➜  sql-server git:(latest) npx prisma version
Environment variables loaded from prisma/.env
prisma               : 2.17.0
@prisma/client       : 2.17.0
Current platform     : darwin
Query Engine         : query-engine 3c463ebd78b1d21d8fdacdd27899e280cf686223 (at node_modules/prisma/node_modules/@prisma/engines/query-engine-darwin)
Migration Engine     : migration-engine-cli 3c463ebd78b1d21d8fdacdd27899e280cf686223 (at node_modules/prisma/node_modules/@prisma/engines/migration-engine-darwin)
Introspection Engine : introspection-core 3c463ebd78b1d21d8fdacdd27899e280cf686223 (at node_modules/prisma/node_modules/@prisma/engines/introspection-engine-darwin)
Format Binary        : prisma-fmt 3c463ebd78b1d21d8fdacdd27899e280cf686223 (at node_modules/prisma/node_modules/@prisma/engines/prisma-fmt-darwin)
Studio               : 0.353.0
Preview Features     : microsoftSqlServer

[janpio]

We are doing it the right way and will add detection of cyclic referential actions via: https://github.com/prisma/prisma/issues/4580 This will be added while SQL Server is still in preview.

The question if we wrap migrations in transactions is handled separately: https://github.com/prisma/prisma/issues/7641

[pantharshit00]

This still reproducible in 2.21.0-dev.38