Migration schema diffing fails with deleteRule: 'set null ("...")'

[Kalos-S]

Describe the bug

When generating migrations using the provided schema diffing breaks and the foreign key constraint on "parent_id" and "tenant_id" is recreated on every subsequent migration.

Reproduction

import {
  Entity,
  OneToOne,
  PrimaryKey,
  type Ref
} from "@mikro-orm/postgresql";

@Entity()
export class Parent {
  @PrimaryKey()
  id!: string;

  @PrimaryKey()
  tenant!: string;
}

@Entity()
export class Child {
  @PrimaryKey()
  id!: string;

  @PrimaryKey()
  tenant!: string;

  @OneToOne(() => Parent, { deleteRule: 'set null ("parent_id")', nullable: true })
  parent?: Ref<Parent> | null;
}

What driver are you using?

@mikro-orm/postgresql

MikroORM version

6.2.5

Node.js version

20.5.1

Operating system

No response

Validations

• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
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• The provided reproduction is a minimal reproducible example of the bug.

[B4nan]

Why do you put set null ("parent_id") into that? It should be only set null, or not?

[B4nan]

Oh right, it's for this thing I guess?

https://www.postgresql.org/message-id/CAF%2B2_SGRXQOtumethpuXhsyU%2B4AYzfKA5fhHCjCjH%2BjQ04WWjA%40mail.gmail.com

[Kalos-S]

That's a new feature of Postgres 16 (At the bottom of section 5.4.5 of their docs https://www.postgresql.org/docs/current/ddl-constraints.html#DDL-CONSTRAINTS-FK) which allows you to selectively apply the set null to the referencing columns