Postgres primary key of type uuid: default value migration/sync not working

[joel31415]

Issue type:

[ ] question
[x] bug report
[ ] feature request
[ ] documentation issue

Database system/driver:
[x] postgres

TypeORM version:

[ ] latest
[ ] @next
[x] 0.2.24 (or put your version here)

Steps to reproduce or a small repository showing the problem:
When converting @PrimaryColumn('uuid') to @PrimaryGeneratedColumn('uuid') the migrations/synchronization does not actually update the default value to uuid_generate_v4(), it just drops and recreates all foreign keys. So it will never automatically sync/migrate completely.
Given these entities:

import {  Entity, PrimaryGeneratedColumn,  ManyToOne,  OneToMany,  JoinColumn,  PrimaryColumn } from 'typeorm'

@Entity()
export class User {
  @PrimaryColumn('uuid')
  // @PrimaryGeneratedColumn('uuid')
  id: string

  @OneToMany(() => Document, (doc) => doc.owner, { onDelete: 'CASCADE' })
  docs: Document[]
}

@Entity()
export class Document {
  @PrimaryColumn('uuid')
  id: string
  @ManyToOne(() => User, (user) => user.docs, { onDelete: 'CASCADE' })
  @JoinColumn({ name: 'ownerId' })
  owner
}

When swapping User's id to be @PrimaryGeneratedColumn('uuid') the resulting up migration looks like:

await queryRunner.query(`ALTER TABLE "document" DROP CONSTRAINT "FK_2d617266bd4cbb6ebcfdb5f67e2"`, undefined);
await queryRunner.query(`ALTER TABLE "document" ADD CONSTRAINT "FK_2d617266bd4cbb6ebcfdb5f67e2" FOREIGN KEY ("ownerId") REFERENCES "user"("id") ON DELETE CASCADE ON UPDATE NO ACTION`, undefined);

As you can see, it does not actually update the default value for the id column in the user table. It just recreates all foreign keys.

I believe there's another bug when going the other way too, the migration tries to remove a sequence that does not exist, the up migration looks like:

await queryRunner.query(`ALTER TABLE "document" DROP CONSTRAINT "FK_2d617266bd4cbb6ebcfdb5f67e2"`, undefined);
await queryRunner.query(`ALTER TABLE "user" ALTER COLUMN "id" DROP DEFAULT`, undefined);
await queryRunner.query(`DROP SEQUENCE "user_id_seq"`, undefined);
await queryRunner.query(`ALTER TABLE "document" ADD CONSTRAINT "FK_2d617266bd4cbb6ebcfdb5f67e2" FOREIGN KEY ("ownerId") REFERENCES "user"("id") ON DELETE CASCADE ON UPDATE NO ACTION`, undefined);

When using uuid there are no sequences. But when the sequence is removed from the migration, it does update the default value for the id column and future sync/migrations will be empty.

With this small case it's easy to see the issue, in my real-world case I'm migrating a code base to TypeORM and wanted to set a generated primary key uuid on an existing table.

Also, thanks for a great library!

[Hesowcharov]

I met the same problem - when switching from PrimaryKey('uuid') to PrimaryGeneratedColumn('uuid'), typeorm generates a migration which re-creates all foreign key constraints related with this table.

"typeorm": {
      "version": "0.2.25",
      ...

[OmgImAlexis]

PrimaryGeneratedColumn is working fine for me. I only got this issue when using PrimaryColumn with a custom default set.