breaking change on uuid column

Issue Description

update to 0.2.35, the uuid column force to char(36) #7853 , even if set type to varchar in options

Expected Behavior

if set type to varchar, it should be varchar

Actual Behavior

always char, no matter what type is set

export const IDColumnOpts = { type: 'varchar', charset: 'ascii', length: 36 } as const;

export abstract class BaseEntity extends TypeORMBaseEntity {
  @Generated('uuid')
  @PrimaryColumn({ comment: 'ID', ...IDColumnOpts })
  id: string;
}

Steps to Reproduce

// insert code here

My Environment

Dependency	Version
Operating System
Node.js version	x.y.zzz
Typescript version	x.y.zzz
TypeORM version	x.y.zzz

Additional Context

Relevant Database Driver(s)

DB Type	Reproducible
aurora-data-api	no
aurora-data-api-pg	no
better-sqlite3	no
cockroachdb	no
cordova	no
expo	no
mongodb	no
mysql	no
nativescript	no
oracle	no
postgres	no
react-native	no
sap	no
sqlite	no
sqlite-abstract	no
sqljs	no
sqlserver	no

Are you willing to resolve this issue by submitting a Pull Request?

• ✖️ Yes, I have the time, and I know how to start.
• ✖️ Yes, I have the time, but I don’t know how to start. I would need guidance.
• ✖️ No, I don’t have the time, but I can support (using donations) development.
• ✖️ No, I don’t have the time and I’m okay to wait for the community / maintainers to resolve this issue.

[maitrungduc1410]

I’m having same issue, after syncing, our production database columns get cleared because of this. Thanks for new release !

[ph1p]

Hi! My colleague @jsproede and I had the same problem and since we didn’t find any other solution, we wrote a migration. Maybe this helps one or the other.

The migration reads all your entities, finds their primary/foreign keys and modifies the column type. First we need to disable the foreign key checks, after everything has gone through we need to enable them again.

The good thing about this solution is that no data is lost!

Caution: Use at your own risk!

More: #8167 #7853 Docs: https://github.com/typeorm/typeorm/blob/master/docs/migrations.md

import { MigrationInterface, QueryRunner } from 'typeorm';
import { ColumnMetadata } from 'typeorm/metadata/ColumnMetadata';

export class UUIDMigration implements MigrationInterface {
  name = 'UUIDMigration';

  public async up(queryRunner: QueryRunner): Promise<void> {
    await this.runMigration(queryRunner, 'CHAR');
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await this.runMigration(queryRunner, 'VARCHAR');
  }

  private async runMigration(queryRunner: QueryRunner, type: 'VARCHAR' | 'CHAR') {
    await this.disableForeignKeyChecks(queryRunner);

    for (const { tableName, primaryColumns, foreignKeys } of queryRunner.connection.entityMetadatas) {
      for (const columnName of this.getRelevantPrimaryColumnNames(primaryColumns)) {
        await queryRunner.query(`ALTER TABLE ${tableName} MODIFY ${columnName} ${type}(36);`);
      }

      for (const foreignKey of foreignKeys) {
        for (const columnName of this.getRelevantForeignKeyColumnNames(foreignKey.columns)) {
          await queryRunner.query(`ALTER TABLE ${tableName} MODIFY ${columnName} ${type}(36);`);
        }
      }
    }

    await this.enableForeignKeyChecks(queryRunner);
  }

  private getRelevantForeignKeyColumnNames(foreignKeyColumns: ColumnMetadata[]) {
    return foreignKeyColumns.filter(column => column.type === 'uuid').map(column => column.databaseName);
  }

  private getRelevantPrimaryColumnNames(primaryColumns: ColumnMetadata[]) {
    return primaryColumns
      .filter(({ type, length }) => type === 'uuid' || (type === 'varchar' && length === '36'))
      .map(column => column.databaseName);
  }

  private async disableForeignKeyChecks(queryRunner: QueryRunner) {
    await queryRunner.query('SET foreign_key_checks = 0;');
  }

  private async enableForeignKeyChecks(queryRunner: QueryRunner) {
    await queryRunner.query('SET foreign_key_checks = 1;');
  }
}