zod-backend/src/db/migrations/1761032305682-AddUniqueConstraintToUserEmail.ts

import { MigrationInterface, QueryRunner } from "typeorm";

export class AddUniqueConstraintToUserEmail1761032305682 implements MigrationInterface {
    name = 'AddUniqueConstraintToUserEmail1761032305682'

    public async up(queryRunner: QueryRunner): Promise<void> {
        // Clean up duplicate emails - keep the oldest record (MIN id)
        await queryRunner.query(`
            DELETE FROM users
            WHERE id IN (
                SELECT u1.id
                FROM users u1
                INNER JOIN users u2 ON u1.email = u2.email AND u1.id > u2.id
                WHERE u1.email IS NOT NULL
            )
        `);
        
        // Add unique constraint
        await queryRunner.query(`ALTER TABLE "users" ADD CONSTRAINT "UQ_97672ac88f789774dd47f7c8be3" UNIQUE ("email")`);
    }

    public async down(queryRunner: QueryRunner): Promise<void> {
        await queryRunner.query(`ALTER TABLE "users" DROP CONSTRAINT "UQ_97672ac88f789774dd47f7c8be3"`);
    }

}