noob help : transaction not acid

 return await this.drizzle.db.transaction(async (trx) => {
      const u = await trx
        .select({
          usd: users.usd,
        })
        .from(users)
        .where(eq(users.id, 1));
      if (!u || u.length == 0) {
        throw new HttpException(
          {
            message: 'User not found',
            success: false,
          },
          404,
        );
      }

      const user = u[0];
      await this.timeout(5000);
      return (
        await trx
          .update(users)
          .set({
            usd: user.usd + val,
          })
          .where(eq(users.id, 1))
          .returning()
      )[0].usd;