NestJS TypeORM createQueryBuilder SELECT query

I am trying ‘SELECT USER_CODE FROM USERS’ query by TypeORM in nestJS.
My databse is MySQL and this database has ‘users’ table.
the columns are ‘USER_CODE’, ‘USER_EMAIL’, ‘USER_PASSWORD’, ‘USER_PHONE’.
I’ve seen TypeORM official documents several times, but I don’t understand them well.

//service.ts
import { InjectRepository } from '@nestjs/typeorm';
import { Injectable } from '@nestjs/common';
import { Users } from './entity/users.entity';
import { Repository } from 'typeorm';
import { UsersSignupDto } from './dto/users.signup.dto';
import { generateCode } from 'src/common/utils/code.generator';

@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(Users) private userRepository: Repository<Users>,
  ) {}

  async signup(body: UsersSignupDto) {
    const user = await this.userRepository
      .createQueryBuilder()
      .select('users.user_code')
      .from(users,'users')
      .where('users.user_code = :id', { id: '74EQQK' })
      .getOne();
    console.log(user);
   
}

the code returns ‘null’ but I checked that table’s rows are not empty.

but when i tried

const user = await this.userRepository
      .createQueryBuilder()
      .where('users.user_code = :id', { id: '74EQQK' })
      .getOne();
      console.log(user);

It works.. but this qurey gets all informations from table.
I just want to get ‘user_code’ column. How to make it works? or Can someone link me the references information?