Teso_API/Teso API/AuthControllers/UsernameController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Teso_API.Models;

namespace Teso_API.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class UsernameController : ControllerBase
    {
        private readonly TESOContext _context;

        public UsernameController(TESOContext context)
        {
            _context = context;
        }

        // GET: api/Username/5
        [HttpGet("{id}")]
        public async Task<ActionResult> GetTesoUserDetail(string id)
        {
            if (!TesoUserDetailExists(id))
            {
                return Ok("Available");
            }
            else
            {
                return Conflict("Not Available");
            }
        }

        private bool TesoUserDetailExists(string id)
        {
            return _context.TesoUserDetails.Any(e => e.Username == id);
        }
    }
}