Unable to return queried API data in ASP.NET from repository

Question

I am trying to return JSON data from an API. The API endpoint is "/api/getUserSchedule(int id)". It should return back JSON data where it has been filtered according to the staffId value, which is a foreign key to the taskSchedule table.

I can return all the data, as shown here using a different API endpoint

However, I need it to return data based on staffID. I have created an interface which is implemented by a repository.

interface code

public interface ITaskScheduleRepository
{    
  Task<TaskSchedule> GetUserSchedule(int id);  
}

Repository code

        public async Task<TaskSchedule> GetUserSchedule(int id)
    {
        var userTaskSchedule = await _context.TaskSchedules
        .Where(s => s.staffId == id)
        .ToListAsync();                                    

         return userTaskSchedule; // error is here            
    }

controller code

        [HttpGet("{id}")]
    public async Task<IActionResult> GetUserTaskSchedule(int id)
    {
        var taskUserSchedule = await _repo.GetUserSchedule(id);

        if(taskUserSchedule != null)
            return Ok(taskUserSchedule);            

        return BadRequest("There are no tasks for this user");     
    }

error message

Cannot implicitly convert type 'System.Collections.Generic.List' to 'Schedular.API.Models.TaskSchedule' [Schedular.API]csharp(CS0029)

Answer 1

You are trying to return a List<TaskSchedule> (note your .ToListAsync()) call in your repository method) but your interface is defined to return a single TaskSchedule. Update your interface and repository methods to return a List<TaskSchedule>

Task<IList<TaskSchedule>> GetUserSchedule(int id);

and

public async Task<IList<TaskSchedule>> GetUserSchedule(int id)

However, if a staff can only have one schedule, change your repository query to return a single item instead of a list of items.

var userTaskSchedule = await _context.TaskSchedules
    .Where(s => s.staffId == id)
    .FirstOrDefaultAsync();                                    

     return userTaskSchedule; /