How to perform a lookup of a navigation property in EF Core 5 as part of a Create Dto

Question

I am new to [tag:Entity Framework] and having difficulties finding information on how to map [tag:navigation properties] in my Create Dto.

I have a JobCreateDto that needs to accept an AddressId and map from the Address database.

I have the following [tag:Fluent API] code but when I send a post request it asks for the other required properties for the address instead of just looking up the existing address by ID. It appears to be trying to create a new address.

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder
            .Entity<Job>()
            .HasOne(p => p.Address);
    }

Here is my HttpPost controller method:

    [HttpPost]
    public ActionResult<JobReadDto> CreateJob(JobCreateDto JobCreateDto)
    {
        var JobModel = _mapper.Map<Job>(JobCreateDto);

        _repository.CreateJob(JobModel);
        _repository.SaveChanges();

        var JobReadDto = _mapper.Map<JobReadDto>(JobModel);
   
        return CreatedAtRoute("GetJobById", new {Id = JobReadDto.Id}, JobReadDto);
    }

The Create Dto is quite long but here is the navigation property

     public virtual Address Address { get; set; }

Any help is appreciated. I remember doing this in a tutorial on Youtube but it was 8 hours into it and I'm not able to find it or a similar tutorial.

Thanks RyanS

I tried setting up the relationship using Fluent API in the OnModelCreating method of the DbContext but it appears to be trying to create a new address.

Edit to include Dto and Job class

JobCreateDto

    using System.ComponentModel.DataAnnotations;
    using TreffLandscapingDotNetApp.Models;
    
    namespace TreffLandscapingDotNetApp.Dtos
    {
        public class JobCreateDto
        {
    
    
            public DateTime DateOfWork { get; set; }
    
            public long Measure { get; set; }
    
            public DateTime StartTime { get; set; }
    
            public string StartLoc { get; set; }
    
            public DateTime EndTime { get; set; }
    
            public string EndLoc { get; set; }
    
            public double startLatitude { get; set; }
    
            public double startLongitude { get; set; }
    
            public double endLatitude { get; set; }
    
            public double endLongitude { get; set; }
    
            public Boolean wasSaltUsed { get; set; }
    
            public Boolean wasBinRefilled { get; set; }
    
            public double TotalTime { get; set; }
    
            public double Subtotal { get; set; }
    
            public double Tax { get; set; }
    
            public double Total { get; set; }
    
            public JobStatus Status { get; set; }
    
            public virtual Address Address { get; set; }
    
            public Agreement Agreement { get; set; }
    
            public int ServiceID { get; set; }
    
            public int ResourceID { get; set; }
        }
    }

Job class

using System.ComponentModel.DataAnnotations;

namespace TreffLandscapingDotNetApp.Models
{

public struct Coords
{
    public double x, y;

    public Coords(double p1, double p2)
    {
        x = p1;
        y = p2;
    }
}

    public enum JobStatus
    {
        New, 
        Scheduled, 
        Closed, 
        Completed
    }

    public class Job
    {
        [Key]
        [Required]
        public int Id { get; set; }

        public DateTime DateOfWork { get; set; }

        public long Measure { get; set; }

        public DateTime StartTime { get; set; }

        public string StartLoc { get; set; }

        public double startLatitude { get; set; }

        public double startLongitude { get; set; }

        public DateTime EndTime { get; set; }

        public string EndLoc { get; set; }

        public double endLatitude { get; set; }

        public double endLongitude { get; set; }

        public Boolean wasSaltUsed { get; set; }

        public Boolean wasBinRefilled { get; set; }

        public double TotalTime { get; set; }

        public double Subtotal { get; set; }

        public double Tax { get; set; }

        public double Total { get; set; }

        public JobStatus Status { get; set; }

        public virtual Address Address { get; set; }

        public Agreement Agreement { get; set; }

        public int ServiceID { get; set; }

        public int ResourceID { get; set; }

    }
}