如何使用Postgresql将值添加到2个表，然后将外键从一个表映射到Entity Framework Core中的另一个表？

Question

Here is another issue I have faced in ASP.NET Core Let say I have 2 Tables:

Accommodation
( ID, Name, LocationID)
Location
(ID, Address, Latitude, Longitude)

And I have a form:

Name:
Address:
Latitude:
Longitude:

Then when a button is clicked I want the value to be updated on both table and also MAP the LocationID to Accommodation table How should I code it in EF Core? Like a proper way

Answer 1

You could try the following example I made :

Accommodation Model and Location Model

 public class Accommodations
{
    public int ID { get; set; }
    public string Name { get; set; }
    public int LocationID { get; set; }
    [ForeignKey("LocationID")]
    public Location Location { get; set; }
}
public class Location
{
    public int ID { get; set; }
    public string Address { get; set; }
    //other stuff you want
}

DbSet two model in DbContext

 public class MVCDbContext:DbContext
{
    public MVCDbContext(DbContextOptions<MVCDbContext> options) : base(options)
    { }
    public DbSet<Accommodations> Accommodations { get; set; }
    public DbSet<Location> Location { get; set; }
}

The design of the view ,pay attention to the asp-for of the input tag

@model MVC2_1Test.Models.Accommodation.Accommodations
@{
ViewData["Title"] = "Accommondation";
}

<h2>Accommondation</h2>

<div class="row">
<div class="col-md-4">
    <form id="form" class=".has-error" asp-action="CreateAccommodation">
        <div asp-validation-summary="ModelOnly" class="text-danger"></div>
        <div class="form-group ">
            <label asp-for="Name" class="control-label"></label>
            <input asp-for="Name" class="form-control" id="cusName" />
            <span asp-validation-for="Name" class="text-danger"></span>
        </div>
        <div class="form-group">
            <label asp-for="Location.Address" class="control-label"></label>
            <input asp-for="Location.Address" class="form-control" id="age" />
            <span asp-validation-for="Location.Address" class="text-danger"></span>
        </div>
        <div class="form-group">
            <input type="submit" value="Create" class="btn btn-default" />

        </div>
    </form>
</div>
</div>

The action to update both table

[HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> CreateAccommodation([FromForm]Accommodations accommodation)
    {
        if (ModelState.IsValid)
        {
            _context.Add(accommodation);
            await _context.SaveChangesAsync();
            return RedirectToAction(nameof(Index));
        }
        return View(accommodation);
    }