.Net SQL数据库无法识别模型变量

Question

I am working with a .Net API project. The trouble is, that I have a kind of slow computer and I was working with VS 2013 . After some time I installed VS 2015 , and it worked perfectly until I removed VS 2013 . Besides, the uninstallation of VS 2013 was pretty difficult, because I had to follow up this guide: Cannot uninstall, install or repair Visual Studio 2012 & 2013 (download whole setup, and use command line). Now problem is that now SQL server does not accept ManagerIds and WorkerIds that I pass. My document class:

 public class ConstructionSite
 {
    public int Id { get; set; }
    public int CreatorId { get; set; }
    public List<int> ManagerIds { get; set; }
    public List<int> WorkerIds { get; set; }
    public DateTime CreatedAt { get; set; }
    public bool IsActive { get; set; }
 }

But when I hit "Show table data" button, it only gives me this type of view:

I tried to change Configuration.cs class Seed method like this:

protected override void Seed(ReportRest.Models.ApplicationDbContext context)
{
    context.ConstructionSites.AddOrUpdate(new ConstructionSite
    {
        CreatorId = 2,
        CreatedAt = new DateTime(2000, 01, 01),
        IsActive = false,
        ManagerIds = new List<int> {1},
        WorkerIds = new List<int> {2},
    });
}

Then I removed existing Migrations folder, opened Nugget Package Manager Console and fired these commands: Enable-Migrations Add-Migration First Update-Database. Unfortunately, that hadn't helped me to recover ManagerIds and WorkerIds. So, before messing with unstable Microsoft setups, I would like to ask you if there is a way to remind my database of forgotten variables. Thanks in advance!

Answer 1

Not realy sure what columns your are missing, since all 4 normal columns are shown in database and the both lists should normaly be stored in own database-tables.

But if you use the default setup with ASP.net and EntityFramework and you already had a Migrations-folder, there should be also a "__MigrationHistory"-Table in database.

Means, if you deleted the old Migrationsfolder, your are also needed to delete the entries of the table. After that you can create an new "Add-Migration InitialCreate" and should get a whole first Migration of your current code base.

// For creating the new initial Datbase-Update to get a working migration for future changes:

1. Add the new Migration,
2. then cut the content of Up() and Down() Methode from new the migration file
3. Run Update-Database (to create the entry for __MigrationHistory-table)
4. Strg-Z in the migration-file to backup the original content
5. After that you are able to run Add-Migration and Update-Database for future changes of your Models

Answer 2

If you want one-to-may relations to Managers and Workers, you have to create something like this:

public class MyDbContext : DbContext
{
    public DbSet<ConstructionSite> ConstructionSites { get; set; }
    public DbSet<Manager> Managers { get; set; }
    public DbSet<Worker> Workers { get; set; }

    public MyDbContext()
        : base("YourConnectionStringName")
    {

    }
}

public class ConstructionSite
{
    public Guid Id { get; set; }
    public int CreatorId { get; set; }
    public List<Manager> Managers { get; set; }
    public List<Worker> Workers { get; set; }
    public DateTime CreatedAt { get; set; }
    public bool IsActive { get; set; }
}

public class Manager
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public Guid ConstructionSiteId { get; set; }
}

public class Worker
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public Guid ConstructionSiteId { get; set; }
}

This creates relations you want