C#•9mo ago

✅ EF Core delete error

hi, i tried to fix it but nothing works, so i have dbcontext

public interface IApplicationDbContext
{
    DbSet<Chat> Chats { get; set; }
    DbSet<Message> Messages { get; set; }
    DbSet<Connection> LiveConnections { get; set; }
    int SaveChanges();
    Task<int> SaveChangesAsync(CancellationToken cancellationToken = default);
}

public interface IApplicationDbContext
{
    DbSet<Chat> Chats { get; set; }
    DbSet<Message> Messages { get; set; }
    DbSet<Connection> LiveConnections { get; set; }
    int SaveChanges();
    Task<int> SaveChangesAsync(CancellationToken cancellationToken = default);
}

public class ApplicationDbContext : DbContext, IApplicationDbContext
{
    public DbSet<Chat> Chats { get; set; } = null!;
    public DbSet<Message> Messages { get; set; } = null!;
    public DbSet<Connection> LiveConnections { get; set; } = null!;

    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
        : base(options)
    {
        Database.EnsureCreated();
    }

    public override int SaveChanges()
    {
        return base.SaveChanges();
    }

    public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
    {
        return await base.SaveChangesAsync(cancellationToken);
    }
}

public class ApplicationDbContext : DbContext, IApplicationDbContext
{
    public DbSet<Chat> Chats { get; set; } = null!;
    public DbSet<Message> Messages { get; set; } = null!;
    public DbSet<Connection> LiveConnections { get; set; } = null!;

    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
        : base(options)
    {
        Database.EnsureCreated();
    }

    public override int SaveChanges()
    {
        return base.SaveChanges();
    }

    public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
    {
        return await base.SaveChangesAsync(cancellationToken);
    }
}

and

public class Chat
{
    [Key]
    public int Id { get; set; }
    public int? AuthorId { get; set; } = null!;
    public string Title { get; set; } = null!;
    public List<Connection>? LiveConnections { get; set; }
    public List<Message>? Messages { get; set; }
}

public class Chat
{
    [Key]
    public int Id { get; set; }
    public int? AuthorId { get; set; } = null!;
    public string Title { get; set; } = null!;
    public List<Connection>? LiveConnections { get; set; }
    public List<Message>? Messages { get; set; }
}

public class Connection
{
    [Key]
    public int? Id { get; set; }
    public string ConnectionId { get; set; } = "Undefined";
    public int? ChatId { get; set; }
    public int? UserId { get; set; }
}

public class Connection
{
    [Key]
    public int? Id { get; set; }
    public string ConnectionId { get; set; } = "Undefined";
    public int? ChatId { get; set; }
    public int? UserId { get; set; }
}

public class Message
{
    [Key]
    public int? Id { get; set; }
    public int? ChatId { get; set; } = null!;
    public int? SenderId { get; set; } = null!;
    public DateTime? Date { get; set; } = DateTime.Now;
    public string? Content { get; set; }
}

public class Message
{
    [Key]
    public int? Id { get; set; }
    public int? ChatId { get; set; } = null!;
    public int? SenderId { get; set; } = null!;
    public DateTime? Date { get; set; } = DateTime.Now;
    public string? Content { get; set; }
}

so, error only happens when chat have Include (connections / messages). how to make on delete chat don't care about this things?

9 Replies

jcotton42•9mo ago

what error? and show the code that's causing the error

wwww•9mo ago

1 sec, windows update

wwww•9mo ago

so, error happens when i call this action

[HttpDelete]
public async Task<IActionResult> DeleteChat([FromBody] DeleteChatDTO helper)
{
    Chat? chat = await _db.Chats.FirstOrDefaultAsync(chat => chat.Id == helper.ChatId);

    if (chat == null)
        return NotFound("Chat with this Id not found");

    if (chat.AuthorId != helper.SenderId)
        return BadRequest("this user doesn't have permissions");

    _db.Chats.Remove(chat);
    await _db.SaveChangesAsync();

    return Ok("Chat successfully deleted");
}

[HttpDelete]
public async Task<IActionResult> DeleteChat([FromBody] DeleteChatDTO helper)
{
    Chat? chat = await _db.Chats.FirstOrDefaultAsync(chat => chat.Id == helper.ChatId);

    if (chat == null)
        return NotFound("Chat with this Id not found");

    if (chat.AuthorId != helper.SenderId)
        return BadRequest("this user doesn't have permissions");

    _db.Chats.Remove(chat);
    await _db.SaveChangesAsync();

    return Ok("Chat successfully deleted");
}

jcotton42•9mo ago

how is your OnDelete set up? LiveConnections.ChatId would be referring to a Chat that no longer exists so you either need to manually remove that connection yourself, or set up Cascade or SetNull as the deletion action

wwww•9mo ago

i gues OnDelete don't exists in my code, atleast i don't wrote it so, when i was googling problem, they sain i need to set up cascade delete but I haven't figured it out how 😦

jcotton42•9mo ago

also, that EnsureCreated in your db context constructor is gonna bite you EnsureCreated is not compatible with migraitons

wwww•9mo ago

so, i just need to figure out how to cascade delete? for that thing work

jcotton42•9mo ago

yeah

wwww•9mo ago

ok thanks a lot

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✅ EF Core delete error