A collegue of mine accidentally deleted the UserProfiles table from my database, which was generated from a model class.
Here's what the model class looks like:
namespace OneMillion.Models
{
[Table("UserProfile")]
public class User
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
public string UserName { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public string Sex { get; set; }
public string SecretQuestion { get; set; }
public string SecretQuestionAnswer { get; set; }
public int MoneyIn { get; set; }
public int MoneyOut { get; set; }
public int TimesWon { get; set; }
}
}
When I try to Update-Database via the package manager console I get this error:
Cannot find the object "dbo.UserProfile" because it does not exist or you do not have permissions.
Data migrations are enabled.
How can I solve this? Shall I delete the whole database?
Can you connect to the DB as a user with sufficient permissions to create databases? You could log in as that user in SSMS and create the table with the appropriate columns etc. Then the table exists, and migrations can find it.
Related
I'm quite new to .net and entity framework (this is my first project) and I'm getting the following error when trying to update the database:
*Introducing FOREIGN KEY constraint 'FK_Rating_User_UserId' on table 'Rating' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
Could not create constraint or index. See previous errors.*
I tried doing what it says (at least I think so) by adding the following to my dbContext class:
protected override void OnModelCreating(ModelBuilder modelbuilder)
{
modelbuilder.Entity<Rating>().HasOne(u => u.User).WithMany().OnDelete(DeleteBehavior.Restrict);
modelbuilder.Entity<Rating>().HasOne(g => g.Game).WithMany().OnDelete(DeleteBehavior.Restrict);
}
Not sure have I formulated that method correctly but it did not help (I tried with different DeleteBehavior like SetNull and NoAction)
The thing that really got me confused is that the issue appears even after removing all fields related to other tables from Rating class or even all references between all classes.
My Rating class:
public class Rating
{
public long RatingId { get; set; }
//[Rating]
public virtual Game Game { get; set; } // issue appears even after removing this and User line
//[Rating]
public int Score { get; set; }
public string CommentTitle { get; set; }
public string CommentDescription { get; set; }
//[Rating]
public virtual User User { get; set; }// issue appears even after removing this and Game line
}
User class:
public class User
{
public long UserId { get; set; }
//[Required]
public bool IsModerator { get; set; }
//[Required]
public string Username { get; set; }
//[Required]
public string Email { get; set; }
public string Name { get; set; }
public string Surname { get; set; }
//[Required]
public string Password { get; set; }
//[Required]
public string Salt { get; set; }
public string Description { get; set; }
}
Game class:
public class Game
{
public long GameId { get; set; }
//[Required]
public virtual User User { get; set; }
//[Required]
public string Title { get; set; }
public string Description { get; set; }
//[Required]
public string PricingType { get; set; }
public float MinDonation { get; set; }
public float MaxDonation { get; set; }
//[Required]
public string FileLocation { get; set; }
public float AverageRaiting { get; set; }
public int DownloadCount { get; set; }
}
GameImage class (probably unrelated to the issue just wanted to give a full context)
public class GameImage
{
public long GameImageId { get; set; }
//[Required]
public virtual Game Game { get; set; }
//[Required]
public string Location { get; set; }
//[Required]
public bool IsThumbnail { get; set; }
}
dbContext class:
public class dbContext : DbContext
{
public dbContext(DbContextOptions<dbContext> options) : base(options)
{
}
public DbSet<User> User { get; set; }
public DbSet<Rating> Rating { get; set; }
public DbSet<GameImage> GameImage { get; set; }
public DbSet<Game> Game { get; set; }
}
The issue only appeared after I tried to update the database. The first few migrations and updates were ok, however, then I tried adding [Required] annotation (you can see them commented in the above code) as I noticed that most of the fields were created as nullable in my database - after that the issue starting to occur even after removing the annotations.
In case that matters, I'm using Visual Studio 2019 and SQL Server Express
Does anyone have any idea what may be the cause of this?
Edit:
Image of of my database schema diagram from SSMS
As you can see in the database schema it's visible that there are indeed cycles in the database, however, I cannot get rid of them as Entity Framework's command "Update-Database" does not update the DB and just throws the error mentioned above.
Based on my test, you can try the following steps to solve the problem.
First, please change your dbcontext class into the following code.
public class dbContext : DbContext
{
public dbContext() : base("name=MyContext") { }
public DbSet<User> User { get; set; }
public DbSet<Rating> Rating { get; set; }
public DbSet<GameImage> GameImage { get; set; }
public DbSet<Game> Game { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
}
}
Second, please delete all the tables the database.
Third, please try the following command in your package console.
PM> Update-Database -Force
Finally, you can see the new tables in the databse.
I'm trying xamarin app... and I needed sqlite database... that contain 3 tables... users, accounts and transactions... the table of account seems:
[Table(nameof(Account))]
class Account
{
[PrimaryKey,AutoIncrement]
public int Id { get; set; }
public string Name { get; set; }
[ForeignKey(typeof(User))]
public int UserId { get; set; }
public double Balance { get; set; }
[ManyToOne]
public User User { get; set; }
[OneToMany(CascadeOperations = CascadeOperation.All)]
public List<Transaction> Transactions { get; set; }
}
I think there is no problem until here...
but in transaction table there are tow columns, FirstAccountId and TargetAccountId,so I like that:
[Table(nameof(Transaction))]
class Transaction
{
[PrimaryKey,AutoIncrement]
public int Id { get; set; }
[ForeignKey(typeof(Account))]
public int TargetAccountId { set; get; }
[ForeignKey(typeof(Account))]
public int FirstAccountId { get; set; }
public DateTime DateOfTransaction { get; set; }
[ManyToOne()]
public Account Account1 { get; set; }
[ManyToOne()]
public Account Account2 { get; set; }`
}
How I can make Account1 is the account for FirstAccountId and Account2 is the account for TargetAccountId
According to the source code of ManyToOne (see here), it takes an string foreignKey as a parameter. I did not find anything about it in the documentation, but I'd assume that you can specify an foreign key explicitly using this parameter, although I did not find anything about it in the documentation
[ManyToOne(nameof(FirstAccountId))]
public Account Account1 { get; set; }
[ManyToOne(nameof(TargetAccountId))]
public Account Account2 { get; set; }
I have got several models:
Course.cs
public class Course
{
public Guid Id { get; set; }
public ICollection<ApplicationUser> Teacher { get; set; }
public string Name { get; set; }
public string ShortName { get; set; }
public DateTime CreationDate { get; set; }
public bool IsActive { get; set; }
}
Group.cs
public class Group
{
public Guid Id { get; set; }
public ApplicationUser Mentor { get; set;}
public string DisplayName { get; set; }
public string GroupName { get; set; }
public DateTime StartYear { get; set; }
public string InviteCode { get; set; }
public ICollection<ApplicationUser> Students { get; set; }
public ICollection<Course> Courses { get; set; }
}
ApplicationUser.cs
public class ApplicationUser : IdentityUser
{
[Required]
public string Firstname { get; set; }
[Required]
public string Surname { get; set; }
public bool Gender { get; set; }
public DateTime Birthdate { get; set; }
//[Required]
public string InviteCode { get; set; }
public Guid GroupId { get; set; }
[ForeignKey("GroupId")]
public Group CurrentGroup { get; set; }
public ICollection<Group> PastGroups { get; set; }
}
Now when I try to register (using Identity) a user (not even trying to give the user a group) I receive this error:
SqlException: The INSERT statement conflicted with the FOREIGN KEY
constraint "FK_AspNetUsers_Groups_GroupId". The conflict occurred in
database "aspnet-Project_Dojo-3af15f80-8c62-40a6-9850-ee7a296d0726",
table "dbo.Groups", column 'Id'. The statement has been terminated.
In my modelBuilder I have added some logics for the relations between Group, ApplicationUser (Students) and the Foreign Key:
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
// Customize the ASP.NET Identity model and override the defaults if needed.
// For example, you can rename the ASP.NET Identity table names and more.
// Add your customizations after calling base.OnModelCreating(builder);\\
builder.Entity<ApplicationUser>()
.HasOne(p => p.CurrentGroup)
.WithMany(b => b.Students)
.HasForeignKey(p => p.GroupId);
}
I don't know what this is exactly doing, but I've been browsing some Stackoverflow threads to come to this code (migrations weren't working without it).
I look forward to a solution for my problem. Once again, I'm not doing ANYTHING with the groups yet when registering.
Thanks in advance!
not even trying to give the user a group
Well there's your problem, it's required.
Either provide a group, or make it optional by making the foreign key nullable (Guid? GroupId).
Because it's currently a non-nullable struct, it'll have a default value of all zeroes (Guid.Empty). This FK is not known in your database, resulting in the error you see.
I have 2 classes which have a many to many relation.
public class Document
{
public int Id { get; set; }
public string Name { get; set; }
public bool AvailableOffline { get; set; }
public string URL { get; set; }
public virtual ICollection<Profile> Profiles { get; set; }
}
public class Profile
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public virtual ICollection<Document> Documents { get; set; }
}
On each profile I wish to have a SortOrder field for each document. So I made the joined table explicit in another class
public class ProfileDocuments
{
[Key, Column(Order = 0)]
public int DocumentId { get; set; }
[Key, Column(Order = 1)]
public int ProfileId { get; set; }
public int SortOrder { get; set; }
[ForeignKey("DocumentId")]
public virtual Document Document { get; set; }
[ForeignKey("ProfileId")]
public virtual Profile Profile { get; set; }
}
But when I update the database the table for this last class will not have a column for SortOrder. It only holds the 2 foreign keys. How can I tell EF to generate this table with my column?
When a junction table in a many-to-many association should contain more information than just the two foreign keys, it's no longer possible to map the association as a 'pure' many-to-many (with hidden junction class).
You need an explicit class in the class model to address the extra information (as you already found out), but this also changes the association into 1-n-1:
class Document
{
...
public virtual ICollection<ProfileDocument> ProfileDocuments { get; set; }
}
class Profile
{
...
public virtual ICollection<ProfileDocument> ProfileDocuments { get; set; }
}
I have two model class, where I want to make one-to-one relation. When I make migration, I get an error:
The ALTER TABLE statement conflicted with the FOREIGN KEY constraint
"FK_dbo.Uzytkownik_dbo.UserProfile_UserId". The conflict occurred in
database "db_wydarzenia", table "dbo.UserProfile", column 'UserId'.
[Table("UserProfile")]
public class UserProfile
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
public string UserName { get; set; }
}
[Table("Uzytkownik")]
public class Uzytkownik
{
[Key]
public int UzytkownikID { get; set; }
public int UserId { get; set; }
public string Imie { get; set; }
public string Nazwisko { get; set; }
public string Telefon { get; set; }
public string Email { get; set; }
[ForeignKey("UserId")]
public UserProfile UserProfile { get; set; }
}
EDIT:
Problem solved :)
I remove all data from uzytkownik table and it's go.
If you want one-to-one - you cannot have both the primary-key and the foreign-key specified. One-to-one is modeled via primary-keys (pk == pk), otherwise it becomes 'multiplicity' (and just typical one-to-many).
To get what you want just remove your other PK - and user UserId as both primary and fk...
[Table("Uzytkownik")]
public class Uzytkownik
{
// [Key] public int UzytkownikID { get; set; }
[Key]
public int UserId { get; set; }
[ForeignKey("UserId")]
public UserProfile UserProfile { get; set; }
}