I get this error:
Introducing FOREIGN KEY constraint may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
What is the problem in my code?
public class AppUserMap : IEntityTypeConfiguration<AppUser>
{
public void Configure(EntityTypeBuilder<AppUser> builder)
{
builder.Property(m => m.Name).HasMaxLength(50).IsRequired(true);
builder.HasMany(m => m.Essays).WithOne(m => m.AppUser).HasForeignKey(m => m.AppUserId);
}
}
public class AppRoleMap : IEntityTypeConfiguration<AppRole>
{
public void Configure(EntityTypeBuilder<AppRole> builder)
{
builder.HasKey(m => m.Id);
builder.HasMany(m => m.AppUsers).WithOne(m => m.AppRole).HasForeignKey(m => m.AppRoleId).OnDelete(DeleteBehavior.NoAction);
}
}
public class AppRole : IdentityRole<int>, ITable
{
public List<AppUser> AppUsers { get; set; }
}
public class AppUser : IdentityUser<int>, ITable
{
public string Name { get; set; }
public string Picture { get; set; } = "default.png";
#nullable enable
public string? AppUserRole { get; set; }
#nullable disable
public bool Ban { get; set; } = false;
public List<Essay> Essays { get; set; }
public AppRole AppRole { get; set; }
public int AppRoleId { get; set; }
}
Thank you for answering. I solved the issue by changing a couple of things in my code.
This is my solution code(you can see the changes):
public class AppUser : IdentityUser<int>, ITable
{
public string Name { get; set; }
public string Picture { get; set; } = "default.png";
public bool Ban { get; set; } = false;
public List<Essay> Essays { get; set; }
#nullable enable
public AppRole? AppRole { get; set; }
public int? AppRoleId { get; set; }
#nullable disable
}
public class AppRoleMap : IEntityTypeConfiguration<AppRole>
{
public void Configure(EntityTypeBuilder<AppRole> builder)
{
builder.HasKey(m => m.Id);
builder.HasMany(m => m.AppUsers).WithOne(m => m.AppRole).HasForeignKey(m => m.AppRoleId).OnDelete(DeleteBehavior.SetNull);
}
}
Related
I've made a dotnet ef scaffold from database and the classes generated were:
public partial class Course
{
public int Id { get; set; }
public string? Description { get; set; }
}
public partial class Student
{
public int Id { get; set; }
public string? Name { get; set; }
}
public partial class StudentCourse
{
public int? IdStudent { get; set; }
public int? IdCourse { get; set; }
public virtual Student? IdStudentNavigation { get; set; }
public virtual Course? IdCourseNavigation { get; set; }
}
I want to get a List of Student where id of Course is X
I've tried _context.Student.Include("StudentCourse").Where(x=>x.Any(....) but Intellisense does not accept "Any" function.
How can i get this ?
Any(...) is a method provided by Enumerable class so you can not use it on a single Student (which is obviously not an Enumerable object).
Your configuration of many-to-many relationship is maybe missing some lines, here is my suggestion:
public partial class Course
{
public int Id { get; set; }
public string? Description { get; set; }
public List<StudentCourse> StudentCourses { get; set; }
}
public partial class Student
{
public int Id { get; set; }
public string? Name { get; set; }
public List<StudentCourse> StudentCourses { get; set; }
}
public partial class StudentCourse
{
public int? IdStudent { get; set; }
public int? IdCourse { get; set; }
public virtual Student? StudentNavigation { get; set; }
public virtual Course? CourseNavigation { get; set; }
}
In Context file:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<StudentCourse>()
.HasOne(sc => sc.StudentNavigation)
.WithMany(s => s.StudentCourses)
.HasForeignKey(sc => sc.IdStudent);
modelBuilder.Entity<StudentCourse>()
.HasOne(sc => sc.CourseNavigation)
.WithMany(c => c.StudentCourses)
.HasForeignKey(sc => sc.IdCourse);
}
Finally, your query could be:
IEnumerable<Student> students = await _context.Students
.Include(s => s.StudentCourses)
.Where(s => s.StudentCourses.Any(sc => sc.IdCourse == X)))
I am just taking your code as example but this is not a way you design entity in EF core.
Try following though.
var students
=_context.StudentCourse.Include("IdStudentNavigation").Where(x=>x.IdCourse == 1).Select(x => x.IdStudentNavigation).ToList();
Replace one with your course id.
This question already has an answer here:
Many to many relationship mapping in EF Core
(1 answer)
Closed 3 years ago.
Dotnet Core 2.2, EntityFrameworkCore 2.2.3
In a Many-to-Many relation between the entities "Post" and "Category" the linked Entity "PostCategory" returns the "Post" object but for the "Category" object only the Id and not the object itself.
Migrations and database update works fine and all three tables are created.
For the relation itself I tried it with EF "auto magic" and explicit definition of the relation in OnModelCreating in the ApplicationDbContext.
Models
Post-Model
public class Post
{
public int Id { get; set; }
public string Slug { get; set; }
public string Title { get; set; }
public string Abstract { get; set; }
public string Content { get; set; }
public string Author { get; set; }
public DateTime Created { get; set; }
public ICollection<PostCategory> PostCategories { get; set; }
}
Category-Model
public class Category
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public ICollection<PostCategory> PostCategories { get; set; }
}
PostCategory Model
public class PostCategory
{
public int PostId { get; set; }
public Post Post { get; set; }
public int CategoryId { get; set; }
public Category Category { get; set; }
}
DbSets in ApplicationDbContext
public DbSet<Post> BlogPosts { get; set; }
public DbSet<Category> BlogCategories { get; set; }
public DbSet<PostCategory> PostCategories { get; set; }
Get all Posts from Service
public IEnumerable<Post> GetAll()
{
var posts = _context.BlogPosts
.Include(x => x.PostCategories);
return posts;
}
Calling service from Controller
public IActionResult Index()
{
var blogPosts2 = _blogService.GetAll();
...
}
The result is seen in the screenshot.
In ApplicationDbContext I tried two versions:
Version 1:
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
builder.Entity<PostCategory>()
.HasKey(x => new { x.PostId, x.CategoryId });
}
public DbSet<Post> BlogPosts { get; set; }
public DbSet<Category> BlogCategories { get; set; }
public DbSet<PostCategory> PostCategories { get; set; }
Version 2:
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
builder.Entity<PostCategory>()
.HasKey(x => new { x.PostId, x.CategoryId });
builder.Entity<PostCategory>()
.HasOne(pt => pt.Post)
.WithMany(p => p.PostCategories)
.HasForeignKey(pt => pt.PostId);
builder.Entity<PostCategory>()
.HasOne(pt => pt.Category)
.WithMany(t => t.PostCategories)
.HasForeignKey(pt => pt.CategoryId); ;
}
public DbSet<Post> BlogPosts { get; set; }
public DbSet<Category> BlogCategories { get; set; }
public DbSet<PostCategory> PostCategories { get; set; }
Both version migrate and update with no errors and the same result.
I'm grateful for any help.
Best regards
Edit:
I tried the "ThenInclude" before but obviously my Visual Studio auto completion has a problem:
If I ignore the auto completion, then it works, thank you!
To eager load related data in multiple level, you have to use .ThenInclude as follows:
public IEnumerable<Post> GetAll()
{
var posts = _context.BlogPosts
.Include(x => x.PostCategories)
.ThenInclude(pc => pc.Category);
return posts;
}
Here is the more details: Loading Related Data: Including multiple levels
I'm trying to extend Application User (using Code-First) to hold a collection of orders, but I'm getting errors.
My Order class is
public class Order
{
public Order()
{
OrderDetails = new HashSet<OrderDetails>();
}
public int ID { get; set; }
public DateTime OrderDate { get; set; }
public string UserId { get; set; }
public bool IsDelivered { get; set; }
public bool IsReturned { get; set; }
public virtual ApplicationUser User { get; set; }
public virtual ICollection<OrderDetails> OrderDetails { get; set; }
}
And I'm trying to extend Application user like this
public class ApplicationUser : IdentityUser
{
public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
{
// Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
// Add custom user claims here
return userIdentity;
}
public string FirstName { get; set; }
public string LastName { get; set; }
public string CompanyName { get; set; }
public string Profession { get; set; }
public string TaxAuthority { get; set; }
public string TaxNumber { get; set; }
public string Address { get; set; }
public string PostalCode { get; set; }
public string City { get; set; }
public string Region { get; set; }
public string Country { get; set; }
public string Phone { get; set; }
public string MobilePhone { get; set; }
public bool NewsLetterSubscribe { get; set; } = false;
public DateTime TimeStamp { get; set; } = DateTime.Now;
public ICollection<Order> Orders { get; set; }
}
And I'm getting the following errors:
QCMS.Models.IdentityUserLogin: : EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType.
QCMS.Models.IdentityUserRole: : EntityType 'IdentityUserRole' has no key defined. Define the key for this EntityType.
IdentityUserLogins: EntityType: EntitySet 'IdentityUserLogins' is based on type 'IdentityUserLogin' that has no keys defined.
IdentityUserRoles: EntityType: EntitySet 'IdentityUserRoles' is based on type 'IdentityUserRole' that has no keys defined.
Can you please help me to solve this problem?
UPDATE:
I'm using two db contexts. The one provided for Individual User Account (when the project is first created) and a second one named "qvModel" that is for all other database classes of my project.
public partial class qvModel : DbContext
{
public qvModel()
: base("name=qvModel")
{
}
//APPSETTINGS
public virtual DbSet<AdminLog> AdminLog { get; set; }
public virtual DbSet<WebLog> WebLog { get; set; }
//LANGUAGES
public virtual DbSet<Language> Languages { get; set; }
.
.
.
public virtual DbSet<Order> Orders { get; set; }
public virtual DbSet<OrderDetails> OrderDetails { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
// Precision attribute for decimals
Precision.ConfigureModelBuilder(modelBuilder);
modelBuilder.Entity<Language>()
.HasMany(e => e.Brochures)
.WithRequired(e => e.Language)
.WillCascadeOnDelete(true);
.
.
.
modelBuilder.Entity<Order>()
.HasMany(c => c.OrderDetails)
.WithRequired(c => c.Order)
.WillCascadeOnDelete(true);
modelBuilder.Entity<ApplicationUser>()
.HasMany(c => c.Orders)
.WithRequired(c => c.User)
.WillCascadeOnDelete(true);
base.OnModelCreating(modelBuilder);
}
}
I found a solution that is very simple.
The solution is to inherit from IdentityDbContext like this
public class qvModel : IdentityDbContext<ApplicationUser>
{
public qvModel()
: base("name=qvModel")
{
}
I was also missing the following line from OnModelCreating
base.OnModelCreating(modelBuilder);
After these changes, my migration is working and I stopped getting the errors I mentioned.
I'm using the ASP Net Core 2.
I have a test model:
public class Player
{
public int Id { get; set; }
public string Name { get; set; }
public string Position { get; set; }
public int Age { get; set; }
[IgnoreDataMember]
public ICollection<PlayerTeam> PlayerTeams { get; set; }
public Player()
{
PlayerTeams = new List<PlayerTeam>();
}
}
public class PlayerTeam
{
public int PlayerId { get; set; }
public Player Player { get; set; }
public int TeamId { get; set; }
public Team Team { get; set; }
}
public class Team
{
public int Id { get; set; }
public string Name { get; set; } // название команды
// [IgnoreDataMember]
public ICollection<PlayerTeam> PlayerTeams { get; set; }
public Team()
{
PlayerTeams = new List<PlayerTeam>();
}
}
this is my DBcontext:
public class FootbollContext: DbContext
{
public DbSet<Player> Players { get; set; }
public DbSet<Team> Teams { get; set; }
public FootbollContext(DbContextOptions<FootbollContext> options)
: base(options)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<PlayerTeam>()
.HasKey(t => new { t.TeamId, t.PlayerId });
}
}
I have a query in my controller:
FootbollContext db;
var teams = db.Teams.Select(team => new {
TeamName = team.Name,
PlayersOlder20 = team.PlayerTeams.Where(pt => pt.Player.Age > 20).Select(s => s.Player)
});
and it works fine, but I want to use the Include()/ThenInclude() methods for this query, and I want to get the same equal results ie.
var teams = db.Teams.Include(p => p.PlayerTeams).ThenInclude(d => d.Player)
but I don't want to load all data! and I don't know how I can filter results by property "Players age (> 20)" in the relative table (not in the selectable!!) in one SQL Query.
How can I make many to many relation between AspNetRoles from Identity 3.0 and my custom table? I want simple 3 table, with both PermissionId and RoleId, something like AspNetUsersRole. I have something like this:
public class Permission
{
public int PermissionId { get; set; }
public string Name { get; set; }
public virtual ICollection<ApplicationRole> Roles { get; set; }
}
public class ApplicationRole : IdentityRole
{
public virtual ICollection<Permission> Permissions { get; set; }
}
But when I want to add migration, I got error:
Unable to determine the relationship represented by navigation property 'ApplicationRole.Permissions' of type 'ICollection<Permission>'. Either manually configure the relationship, or ignore this property from the model.
EF Core (EF7) does not currently support many to many relationship without a join entity. (Reference)
So, what you should do is to create an entity class for the join table and mapping two separate one-to-many relationships. Like;
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<PostTag>()
.HasKey(t => new { t.PostId, t.TagId });
modelBuilder.Entity<PostTag>()
.HasOne(pt => pt.Post)
.WithMany(p => p.PostTags)
.HasForeignKey(pt => pt.PostId);
modelBuilder.Entity<PostTag>()
.HasOne(pt => pt.Tag)
.WithMany(t => t.PostTags)
.HasForeignKey(pt => pt.TagId);
}
public class PostTag
{
public int PostId { get; set; }
public Post Post { get; set; }
public string TagId { get; set; }
public Tag Tag { get; set; }
}
Regarding to this question answer, it can be done more easily like this-
class Photo
{
public int Id { get; set; }
public ICollection<PersonPhoto> PersonPhotos{ get; set; }
}
class PersonPhoto
{
public int PhotoId { get; set; }
public Photo Photo { get; set; }
public int PersonId { get; set; }
public Person Person { get; set; }
}
class Person
{
public int Id { get; set; }
public ICollection<PersonPhoto> PersonPhotos{ get; set; }
}
Be sure to configure PersonPhoto with a composite key:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<PersonPhoto>().HasKey(x => new { x.PhotoId, x.PersonId });
}
To navigate, use a Select:
// person.Photos
var photos = person.PersonPhotos.Select(c => c.Photo);
Add This namespace-
using Microsoft.AspNetCore.Identity;
public class Permission
{
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int PermissionId { get; set; }
public string Name { get; set; }
public string UserIdFK { get; set; } //Foreign Key of Identity tbl
[ForeignKey("UserIdFK")]
public IdentityUser UserDetail { get; set; }
}
That's it, Happy coding :)