I have the following scenario that is giving me a hard time:
public class SegUser
{
public string IdUser { get; set; }
public List<SegRol> SegRoles { get; set; }
public virtual List<SegApps> Apps{ get; set; }
}
public class SegRole
{
public virtual int IdRole { get; set; }
public virtual List<SegUer> SegUsers { get; set; }
public virtual List<SegApp> Apps { get; set; }
}
public class SegApp
{
public virtual int IdApp{ get; set; }
public virtual List<SegUser> Users { get; set; }
public virtual List<SegRole> Roles { get; set; }
}
In my database I have those 3 tables and an extra table with 3 PKs (one for each entity) to establish the relationship between those 3 entities.
How can I achieve the mapping with Entity Framework 5 fluent API.
I've already tried:
private void MapSegUser()
{
//mapping of another fields
entityConfiguration
.HasMany(x => x.SegRoles)
.WithMany(x => x.SegUsers)
.Map(mc =>
{
mc.MapLeftKey("id_role");
mc.MapRightKey("id_user");
mc.ToTable("seg_users_roles");
});
entityConfiguration
.HasMany(x => x.Apps)
.WithMany(x => x.Users)
.Map(mc =>
{
mc.MapLeftKey("id_app");
mc.MapRightKey("id_user");
mc.ToTable("seg_users_roles_apps");
});
}
private void MapSegApp()
{
//mapping of another fields
entityConfiguration
.HasMany(x => x.Users)
.WithMany(x => x.Apps)
.Map(mc =>
{
mc.MapLeftKey("id_user");
mc.MapRightKey("id_app");
mc.ToTable("seg_users_roles_apps");
});
}
private void MapSegRole()
{
//mapping of another fields
entityConfiguration
.HasMany(x => x.SegUsers)
.WithMany(x => x.SegRoles)
.Map(mc =>
{
mc.MapLeftKey("id_user");
mc.MapRightKey("id_role");
mc.ToTable("seg_users_roles");
});
}
Related
I created two tables named 'patient' and 'Admission'.For do that i created patient model and admission model classes.then i use HospitalDbContext class for creating tables using onModelCreating method. I want to use PatientId as a foreign-key of Admission table.But i can't find a way to add foreign key.Help me to solve this problem
Patient.cs :
public class Patient
{
public int PatientId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Nic { get; set; }
public int Age { get; set; }
public string Address { get; set; }
public string Email { get; set; }
public string Mobile { get; set; }
public DateTime RegisterDate { get; set; }
public string CurrentState { get; set; }
public string Password { get; set; }
}
Admission.cs :
public class Admission
{
public int AdmissionId { get; set; }
public int PatientId { get; set; }
public DateTime AdmissionDate { get; set; }
public string reason { get; set; }
}
HospitalDbContext.cs :
public class HospitalDbContext : DbContext
{
public HospitalDbContext(DbContextOptions<HospitalDbContext> options)
: base(options)
{
}
public DbSet<Patient> Patients { get; set; }
public DbSet<Admission> Admissions { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Patient>(entity =>
{
entity.HasKey(e => e.PatientId);
entity.Property(e => e.FirstName);
entity.Property(e => e.LastName);
entity.Property(e => e.Nic);
entity.Property(e => e.Age);
entity.Property(e => e.Address);
entity.Property(e => e.Email);
entity.Property(e => e.Mobile);
entity.Property(e => e.RegisterDate);
entity.Property(e => e.CurrentState);
entity.Property(e => e.Password);
});
modelBuilder.Entity<Admission>(entity=>
{
entity.HasKey(e => e.AdmissionId);
entity.Property(e => e.PatientId);
entity.Property(e => e.AdmissionDate);
entity.Property(e => e.reason);
});
}
public DbSet<patient_information_system_api.Models.Admission> Admission { get; set; }
}
As far as I know, we couldn't directly create the relationship without modifying the your Patient and Admission class.
If you want to achieve one to one relationship between the Admission and Patient, you should add Admission and Patient as property in each class and then use entity.HasOne(x=>x.Patient).WithOne(x=>x.Admission).HasForeignKey("PatientId"); to achieve your requirement.
More details, you could refer to below codes:
public class Patient
{
public int PatientId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Nic { get; set; }
public int Age { get; set; }
public string Address { get; set; }
public string Email { get; set; }
public string Mobile { get; set; }
public DateTime RegisterDate { get; set; }
public string CurrentState { get; set; }
public string Password { get; set; }
public Admission Admission { get; set; }
}
Admission:
public class Admission
{
public int AdmissionId { get; set; }
public int PatientId { get; set; }
public DateTime AdmissionDate { get; set; }
public string reason { get; set; }
public Patient Patient{ get; set; }
}
OnModelCreating:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Patient>(entity =>
{
entity.HasKey(e => e.PatientId);
entity.Property(e => e.FirstName);
entity.Property(e => e.LastName);
entity.Property(e => e.Nic);
entity.Property(e => e.Age);
entity.Property(e => e.Address);
entity.Property(e => e.Email);
entity.Property(e => e.Mobile);
entity.Property(e => e.RegisterDate);
entity.Property(e => e.CurrentState);
entity.Property(e => e.Password);
});
modelBuilder.Entity<Admission>(entity =>
{
entity.HasKey(e => e.AdmissionId);
entity.Property(e => e.PatientId);
entity.Property(e => e.AdmissionDate);
entity.Property(e => e.reason);
entity.HasOne(x=>x.Patient).WithOne(x=>x.Admission).HasForeignKey("PatientId");
});
}
You don't need to create foreign key there, just go to the Model that
you need to add foreign key on it and make a virtual from from the
model class that you need:
In your case, you can apply it like this:
public class Admission
{
public int AdmissionId { get; set; }
public int PatientId { get; set; }
[ScaffoldColumn(false)] //Add this to avoid create foreign key when scaffolding
public virtual Patient Patient {get; set;} //Add this to work as foreign key
public DateTime AdmissionDate { get; set; }
public string reason { get; set; }
}
After that when you need to read the foreign key, you can read it easily as follow:
//.Include used to read the foreign key
var _admission = await db.admission.Include(a => a.Patient).OrderBy(x => x.AdmissionDate);
And you can read more about foreign key and relationships from this link:
https://learn.microsoft.com/en-us/ef/core/modeling/relationships?tabs=fluent-api%2Cfluent-api-simple-key%2Csimple-key
In my project there is one to may relationship with two table(questions and asnwars). but when creating question no need to add answar but in my problem getting this error
Object reference not set to an instance of an object.
how can I solve this? is there any wrong thing in my code
this is the code what I tried.
public class QuestionDTO
{
[Key]
public int Id { get; set; }
public string Title { get; set; }
public string question { get; set; }
public int votes { get; set; }
public ApplicationUser starter { get; set; }
public virtual ICollection<VegCategoryDTO> tags { get; set; }
public ICollection<AnswerDTO> answers { get; set; }
}
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<QuestionDTO>().ToTable("tblQuestion");
modelBuilder.Entity<AnswerDTO>()
.HasRequired<QuestionDTO>(s => s.Question)
.WithMany(g => g.answers)
.HasForeignKey<int>(s => s.QuestionId)
.WillCascadeOnDelete();
}
}
public class QuestionController : ApiController
{
[AllowAnonymous]
public QuestionVM Post(QuestionVM model)
{
//if (!ModelState.IsValid)
//{
// return null;
//}
QuestionDTO dto = new QuestionDTO();
using (Db db = new Db())
{
dto.Id = model.Id;
dto.Title = model.Title;
dto.votes = model.votes;
dto.question = model.question;
ApplicationUser currentUser = (new ApplicationDbContext()).Users.FirstOrDefault(x => x.Id == userId);
dto.starter = currentUser;
dto.tags = model.tags;
dto.answers = model.answers;
db.Questions.Add(dto);
db.SaveChanges();
}
//_DbContext.SaveChanges();
return new QuestionVM(dto);
}
}
public class Db : DbContext
{
public DbSet<VegCategoryDTO> VegCategories { get; set; }
public DbSet<QuestionDTO> Questions { get; set; }
public DbSet<AnswerDTO> Answers { get; set; }
public DbSet<ApplicationUser> Users { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<QuestionDTO>()
.HasMany<VegCategoryDTO>(s => s.tags)
.WithMany(c => c.Questions)
.Map(cs =>
{
cs.MapLeftKey("QuestiontRefId");
cs.MapRightKey("VegCategoryRefId");
cs.ToTable("QuestiontVegCategory");
});
modelBuilder.Entity<AnswerDTO>()
.HasRequired<QuestionDTO>(s => s.Question)
.WithMany(g => g.answers)
.HasForeignKey<int>(s => s.QuestionId)
.WillCascadeOnDelete();
}
}
I been breaking my head for hours trying to find out why my navigation property is coming back null for 0 to many scenario. For 1 to 1 it works just fine.
These are my entities:
public class Barber: BaseEntity
{
public string Street1 { get; set; }
public string Street2 { get; set; }
public string City { get; set; }
public string State { get; set; }
public string PostalCode { get; set; }
public int? AppointmentId { get; set; }
public int? UserId { get; set; }
public virtual ICollection<Users> Users { get; set; }
public Barber()
{
}
}
public class Users: BaseEntity
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string Password { get; set; }
public string Email { get; set; }
public bool IsBarber { get; set; }
public int? BarberId { get; set; }
public string FacebookToken { get; set; }
public DateTime? CreatedOn { get; set;}
public virtual Barber Barber { get; set; }
/// <summary>
/// default constructor
/// </summary>
public Users() { }
}
my mapping is as follow:
for Barber:
public BarberMapping()
{
ToTable("Barber");
HasKey(p => p.Id);
Property(p => p.Street1).HasColumnName("Street1");
Property(p => p.Street2).HasColumnName("Street2");
Property(p => p.City).HasColumnName("City");
Property(p => p.State).HasColumnName("State");
Property(p => p.PostalCode).HasColumnName("PostalCode");
Property(p => p.AppointmentId).HasColumnName("AppointmentId");
Property(p => p.UserId).HasColumnName("UserId");
HasOptional(p => p.Users)
.WithMany()
.HasForeignKey(p => p.UserId);
}
}
for User:
public UserMapping()
{
ToTable("Users");
HasKey(p => p.Id);
Property(p => p.FirstName);
Property(p => p.LastName );
Property(p => p.Password);
Property(p => p.Email);
Property(p => p.CreatedOn);
Property(p => p.FacebookToken);
Property(p => p.IsBarber);
}
Finally i'm calling my data like this:
_userRepository.All.Where(p => p.Id == id).Include(p => p.Barber).FirstOrDefault();
When the query comes back I get everything except the Barber property which comes back as null. Anything i'm missing to make this relationShip work?
I'm using EF 6.1.3 with mySQL 6.9 on visual studio for mac.
I am using EF Core with MySQL using SapientGuardian's EFCore library and I am trying to create a table with many-to-many relationship using the following code;
public class Personnel
{
public int Id { get; set; }
[MaxLength(100)]
public string Name { get; set; }
public virtual ICollection<PersonnelDegree> PersonnelDegrees { get; set; }
}
public class Degree
{
public int Id { get; set; }
[MaxLength(100)]
public string Name { get; set; }
public virtual ICollection<PersonnelDegree> PersonnelDegrees { get; set; }
}
public class PersonnelDegree
{
public int PersonnelId { get; set; }
public int DegreeId { get; set; }
public virtual Personnel Personnel { get; set; }
public virtual Degree Degree { get; set; }
}
// Inside the OnModelCreating override
builder.Entity<Degree>().HasMany(x => x.Personnel);
builder.Entity<Personnel>().HasMany(x => x.Degrees);
builder.Entity<PersonnelDegree>()
.HasKey(x => new { x.DegreeId, x.PersonnelId });
builder.Entity<PersonnelDegree>()
.HasOne(x => x.Degree)
.WithMany(x => x.PersonnelDegrees)
.HasForeignKey(x => x.DegreeId);
builder.Entity<PersonnelDegree>()
.HasOne(x => x.Personnel)
.WithMany(x => x.PersonnelDegrees)
.HasForeignKey(x => x.PersonnelId);
Now, when I run dotnet ef migration add personnel; I get this...
migrationBuilder.CreateTable(
name: "Role",
columns: table => new
{
Id = table.Column<int>(nullable: false)
.Annotation("MySQL:AutoIncrement", true),
ApplicationId = table.Column<int>(nullable: true),
Name = table.Column<string>(maxLength: 100, nullable: true),
PersonnelId = table.Column<int>(nullable: true) // Where is this coming from?
},
constraints: table =>
{
table.PrimaryKey("PK_Role", x => x.Id);
table.ForeignKey(
name: "FK_Role_Application_ApplicationId",
column: x => x.ApplicationId,
principalTable: "Application",
principalColumn: "Id",
onDelete: ReferentialAction.Restrict);
});
Notice that the table definition has for Role has PersonnelId column in it. And Personnel table has RoleId? Can anybody tell me what is going on here?
I have the same models, but different OnModelCreating method.
So I assume that you configured something wrong. It should be something like this for your case:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<PersonnelDegree>()
.HasKey(t => new { t.PersonnelId , t.DegreeId });
}
That is all you should have in your OnModelCreating method.
I am using Entity Framework Code First with SQLCE in MVC3 for a blog-like site.
I am open to redesigning the structure if required, it would be great to get some help.
The context is set up as:
public class BinarContext : DbContext
{
public DbSet<Member> Members { get; set; }
public DbSet<Post> Posts { get; set; }
public DbSet<Reply> Replies { get; set; }
public BinarContext()
{
this.Configuration.LazyLoadingEnabled = true;
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Member>().HasMany(member => member.Posts)
.WithRequired(post => post.Member)
.HasForeignKey(post => post.MemberID)
.WillCascadeOnDelete();
modelBuilder.Entity<Member>().HasMany(member => member.Replies)
.WithRequired(reply => reply.Member)
.HasForeignKey(reply => reply.MemberID)
.WillCascadeOnDelete();
modelBuilder.Entity<Post>().HasMany(post => post.Replies)
.WithRequired(reply => reply.Post)
.HasForeignKey(reply => reply.PostID)
.WillCascadeOnDelete();
base.OnModelCreating(modelBuilder);
}
}
*Note: * I have tried getting rid of WillCascadeOnDelete(); as suggested by others on SO but hasn't worked so far.
The models are:
The Member class has information about the posts and replies made by the member.
public class Member
{
public Guid ID {get; set;}
public string Username { get; set; }
public string Email { get; set; }
public virtual ICollection<Post> Posts { get; set; }
public virtual ICollection<Reply> Replies { get; set; }
}
The Post class that has information about the member who posted it and for the replied posted for it.
public class Post
{
public Guid ID {get; set;}
[DataType(DataType.MultilineText)]
public string Text { get; set; }
public Guid MemberID { get; set; }
public virtual Member Member { get; set; }
public virtual ICollection<Reply> Replies { get; set; }
}
The Reply class that has information about the member who posted it and for the post it was posted.
public class Reply
{
public Guid ID { get; set; }
[DataType(DataType.MultilineText)]
public string Text { get; set; }
public Guid PostID { get; set; }
public Guid MemberID { get; set; }
public virtual Post Post { get; set; }
public virtual Member Member { get; set; }
}
Thanks for your help :)
Try this:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Member>().HasKey(x=>x.ID)
.HasMany(x => x.Posts)
.WillCascadeOnDelete();
modelBuilder.Entity<Member>().HasKey(x=>x.ID)
.HasMany(x => x.Replies)
.WillCascadeOnDelete();
modelBuilder.Entity<Post>().HasKey(x=>x.ID)
.HasMany(x => x.Replies)
.WillCascadeOnDelete();
modelBuilder.Entity<Post>().HasKey(x=>x.ID)
.WithRequired(x => x.Member)
.WithMany(x=>x.Posts);
modelBuilder.Entity<Replies>().HasKey(x=>x.ID)
.WithRequired(x => x.Member)
.WithMany(x=>x.Replies);
modelBuilder.Entity<Replies>().HasKey(x=>x.ID)
.WithRequired(x => x.Post)
.WithMany(x=>x.Replies);
base.OnModelCreating(modelBuilder);
}