public class Graphic
{
...
...
[ScaffoldColumn(false)]
public int GraphicId { get; set; }
public virtual ICollection<GraphicArtwork> GraphicArtworks { get; set; }
}
public class GraphicArtwork
{
[Key]
public int GraphicArtworkId { get; set; }
public int GraphisId { get; set; }
[Required(ErrorMessage = "The {0} is required.")]
[StringLength(500)]
public string ArtOptionText { get; set; }
public decimal Price { get; set; }
[DisplayName("Active")]
public bool IsActive { get; set; }
public DateTime CreatedDate { get; set; }
[NotMapped]
public int TotalRecordCount { get; set; }
}
I have this two table and model. Here I have one Graphics with Many Art Work option. I have created my Artwork Option in view using Knockout.js. now my problem is that How to post(Action method) these data so that I can insert into GraphicArtwork table.
[HttpPost]
public ActionResult Add(Graphic data)
{
// "data" will contain all posted values
}
Related
Here are Entities:
public class Entity
{
public int Id { get; set; }
public DateTime CreatedOn { get; set; }
public DateTime? ModifiedOn { get; set; }
}
public class EntityBase : Entity
{
[ForeignKey("CreatedBy")]
public int CreatedById { get; set; }
public User CreatedBy { get; set; }
[ForeignKey("ModifiedBy")]
public int? ModifiedById { get; set; }
public User ModifiedBy { get; set; }
}
public class ProjectRequest : EntityBase
{
public string RequestTitle { get; set; }
public string RequestType { get; set; }
...
public virtual ICollection<Material> Materials { get; set; }
public virtual ICollection<Translation> Translations { get; set; }
}
public class Material : EntityBase
{
[ForeignKey("ProjectRequest")]
public int ProjectRequestId { get; set; }
public virtual ProjectRequest ProjectRequest { get; set; }
...
public virtual ICollection<Translation> Translations { get; set; }
}
public class Translation:EntityBase
{
[ForeignKey("ProjectRequest")]
public int ProjectRequestId { get; set; }
public virtual ProjectRequest ProjectRequest { get; set; }
[ForeignKey("Material")]
public int MaterialId { get; set; }
public virtual Material Material { get; set; }
public string ProductMasterText { get; set; }
[MaxLength(40)]
public string ShortDescription { get; set; }
public string MasterDescriptionLine1 { get; set; }
public string MasterDescriptionLine2 { get; set; }
public string MasterDescriptionLine3 { get; set; }
public string LanguageCode { get; set; }
}
No modifications has been done to these entities using fluent API.
Now, whenever I try to insert object of type ProjectRequest with Materials and Translations nested in it, in Translation objects ProjectRequestId is set to 0.
Following is sample Change Tracker snapshot:
Can anyone help me on this? Why ProjectRequestId is 0 but MaterialId properly assigned in Transaltion objects?
print("Hello World !");
I'm a beginner into the .NET world, i'm trying to use entity framework but i have a problem, my relations entities are not loaded, i followed the microsoft documentation but.
Here are my models :
[Table("Path")]
public class Path
{
[Key]
public int PathId { get; set; }
[Required]
public string Title { get; set; }
public List<Image> Images { get; set; }
[Required]
public string Description { get; set; }
[Required]
public float LocationX { get; set; }
[Required]
public float LocationY { get; set; }
[Required]
public string QrCode { get; set; }
public List<Mark> Marks { get; set; }
}
[Table("Mark")]
public class Mark
{
[Key]
public int MarkId { get; set; }
public int Value { get; set; }
public int PathForeignKey { get; set; }
[ForeignKey("PathForeignKey")]
public Path Path { get; set; }
}
[Table("Image")]
public class Image
{
[Key]
public int ImageId { get; set; }
[Required]
public string Name { get; set; }
public string Description { get; set; }
public int PathForeignKey { get; set; }
[ForeignKey("PathForeignKey")]
public Path Path { get; set; }
[Required]
public string Source { get; set; }
}
For me, everything is ok, i even have the correct entries into my database :
database entries
But my relation dont load when i'm reading database into my controller.
[HttpGet]
public IEnumerable<Path> GetAll()
{
return _context.Paths.ToList();
}
results
I'm sorry, i guess it is probably a stupid beginner error but i dont see what i did wrong. I tried with various database system, with virtual or not ...
Mark your navigation properties as virtual. For example:
[Table("Mark")]
public class Mark
{
[Key]
public int MarkId { get; set; }
public int Value { get; set; }
public int PathForeignKey { get; set; }
[ForeignKey("PathForeignKey")]
public virtual Path Path { get; set; } //Added virtual keyword
}
and a second way to load navigation properties is to use Include while fetching data:
return _context.Marks.Include(x => x.Path).ToList();
My EF Code First model for some reason is not in sync with the db. I'm getting this error:
{"Invalid column name 'Type_Id1'."}
The field is actually called 'Type_Id' so I'm not sure from where that 1 comes up. I have the table column called as Type_Id and also I've added a Type_Id in my type entity model.
Why might I be getting that error message, plus why I'm getting 1 at the end of the name?
Update
My Task class:
public class Task
{
public Task()
{
Language = 1;
Grades = new HashSet<Grade>();
Categories = new HashSet<Category>();
Subjects = new HashSet<Subject>();
Rooms = new Collection<Room>();
Tools = new Collection<Tool>();
}
[Key]
public int Id { get; set; }
public string Description { get; set; }
public virtual TaskType Type { get; set; }
public string Rules { get; set; }
[Required]
[StringLength(200), MinLength(1)]
public string Name { get; set; }
public int PreperationTime { get; set; }
public int InstructionTime { get; set; }
public int TaskTime { get; set; }
public int Type_Id { get; set; }
public string VideoLink { get; set; }
[Required]
public int Language { get; set; }
public int? MinimumParticipants { get; set; }
public int? MaximumParticipants { get; set; }
public int? Rating { get; set; }
[Required]
public string CreatedBy { get; set; }
public virtual ICollection<Grade> Grades { get; set; }
public virtual ICollection<Category> Categories { get; set; }
public virtual ICollection<Subject> Subjects { get; set; }
public virtual ICollection<Room> Rooms { get; set; }
public virtual ICollection<Tool> Tools { get; set; }
}
DBContext class:
public ApplicationDbContext() : base("DefaultConnection", false)
{
}
public DbSet<Task> Tasks { get; set; }
public DbSet<TaskType> TaskTypes { get; set; }
public static ApplicationDbContext Create()
{
return new ApplicationDbContext();
}
You need to add the FK attribute on your navigation property. EF is creating Type_Id1 because Type_Id already exists (although it can't tell by convention it is the FK).
[ForeignKey("Type_Id")]
public virtual TaskType Type { get; set; }
https://msdn.microsoft.com/en-us/data/jj591583.aspx#Relationships
I have a many to one relationship between Categories and News.
The problem I'm having is that EF keeps adding a foreign key colum to my table which I dont want!
News class
public class News
{
public News()
{
}
[Key]
public int NewsID { get; set; }
public int PublishedByID { get; set; }
public string PublishedByFullName { get; set; }
public string PublishedByEmail { get; set; }
public DateTime DatePublished { get; set; }
public string Title { get; set; }
public string PreviewText { get; set; }
public string BlobName { get; set; }
public virtual Category Category { get; set; }
}
Categories class
public class Category
{
public Category()
{
News = new HashSet<News>();
}
[Key]
public int CategoryID { get; set; }
public string Name { get; set; }
public string CategoryTypeName { get; set; }
public virtual ICollection<News> News { get; set; }
}
Database
My question
How do I remove Category_CategoryID in News table?
I'm guessing i'm missing some code in my OnModelCreating method.
You need to add id field in News class to reference Category.
public class News
{
[Key]
public int NewsID { get; set; }
public int CategoryID { get; set; } // added
public int PublishedByID { get; set; }
public string PublishedByFullName { get; set; }
public string PublishedByEmail { get; set; }
public DateTime DatePublished { get; set; }
public string Title { get; set; }
public string PreviewText { get; set; }
public string BlobName { get; set; }
public virtual Category Category { get; set; }
}
When creating many to many relationship using EF 4.3 code first approach, I cannot save data to connecting table, also cannot any examples on how to fill this table using saving object to Icollection... Here is my example:
MODELS
public class Hospital
{
//PK
[Key]
public int Id { get; set; }
public string Name { get; set; }
public string Address { get; set; }
public string City { get; set; }
public string County { get; set; }
public string UserName { get; set; }
public string Password { get; set; }
public Guid User_Id { get; set; }
//FK
public virtual ICollection<Operator> Operators { get; set; }
}
public class Operator
{
//PK
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime Dob { get; set; }
public string Email { get; set; }
//FK
public virtual ICollection<Hospital> Hospitals { get; set; }
}
public class Project: DbContext
{
public DbSet<Hospital> Hospitals { get; set; }
public DbSet<Operator> Operators { get; set; }
}
CONTROLLER
public void AddOperater()
{
Hospital h = new Hospital();
h = db.Hospitals.Single(a=>a.Id ==1);
var o = new Operator();
o.FirstName = "John";
o.LastName = "Doe";
o.Dob = new DateTime(1988,2,12);
o.Email = "johndoe#gmail.com";
o.Hospitals.Add(h);
db.SaveChanges();
}
With this approach I keep getting error here: o.Hospitals.Add(h); even when my Hospital instance is filled with data. How exactly to save data to both tables, the dbo.Operators and dbo.OperatorHospital which is relationship table?
o.Hospitals.Add(h) will fail because the list is a null list. You cannot call Add() on a null list. Typically most people get around this by instantiating the list in the constructor of the entity... like so... the current line is blowing up due to a CSharp issue.
public class Hospital
{
//PK
[Key]
public int Id { get; set; }
public string Name { get; set; }
public string Address { get; set; }
public string City { get; set; }
public string County { get; set; }
public string UserName { get; set; }
public string Password { get; set; }
public Guid User_Id { get; set; }
//FK
public virtual ICollection<Operator> Operators { get; set; }
public Hospital()
{
Operators = new List<Operator>();
}
}
public class Operator
{
//PK
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime Dob { get; set; }
public string Email { get; set; }
//FK
public virtual ICollection<Hospital> Hospitals { get; set; }
public Operator()
{
Hospitals = new List<Hospital>();
}
}