What I'm trying to do
Automatically scaffold my Controller and Views based on my Model.
The Problem
My DropDownLists (a SelectedItemList) doesn't appear, instead I get a NumericUpDown element.
The Relation
A 'Bekroning' can have one 'Bekroner'.
A 'Bekroner' can 'bekroon' many 'Bekroningen'.
The Model
public class Bekroning
{
public int ID { get; set; }
[Required]
public int Omschrijving{ get; set; }
[Required]
public int Bekroner_ID { get; set; }
}
public class Bekroner
{
public int ID { get; set; }
[Required]
public string Naam { get; set; }
}
Similar Questions
MVC 5 Code First scaffolding with simple relationship
MvcScaffolding one-many relationship
But I can't get my head around it. Thanks in advance.
Related
I am working ASP.NET MVC using Entity frame work code first approach. I am facing an issue ,the issue is as i have dropped two tables by using Package Manager Console.
Now i am trying to add the tables, the tables are not getting added using Package Manager Console.
Getting Error Cannot find the object "dbo.Movies" because it does not exist or you do not have permissions.
Even in Indentity.cs Model [Movies] is mentioned.
public DbSet Movies { get; set; }
Below are the Model.
public class Movie
{
public int Id { get; set; }
public string Name { get; set; }
public DateTime ReleaseDate { get; set; }
public Genre Genres { get; set; }
public byte GenreId { get; set; }
public DateTime DateAdded { get; set; }
public int NumberOfStocks { get; set; }
}
public class Genre
{
public byte Id { get; set; }
public string Type { get; set; }
}
How to the add the new table in existing Entity frame work using Code first approach.
I have a simple ASPNET core Razor WEB App.
In this I have a the following Model classes
public class Student
{
public int ID { get; set; }
public string RegID { get; set; }
public string Name { get; set; }
public int? SectionID { get; set; }
public Section Section { get; set; }
}
public class Section
{
public int ID { get; set; }
public string Name { get; set; }
}
What I want to Create is a razor page where I can select a Section, and Select multiple students and Submit to Update All the selected students with the new selected sections.
Any kind of Help will be appreciated, Even ones with MVC solution.
Regards
I’m coming from an intermediate C++ background (and to a lesser extent, C#) and wanted to try to build a project in Asp.net MVC 6 with EF 7 – not realizing how completely different it is from simple C# forms. I’ve stumbled through and researched a lot but since I’m a total noob I’m stumped at this point.
I have the following models:
public class Shift
{
public int ShiftId { get; set; }
//other properties
public virtual ICollection<ShiftActivity> ShiftActivity { get; set;}
}
public class ShiftActivity
{
public int ShiftActivityID { get; set; }
public DateTime StartTime { get; set; }
public int ShiftID { get; set; }
public int ActivityID { get; set; }
public int LocationID { get; set; }
public virtual Shift Shift { get; set; }
public virtual Activity Activity { get; set; }
public virtual Location Location { get; set; }
}
public class Activity
{
public int ActivityID { get; set; }
public string ActivityName { get; set; }
public virtual ICollection<ShiftActivity> ShiftActivity { get; set; }
}
public class Location
{
public int LocationID { get; set; }
public string LocationName { get; set; }
public string LocationAddress { get; set; }
public int locationZip { get; set; }
public virtual ICollection<ShiftActivity> ShiftActivity { get; set; }
}
I would like to create a shift and be able to input all the required fields all from one view. For instance, when I create the shift, I need to pick the type of location and activity to add to the ShiftActivity table which is then updated. Eventually I would like to be able to dynamically add additional activities (I’m assuming I’ll need javascript for that), but that’s another issue. I know I need a viewmodel to access all the tables, but I’m unclear as to how the viewmodel should be structured correctly.
Also, can the ShiftController update the ShiftActivity table directly or do I need to transfer the data somehow to the ShiftAcitivityController when the form is submitted? Either way, can someone point me to an example? Thank you… Any help is greatly appreciated.
First of all ASP.NET and MVC 4 are very new to me (+- one month) and sorry if its a bad question.
I've got two classes "Turma" and "Curso"
public class Turma
{
[Key]
public int idCurso { get; set; }
public string RefTurma { get; set; }
public Curso Curso { get; set; }
public string NomeCurso { get; set; }
}
and
public class Curso
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int idArtigoAT { get; set; }
public string ConteudoPrograma { get; set; }
public virtual ICollection<Turma> Turmas { get; set; }
}
After this I started a migration and updated the database. So far so good, but then problems.
Due to new information the primary key type should be varchar(18). I've tried to change but so far without success.
Any ideia or solution???
No, what you want is an 'Id' property and an 'MyCustomUniqueName' property. this custom property, should be and unique index in database. this is the best design for this situation IMHO.
I want to have a list of stands (at a trade show) and a list of exhibitors.
The list of stands is separate to the list of exhibitors - however, once registered, I want the exhibitor to be able to book a stand.
When they select/book a stand - I would like to then be able to have a list the stands in my view, and also show the associated exhibitor who has booked it.
Likewise, I would like to list in another view, the exhibitors, and also which stand they have booked.
So I'm trying to setup a one to one relationship (using EF CodeFirst).
However, when trying to add a controller for either the Stand or the Exhibitor, I get the following error:
My models are:
public class Stand
{
public int StandID { get; set; }
public string Description { get; set; }
public bool Booked { get; set; }
public int ExhibitorID { get; set; }
public virtual Exhibitor Exhibitor { get; set; }
}
public class Exhibitor
{
public int ExhibitorID { get; set; }
public string Company { get; set; }
public int StandID { get; set; }
public virtual Stand Stand { get; set; }
}
I'm certain it's something to do with the "Virtual" part of the models.
Can anyone please help point out what should be updated, to allow the connection?
Thank you,
Mark
EF doesn't know which entity is the principal (parent) and which is the dependent (child). You need to declare a foreign key on the item that entity that should come first. You can do this with an annotation or a fluent mapping.
Annotation
Add the following namespace:
using System.ComponentModel.DataAnnotations.Schema;
Annotate your Stand class with the following annotation:
public class Stand
{
[ForeignKey("Exhibitor")]
public int StandID { get; set; }
public string Description { get; set; }
public bool Booked { get; set; }
public int ExhibitorID { get; set; }
public virtual Exhibitor Exhibitor { get; set; }
}
Fluent Mapping
Override your OnModelCreating method in your DbContext class to include:
modelBuilder.Entity<Stand>()
.HasOptional(s => s.Exhibitor)
.WithRequired(e => e.Stand);
The model you have created is not possible to work with relational databases. The Stand needs an ExibitorId while Exibitor need a StandId. The cyclic relationship does not allow you to insert any rows to either tables.
Assuming an Exibitor may have more than one Stand and converting the relationship to one-to-many is one option.
public class Stand
{
public int StandID { get; set; }
public string Description { get; set; }
public bool Booked { get; set; }
public int? ExhibitorID { get; set; }
public virtual Exhibitor Exhibitor { get; set; }
}
public class Exhibitor
{
public int ExhibitorID { get; set; }
public string Company { get; set; }
public virtual ICollection<Stand> Stands { get; set; }
}
Or you can use shared primary key mapping to make the relationship one-to-one. Where Stand is the principal entity. The Exibitor will use the StandID as its PK.
public class Stand
{
public int StandID { get; set; }
public string Description { get; set; }
public bool Booked { get; set; }
public virtual Exhibitor Exhibitor { get; set; }
}
public class Exhibitor
{
public int ExhibitorID { get; set; }
public string Company { get; set; }
public virtual Stand Stand { get; set; }
}
Using the Fluent API to configure the relationship.
modelBuilder.Entity<Exibitor>().HasRequired(e => e.Stand)
.WithOptional(s => s.Exibitor);