Remove primary key in entity framework table field in mvc4 - asp.net-mvc

Question

I have created a model in the name of Sample with an Id and DocumentId property.In this I don't mention primary key for Id property.But it forms the primary key when I created the Sample as table in entity framework.I want to remove the primary key for Id. What do I have to do. Please help me. I am very new to mvc4.
public class Sample
{
[Required,DatabaseGenerated(DatabaseGeneratedOption.None)]
public int Id { get; set; }
[Required]
public int DocumentId { get; set; }
}
public override void Up()
{
CreateTable(
"dbo.Samples",
c => new
{
Id = c.Int(nullable: false, identity: false),
DocumentId = c.Int(nullable: false),
})
.PrimaryKey(t => t.Id);
}

Answer 1

I am putting this here as I don't think it will show up very well in comments :)
In the case of a user having many roles (and each role possibly being played by many users), you would have three tables linked to 2 classes. The tables would be a Users table with a unique UserId column and the rest of the user details. Another table would be Roles with a unique RoleId and the rest of the role information and a joining table that would have the id of the user and the id of the role he plays (this table could have a unique id of itself). If the user has 2 roles, they would have 2 records in the joining table, one for each of the roles. The classes would look something like this:
public class User{
public long UserId {get;set;}
public ICollection<Role> roles{get;set;}
//Other properties of the user name, DOb,etc.
}
public class Role{
public long RoleId{get;set;}
public ICollection<User> Users{get;set;}
//other properties of Role
}
This is a many to many relationship. Of course you could also have it as a one to many relationship if the role can be played by one user. In that case you don't need the joining table and you can just add a UserId column to the Role table and instead of a collection of users, the role would have a single property of type user (not really needed unless you want to navigate back from role to user).

Answer 2

Try adding the NotMapped attribute in your Id.
public class Sample
{
[Key]
public int SampleId {get;set;}
[Required,DatabaseGenerated(DatabaseGeneratedOption.None)]
[NotMapped]
public int Id { get; set; }
[Required]
public int DocumentId { get; set; }
}
EDIT:
I added a key attribute to specify your primary key.
You can also try this, which I think is better:
public class Sample
{
public int SampleId {get;set;}
public virtual ICollection<Document> Documents {get;set;}
}
public class Document
{
public int DocumentId {get;set;}
public int SampleId {get;set;}
public virtual Sample Sample {get;set;}
}
virtual keyword is for lazy loading.

Answer 3

Open the entity diagram (.edmx) file and find which ever property in that particular table is the primary key. Right click on it and select "properties". In the properties window see where it says StoreGeneratedPattern - Identity? Change that to none and save the diagram. It will regenerate the .cs model files by itself

Answer 4

Fluent API suppresses the Data Annotations in Entity framework. Data Annotation for Primary is [Key] and ID is by default Primary key with identity.
In that scenario, Delete(if it's there) Data Annotation of ID i:e;[KEY] and use Fluent API in your context class. In below example, my primary key is "CustomerName" due to Fluent. Example:
public class Customer
{
public int CustomerName { get; set; }
public int ID { get; set; }
[Required]
public string ProductID { get; set; }
}
In Context Class:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Customer>().HasKey(s => s.CustomerName);
}