Code First EF relationship duplicate - c#

I have a working model, but have noticed that the relationship has been created twice in the database. Originally, it created two columns in the table, but with the addition of a specified foreign key attribute it has now just the one.
I have an Account class, which has many employers who can use the account. (one to many) Here are the classes:
public class Account
{
public int AccountId { get; set; }
[Required(ErrorMessage = Constants.ValidationMessages.FieldRequired)]
public string Name { get; set; }
public int? PrimaryUserId { get; set; }
[ForeignKey("PrimaryUserId")]
public Employer PrimaryUser { get; set; }
[ForeignKey("EmpAccountId")]
public ICollection<Employer> Employers { get; set; }
}
here is the inherited Employer class
public class Employer : User
{
public Employer()
{
DepartmentsToPost = new Collection<Department>();
Contacts = new Collection<Contact>();
}
[Display(Name = "Workplaces to advertise jobs")]
public virtual ICollection<Department> DepartmentsToPost { get; set; }
public int EmpAccountId { get; set; }
[ForeignKey("EmpAccountId")]
public virtual Account Account { get; set; }
public override string UserType
{
get { return "Employer"; }
}
}
User Table:
UserId
Username
FirstName
Surname
EmpAccountId
Discriminator
Account Table
AccountId
Name
PrimaryUserId
There is one link back to the User table - this is for the PrimaryUser field, and this is correct. There are two other relationships: Account -> Employers. EF has named them Account_Employers and Employer_Account. These are duplicates.
How can I prevent this occuring?

The Employers collection should be decorated with InversePropertyAttribute to point to the navigational property on the other side.
public class Account
{
public int AccountId { get; set; }
[Required(ErrorMessage = Constants.ValidationMessages.FieldRequired)]
public string Name { get; set; }
public int? PrimaryUserId { get; set; }
[ForeignKey("PrimaryUserId")]
public Employer PrimaryUser { get; set; }
[InverseProperty("Account")]
public ICollection<Employer> Employers { get; set; }
}

Related

NET Core identity grouping of users

I currently have a project that uses identity and individual users have access to their own resources (sub database table linked by application user id). I'd like each user who signs up (admin) to then be able to invite new users to their 'group' and all share the same resource.
I'm looking at implementing a 'Groups' and 'UserGroups' table similar to the current 'Roles' and 'UserRoles' tables. Does the following code look ok to achieve this?
public class ApplicationUser : IdentityUser
{
[MaxLength(30)]
public string FirstName { get; set; }
[MaxLength(30)]
public string LastName { get; set; }
[MaxLength(100)]
public string Company { get; set; }
[MaxLength(30)]
public string Telephone { get; set; }
[MaxLength(15)]
public string Postcode { get; set; }
public DateTime Created { get; set; } = DateTime.UtcNow;
public DateTime PasswordResetTime { get; set; } = DateTime.UtcNow;
public bool PasswordReset { get; set; } = false;
public virtual ICollection<GSMSite> GSMSites { get; set; }
}
public class UserGroups
{
public virtual ApplicationUser ApplicationUser { get; set; }
public virtual Groups Groups { get; set; }
}
public class Groups
{
public Guid Id { get; set; }
[MaxLength(30)]
public string Name { get; set; }
}
You are trying to achieve Many to Many relationship.
Firstly by convention You should name Classes with singular form:
UserGroups -> UserGroup
Groups -> Group
You should also put ICollection<UserGroup> in both AplicationUser and Group:
public virtual ICollection<UserGroup> UserGroups
And change UserGroup to:
public class UserGroup
{
public Guid ApplicationUserId { get; set;}
public virtual ApplicationUser ApplicationUser { get; set; }
public Guid GroupId { get; set; }
public virtual Groups Groups { get; set; }
}
And then the resource You are talking about should be linked to Group not ApplicationUser.

Which one is the correct one-to-many relation in EF

i am designing a system and one of my entity has one to many relation as shown below.
public class Product
{
public int Id { get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
public Product Product { get; set; }
}
competitorProduct indicates that product has a equivalent which is sold by different store. should i define one-to-many relation as shown above or below? which one is correct?
public class Product
{
public int Id { get; set; }
public virtual ICollection<CompetitorProduct> CompetitorProducts{ get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
}
Assuming it is a one to many relationship (what would happen if a competitor product was competing with more than one of your products for example) you can do both and add in a foreign key as well.
public class Product
{
public int Id { get; set; }
public virtual ICollection<CompetitorProduct> CompetitorProducts { get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
public int ProductId { get; set; }
public virtual Product Product { get; set; }
}
You can then set up your relationship using fluent API as so:
modelBuilder.Entity<CompetitorProduct>(entity =>
{
entity.HasOne(e => e.Product)
.WithMany(e => e.CompetitorProducts)
.HasForeignKey(e => e.ProductId)
.HasConstraintName("FK_ComptetitorProduct_Product");
});
This way you can access the competitor products from the product and the product from the competitor products.
Here is a quick example of a ecommerce site I have worked on and how we did table relations.
I removed a bunch of the fields so you can see what you really need. Once to make relations and run Add-Migration EF will handle the FK constraints for you as long as you identified them in models like how I have below.
public class ApplicationUser : IdentityUser
{
public ApplicationUser()
{
Active = true;
CreateDateTimeUtc = DateTime.UtcNow;
ModifiedDateTimeUtc = DateTime.UtcNow;
}
[StringLength(500)]
public string FirstName { get; set; }
[StringLength(500)]
public string LastName { get; set; }
[StringLength(1000)]
public string Address { get; set; }
[StringLength(100)]
public string Unit { get; set; }
[StringLength(250)]
public string City { get; set; }
[StringLength(25)]
public string State { get; set; }
[StringLength(20)]
public string ZipCode { get; set; }
//This will give access to a list of child carts a user could have
[Index]
public bool Active { get; set; }
public virtual ICollection<Cart> Carts { get; set; }
// Account Profile Image
public byte[] ProfileImage { get; set; }
[StringLength(500)]
public string ProfileFilename { get; set; }
[StringLength(100)]
public string ProfileMimeType { get; set; }
}
[Table("Cart", Schema = "dbo")]
public class Cart : AbstractTable
{
public Cart()
{
IsComplete = false;
}
//This create relation to user table where I can get one unique user.
[StringLength(128)]
[ForeignKey("ApplicationUser")]
public string UserId { get; set; }
public virtual ApplicationUser ApplicationUser { get; set; }
//These link us to child tables of Cart where we can get a LIST of the items below
public virtual ICollection<CartCategory> CartCategories { get; set; }
public virtual ICollection<CartItem> CartItems { get; set; }
// Marked when a payment/receipt is generated based off of this cart
public bool IsComplete { get; set; }
}
[Table("CartItem", Schema = "dbo")]
public class CartItem : AbstractTable
{
//This will return one unique cart id and let us access it as the parent record
[ForeignKey("Cart")]
public Guid CartId { get; set; }
public virtual Cart Cart { get; set; }
// Signifies if this was paid for in a receipt
public bool IsComplete { get; set; }
public virtual ICollection<CartItemCustomField> CustomFields { get; set; }
}

How to fully construct the newly added Entity

In my project i need to add Sales leads to the data context. The sales person user adds the leads and I need to send the email to manager for the Lead.
public partial class Lead
{
public Lead()
{
this.LeadActivities = new HashSet<LeadActivity>();
}
public long LeadID { get; set; }
public System.DateTime CreatedAt { get; set; }
public long CompanyID { get; set; }
public long ProductID { get; set; }
public long CreatedByUserID { get; set; }
public string Remarks { get; set; }
public LeadStatusEnum StatusID { get; set; }
public virtual Company Company { get; set; }
public virtual Product Product { get; set; }
public virtual User User { get; set; }
public virtual ICollection<LeadActivity> LeadActivities { get; set; }
}
[Serializable]
public partial class Person
{
public Person()
{
this.Contacts = new HashSet<Contact>();
this.Users = new HashSet<User>();
}
public long PersonID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Designation { get; set; }
public Nullable<int> Gender { get; set; }
public Nullable<int> Title { get; set; }
public int StatusID { get; set; }
public string Thumbnail { get; set; }
public string Email { get; set; }
public virtual ICollection<Contact> Contacts { get; set; }
public virtual ICollection<User> Users { get; set; }
}
In the above entity, I have property UserID that is associated to Person table through CreatedByUserID. When I add the new lead, by following code, the User field remains null. Do I need to reconstruct it? if yes then how.
Edit1
Entity Creation is done by following code
Entity = new Model.Lead
{
CreatedAt = DateTime.Now,
CreatedByUserID = SessionManagement.GeneralSession.UserDetail.UserID
};
Entity.CreatedAt = Convert.ToDateTime(txtTimestamp.Value);
Entity.CompanyID = Convert.ToInt64(ddlCompany.SelectedValue);
Entity.CreatedByUserID = Convert.ToInt64(ddlUser.SelectedValue);
Entity.ProductID = Convert.ToInt64(lstProducts.SelectedValue);
Entity.Remarks = txtRemarks.Text;
DataSource.Leads.Add(Entity);
DataSource.SaveChanges();
Virtual lazy loading only works with proxy instances. Since you're explicitly constructing your Lead entity, lazy loading of the User navigation property after inserting the entity will not work.
Instead, you should use the DbSet.Create method to new up an instance of the derived proxy type. Then perform your insert, which will attach to the context, and lazy loading will subsequently work.
Alternatively, you can use your existing POCO, perform the insert and then fetch your inserted entity as its proxy from the DbSet by using the DbSet.Find method.
You should also check and make sure your foreign key id and navigation properties are correctly mapped, since properties CreatedByUserID and User would not be automatically associated by convention.

Entity Framework many to many to single object

I am trying to map a property on a user that that has a many to many relationship in the database but there is only ever one per user. But I am unable to figure out the required map in entityframework. I have the following entities:
public class User
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
//Need to map this property
public virtual SecurityRole SecurityRole { get; set; }
}
public class SecurityRole
{
public int Id { get; set; }
public string Name { get; set; }
}
An the following tables:
User:
Id
FirstName
LastName
SecurityRole:
Id
Name
UserSecurityRole:
UserId
SecurityRoleId
If anyone has any idea or could point me in the right direction that would be great
Even if there is only one record in the database, if you have a many to many relationship between User and SecurityRole it should work like this:
public class User
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public List<SecurityRole> SecurityRoles { get; set; }
}
public class SecurityRole
{
public int Id { get; set; }
public string Name { get; set; }
public List<User> Users { get; set; }
}

Relationship between tables

I use sqlmembership provider and that creates some tables. I need its user table.
My application has three types of users: teachers, students and other users. So I thought of three tables for them.
Each of them has a username which is registered by membership provider and saved in its own tables.
Now I don't know how to make the relationship between teachers or students tables to their usernames saved in the table of memberships, using entity framework.
I thought I can add a one to one relationship between users table created by membership provider and my tables after reverse engineering created tables by it to code first, but it seems is not allowed to change those tables.
Can someone show me how to make a relationship between teachers or students to their usernames (I mean their membership information)?
More Details: here are code first tables
public class aspnet_Users
{
public aspnet_Users()
{
this.aspnet_PersonalizationPerUser = new List<aspnet_PersonalizationPerUser>();
this.aspnet_Roles = new List<aspnet_Roles>();
}
public System.Guid ApplicationId { get; set; }
public System.Guid UserId { get; set; }
public string UserName { get; set; }
public string LoweredUserName { get; set; }
public string MobileAlias { get; set; }
public bool IsAnonymous { get; set; }
public System.DateTime LastActivityDate { get; set; }
public virtual aspnet_Applications aspnet_Applications { get; set; }
public virtual aspnet_Membership aspnet_Membership { get; set; }
public virtual ICollection<aspnet_PersonalizationPerUser> aspnet_PersonalizationPerUser { get; set; }
public virtual aspnet_Profile aspnet_Profile { get; set; }
public virtual ICollection<aspnet_Roles> aspnet_Roles { get; set; }
}
public class Techer
{
[Key]
public int TeacherId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string NationalNumber { get; set; }
public string PhoneNumber { get; set; }
public string Description { get; set; }
public int OfficeId { get; set; }
public virtual Office Office { get; set; }
}
public class Student
{
public int StudentId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int OfficeId { get; set; }
public virtual Office Office { get; set; }
}
I've encountered a similar scenario, and what I ended up doing is creating a foreign key from my user profile table(s) to the membership table. So for example, the Teacher table would have a column called MembershipId, and it would foreign key to the Id column in the membership table. Then, in the Register action of my AccountController, I have something like this:
if (db.Memberships.Any(x => x.UserName == model.UserName)
{
// handle error here
// return view with error message "user name already in use"
}
var token = WebSecurity.CreateUserAndAccount(model.UserName, model.Password, null, true);
var membership = db.Memberships.SingleOrDefault(x => x.UserName == model.UserName);
if (membership != null)
{
var newProfile = new Teacher
{
Membership = membership
// add other properties here if required
}
db.Teachers.Add(newProfile);
db.SaveChanges();
}
*This code is untested, as I don't have VS available at the moment, but should be enough to get you on the right track.

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