Ggtcf

Problem

I want to implement a foreign key of IdentityDb tables to other tables which are used by a different contextdb.

I have 2 DB Contexts, one is the default one (I created an MVC 5 project with individual user account project template) and the other is a context created by myself, which uses other tables than the default context.

In the ApplicationDbContext, we have the AspNetUsers table, which has a number of columns, but the one that I am interested is Id. In the other ContextDB, I have a table called Checkout, which also has a number of columns and the one I am interested with is Id. Now, I want to implement a many to many relationship. So, I created another table lets call CheckoutProducts table which has a UserId column, which would be a foreign key referencing the primary key in the AspNetUsers and I have CheckoutId which would the same be a foreign key that is referencing to the primary key in Checkout table.

How may I do the above in code?

Script

public class CheckoutUsers
 
 [Key, Column(Order = 0)]
 [ForeignKey("User")]
 [MaxLength(128)]
 public string UserId get; set; 

 [Key, Column(Order = 1)]
 [ForeignKey("Checkout")]
 public int CheckoutId get; set; 

 public virtual ApplicationUser User get; set; 
 public virtual Checkout Checkout get; set; 
 

When I run the application it returns:

System.Data.Entity.ModelConfiguration.ModelValidationException: 'One or more validation errors were detected during model generation:
ShopOnline.App_Start.IdentityUserLogin: : EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType.
ShopOnline.App_Start.IdentityUserRole: : EntityType 'IdentityUserRole' has no key defined. Define the key for this EntityType.
CheckoutUsers_User_Source: : Multiplicity is not valid in Role 'CheckoutUsers_User_Source' in relationship 'CheckoutUsers_User'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be '*'.
IdentityUserLogins: EntityType: EntitySet 'IdentityUserLogins' is based on type 'IdentityUserLogin' that has no keys defined.
IdentityUserRoles: EntityType: EntitySet 'IdentityUserRoles' is based on type 'IdentityUserRole' that has no keys defined.
'

To mention that if I remove this table or I just remove the field ApplicationUser User then everything works fine in terms that I don't have an error, nor my UserId has a foreign key in other tablet