In our businessslogic we have some contacts row that may have a relationship with one billing row (0..N).
Here the contact class
public class ESUsersContact
{
[Key]
public int Id { get; set; }
[ForeignKey("Billing")]
public int? BillingId { get; set; }
public string Title { get; set; }
public string Name { get; set; }
public string Address { get; set; }
public string Email { get; set; }
public string City { get; set; }
public string PostalCode { get; set; }
public string Phone { get; set; }
public string CellPhone { get; set; }
public string Fax { get; set; }
public ES.Enums.BusinessESCommon.Language.AllLanguage Language { get; set; }
public virtual ICollection<ESUsersCompany> Companies { get; set; }
public virtual ESUsersBilling Billing { get; set; }
}
Here is the billing class
[Key, Column(Order = 0)]
[ForeignKey("Company")]
public int CompanyId { get; set; }
[Key, Column(Order = 1)]
public ES.Enums.BusinessESUsers.Billing.Type Type { get; set; }
public ES.Enums.BusinessESUsers.Billing.Payment PaymentType { get; set; }
public ES.Enums.BusinessESUsers.Billing.Frequency PaymentFrequency { get; set; }
public decimal Amount { get; set; }
public bool IsFreeTrial { get; set; }
public DateTime FreeTrialEndDate { get; set; }
public DateTime? NextPaymentDate { get; set; }
public virtual ESUsersCompany Company { get; set; }
public virtual ICollection<ESUsersContact> Contacts { get; set; }
}
However, I receive this error doing so.
The relationship from 'ESUsersContact.Billing' to 'ESUsersBilling.Contacts' with foreign key properties {'BillingId' : Nullable<int>} cannot target the primary key {'CompanyId' : int, 'Type' : Type} because it is not compatible. Configure a principal key or a set of compatible foreign key properties for this relationship.
I don't understand why the error occurs and state the primary key {'CompanyId' : int, 'Type' : Type}.
ESUsersContact.Billing class has a composite key. ESUsersContact has to map both of the foreign keys. CompanyId and Type. You can not refer only one column since ESUsersContact.Billing has two columns for the key.
Related
I have two model classes:
public partial class customer
{
public string customer_id { get; set; } // Primary Key
public string customer_name { get; set; }
public string course_mobile { get; set; }
public List<customer_address> customer_addresses { get; set; }
}
public partial class customer_address
{
public string address_id { get; set; } // Primary Key
public string adreess { get; set; }
public customer customer { get; set; }
public string customer_id { get; set; } // Foreign Key
}
I get an error:
The entity type 'customer' requires a primary key to be defined.
So how it solve?
Datbase table structure
You need to add [Key] attrubute.
public partial class customer
{
[Key]
public string customer_id { get; set; } // Primary Key
public string customer_name { get; set; }
public string course_mobile { get; set; }
public List<customer_address> customer_addresses { get; set; }
}
public partial class customer_address
{
[Key]
public string address_id { get; set; } // Primary Key
public string adreess { get; set; }
public customer customer { get; set; }
public string customer_id { get; set; } // Foriegn Key
}
I have two model class as;
public class MessageDetailModel
{
[Key]
public int messageDetailsId { get; set; }
public MessageModel messageModel { get; set; }
public string detail { get; set; }
public int senderId { get; set; }
public int customerId { get; set; }
public string phone { get; set; }
public DateTime date { get; set; }
}
and
public class MessageModel
{
[Key]
public int messageId { get; set; }
public int senderId { get; set; }
public int customId { get; set; }
public bool ReadInfo { get; set; }
public virtual List<MessageDetailModel> MessageDetails { get; set; }
}
and it is my context class ;
public virtual DbSet<MessageDetailModel> messageDetails { get; set; }
public virtual DbSet<MessageModel> messages { get; set; }
public virtual DbSet<PersonModel> persons { get; set; }
public virtual DbSet<DirectoryModel> directory { get; set; }
I am trying to get messageId over MessageDetailModel but messageId returns as 0 and I have that error "Object reference not set to an instance of an object"
Console.WriteLine(k.messageModel.messageId); //( k is my var which gets from messagedetail model)
How can ı reach messageId over MessadeDetailModel
There is no current link between your two models that would represent a Foreign Key.
You'd need to do something like this for your model if you want a Foreign Key to link to the related object:
public class MessageDetailModel
{
[Key]
public int messageDetailsId { get; set; }
[ForeignKey("messageId")] // Added Data Annotation for the Foreign Key relationship
public MessageModel messageModel { get; set; }
public string detail { get; set; }
public int senderId { get; set; }
public int customerId { get; set; }
public string phone { get; set; }
public DateTime date { get; set; }
public int messageId { get; set; } // This would be your Foreign Key
}
I've added the messageId column to your MessageDetailModel to match the Primary Key column of your MessageModel as that's necessary for the link to form.
You would use the [ForeignKey("messageId")] Data Annotation above the variable for the MessageModel to determine what value it needs to use when finding the object you want.
I'm a newbie to designing database.
I have problem how to define a domain class which has multiple foreign keys linked with a same primary key.
Here is my model:
namespace OceanFmsSystem.Domain
{
public class ExportTemplate
{
public int Id { get; set; }
public List<ExportBooking> ExportBookings { get; set; }
public string TemplateName { get; set; }
public int CustomerId { get; set; }
public string Incoterms { get; set; }
public string IncotermsDetail { get; set; }
public string PaymentTerm{ get; set; }
public int CountryOriginId { get; set; }
public int CountryDestinationId { get; set; }
}
}
What I want to do is that CountryOriginId & CountryDestinationId should refer to the below class as foreign keys:
namespace OceanFmsSystem.Domain
{
public class Country
{
public int Id { get; set; }
public string CountryCode { get; set; }
public string CountryName { get; set; }
}
}
As far as I know, in EF Core there is an convention which I should name a foreign key as below for migration from code to database.
public type ClassNameOfPrimaryKeyId { get; set;}
Is there any possible way to make this happens?
Yes, possible. Your class should look like this:
public class ExportTemplate
{
//...
public int CountryOriginId { get; set; }
public Country CountryOrigin { get; set; }
public int CountryDestinationId { get; set; }
public Country CountryDestination { get; set; }
}
EF is smart enough to figure the Ids by convention. If you do not wish to follow the convention you can use [ForeignKey] attribute on the properties to configure the FK:
[ForeignKey("Origin")]
public int MyOriginId { get; set; }
public Country Origin { get; set; }
I use code-first approach. I want to use just ObjectId property in ObjectScore as foreign key for three relations with Professor (Id) , College (Id) and EducationalGroup (Id), like what's happening at SQL
CONSTRAINT [FK_ObjectScore_Colege] FOREIGN KEY([ObjectId])
CONSTRAINT [FK_ObjectScore_Professer] FOREIGN KEY([ObjectId])
CONSTRAINT [FK_ObjectScore_EducationGroup] FOREIGN KEY([ObjectId])
How to make this relation in Entity Framework (data annotations or fluent api)?
Thanks all
public class Professor : Person
{
public int ProfessorCode { get; set; }
public virtual ICollection<EducationalGroup> EducationalGroups { get; set; }
public virtual ICollection<College> Colleges { get; set; }
public virtual ICollection<ObjectScore> ObjectScores { get; set; }
}
public class College : BaseClass
{
public int CollegeCode { get; set; }
public virtual ICollection<Professor> Professors { get; set; }
public virtual ICollection<EducationalGroup> EducationalGroups { get; set; }
public virtual ICollection<ObjectScore> ObjectScores { get; set; }
}
public class EducationalGroup : BaseClass
{
public int CollegeCode { get; set; }
public virtual ICollection<Professor> Professors { get; set; }
public virtual College College { get; set; }
public virtual ICollection<ObjectScore> ObjectScores { get; set; }
}
public class ObjectScore
{
public Guid Id { get; set; }
public int CurrentScore { get; set; }
public virtual Term Term { get; set; }
public virtual Score Score { get; set; }
public int ObjectId { get; set; }
}
and my BaseClass and Person classes:
public class Person : BaseClass
{
public string Family { get; set; }
}
public class BaseClass
{
public BaseClass()
{
IsActive = false;
}
public int Id { get; set; }
public string Name { get; set; }
public DateTime? CreationDate { get; set; }
public DateTime? LastModifiedDate { get; set; }
public bool IsActive { get; set; }
}
I'm still new in creating Models using Entity Framework and MVC 4 Razor. I'm having a problem on how can I save a history of a model. How can I create a model that have a history on specific tables or fields ? For ex: If I wish to create a history on the changes on the school. Its still not clear to me how will I I create the model that saves history. How will be the triggering do I have to execute the save function on different models with the same data ?
Thank you so much in advance.
If anyone could be a simple example of model and a model history and how it is functioning, I'll be very grateful. Like a Sales or sales history.
Here's my code
One To Many
public class Child
{
[Key]
public int ChildID { get; set; }
[Required,Display(Name="Project Code")]
public string ProjectCode { get; set; }
public string Status { get; set; }
[DataType(DataType.Date)]
public DateTime StatusDate { get; set; }
public string FamilyName { get; set; }
public string GivenName { get; set; }
public string MiddleName { get; set; }
[DataType(DataType.Date)]
public DateTime Birthdate { get; set; }
public string Gender {get;set;}
public string Address { get; set; }
public string Section { get; set; }
public int SchoolLevelID { get; set; }
public int SchoolYearID { get; set; }
public int AreaID { get; set; }
public int SchoolID { get; set; }
public int GradeLevelID { get; set; }
//Foreign Key - One to Many
public virtual SchoolLevel SchoolLevel { get; set; }
public virtual SchoolYear SchoolYear { get; set; }
public virtual Area Area { get; set; }
public virtual School School { get; set; }
public virtual GradeLevel GradeLevel{get;set;}
//Child is foreign key at the table
public virtual ICollection<Guardian> Guardians { get; set; }
}
public class SchoolLevel
{
public int SchoolLevelID { get; set; }
public string SchoolLevelName { get; set; }
public virtual ICollection<Child> Children { get; set; }
}
public class SchoolYear
{
public int SchoolYearID { get; set; }
public string SchoolYearName { get; set; }
public virtual ICollection<Child> Children{get;set;}
}
public class Area
{
public int AreaID{get;set;}
public string AreaName { get; set; }
public virtual ICollection<Child> Children{get;set;}
}
public class School
{
public int SchoolID { get; set; }
public string SchoolName{get;set;}
public virtual ICollection<Child> Children { get; set; }
}
public class GradeLevel
{
public int GradeLevelID{get;set;}
public string GradeLevelName { get; set; }
public virtual ICollection<Child> Children { get; set; }
}
public class ChildDbContext : DbContext
{
public DbSet<Child> Children { get; set; }
public DbSet<SchoolLevel> SchoolLevels { get; set; }
public DbSet<SchoolYear> SchoolYears { get; set; }
public DbSet<Area> Areas { get; set; }
public DbSet<School> Schools { get; set; }
public DbSet<GradeLevel> GradeLevels { get; set; }
public DbSet<Guardian> Guardians { get; set; }
}
You can use this approach: Create a History model. That contains 1 changeness like o log.
public class History
{
public int HistoryId { get; set; }
public int ModelType { get; set; } //it is ModelTypeEnum value.
public int ModelId { get; set; }
public string PropertyName { get; set; }
public string Propertyvalue {get;set;}
public DateTime ChangeDate { get; set; }
public int ChangedUserId { get; set; }
}
And Enum:
public enum ModelTypeEnum
{
Child =1,
SchoolLevel = 2,
//etc..
};
For example, when you edit 1 Child entity, give changed properties name and value, it's id, type and others (ChangeDate, ChangedUserId) to History and save histories. If 3 properties will change you should save 3 history entities. Then, you can load (filter) histories by ModelId, by ChangedUserId etc.