I've got a little problem with my database design in an EntityFramework6 project. These are my two code first classes I use to create the database with. As you can see the Details class violates all normal forms out there and I want to split it up properly, however I have no idea how to do it properly, since I am totally new to SQLServer and EF.
So what is the best way to get a decent database design which I then could query?
internal class LocationDataContract
{
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public DbGeography Coordinates { get; set; }
public LocationsDetailsDataContract Details { get; set; }
}
internal class LocationDetailsDataContract
{
[Key, ForeignKey("Location")]
public Guid Id { get; set; }
public string Planet { get; set; }
public bool? IsCapital { get; set; }
public int Population { get; set; }
public string System { get; set; }
public string Sector { get; set; }
public LocationDataContract Location { get; set; }
}
Updated Question below
So following the advice of George I did the following. Would this be a decent solution. I Have to add, that I need to to some converting since the application uses different (completely inheritance based) models, which I have to use since a database is not the only source of data and said data uses yet another format to store data which I can't change.
internal class LocationDataContract
{
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public DbGeography Coordinates { get; set; }
public LocationsDetails Details { get; set; }
}
internal abstract class LocationDetailDataContract
{
[Key, ForeignKey("Location")]
public Guid Id { get; set; }}
public LocationsDetails Details { get; set; }
}
internal class CityDetailDataContract : LocationDetailDataContract
{
public string Planet { get; set; }
public bool? IsCapital { get; set; }
public int Population { get; set; }
}
internal class PlantDetailDataContract : LocationDetailDataContract
{
public int Population { get; set; }
public string System { get; set; }
}
internal class SystemDetailDataContract : LocationDetailDataContract
{
public string Sector { get; set; }
}
internal class SectorDetailDataContract : LocationDetailDataContract
{
// For now nothing
}
#Ruhrpottpatriot, why all classe are inheriting from LocationDetailDataContract?
Doing this i believe you will have a buch of classes and tables but the data will remain desnormalized (ex: CityDetailDataContract will have the column Planet with repeated strings.
Are you allowed to do something like this from you original question?
internal class LocationDataContract
{
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public DbGeography Coordinates { get; set; }
public LocationDetailsDataContract Details { get; set; }
}
internal class LocationDetailsDataContract
{
[Key, ForeignKey("Location")]
public Guid Id { get; set; }
public Planet Planet { get; set; }
public System System { get; set; }
public Sector Sector { get; set; }
[Required]
public LocationDataContract Location { get; set; }
}
internal class Planet {
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
public bool? IsCapital { get; set; }
public int Population { get; set; }
}
internal class System {
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
}
internal class Sector {
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
}
Related
I have problem when I try to migrate my model in EF Core 2.0.
public class Profile
{
[Key]
public Guid Id { get; set; }
public Guid UserId { get; set; }
public ExternalUser User { get; set; }
}
public class OrganizationCustomerProfile : Profile
{
public string CompanyName { get; set; }
public Address LegalAddress { get; set; }
public Address ActualAddress { get; set; }
public BusinessRequisites Requisites { get; set; }
public string President { get; set; }
public IEnumerable<ContactPerson> ContactPerson { get; set; }
}
public class PersonCustomerProfile : Profile
{
public FullName Person { get; set; }
public Address Address { get; set; }
public string PhoneNumber { get; set; }
}
public class ContactPerson
{
[Key]
public Guid Id { get; set; }
public FullName Person { get; set; }
public string Rank { get; set; }
public string Email { get; set; }
public string PhoneNumber { get; set; }
public Guid ProfileId { get; set; }
public Profile Profile { get; set; }
}
Here I want to add complex datatypes Address and BusinessRequisites, which are:
public class BusinessRequisites
{
public string OGRN { get; set; }
public string INN { get; set; }
public string KPPCode { get; set; }
public string SettlementAccount { get; set; }
public string RCBIC { get; set; }
public string CorrespondentAccount { get; set; }
public string BankName { get; set; }
}
public class Address
{
public string FullAddress { get; set; }
public float Latitude { get; set; }
public float Longtitude { get; set; }
}
Code which I use for TPH binding:
public DbSet<Profile> UserProfiles { get; set; }
public DbSet<ContactPerson> ContactPerson { get; set; }
public DbSet<OrganizationCustomerProfile> OrganizationCustomerProfile { get; set; }
...
modelBuilder.Entity<Profile>().HasKey(u => u.Id);
modelBuilder.Entity<OrganizationCustomerProfile>().OwnsOne(e => e.ActualAddress);
modelBuilder.Entity<OrganizationCustomerProfile>().OwnsOne(e => e.LegalAddress);
modelBuilder.Entity<OrganizationCustomerProfile>().OwnsOne(e => e.Requisites);
But when I try to make a migration, I get an error:
"Cannot use table 'UserProfiles' for entity type
'OrganizationCustomerProfile.ActualAddress#Address' since it has a
relationship to a derived entity type 'OrganizationCustomerProfile'.
Either point the relationship to the base type 'Profile' or map
'OrganizationCustomerProfile.ActualAddress#Address' to a different
table."
So, what the reason of this error? Is it not possible to create hierarchy inheritance in EF Core 2.0?
Thank you!
It seems like this isn't supported at the moment:
https://github.com/aspnet/EntityFrameworkCore/issues/9888
I have an attribute which looks like this:
public class CameraAttribute
{
public int Id { get; set; }
public int ProductId { get; set; }
public string CompatibleMemory { get; set; }
[MaxLength(255)] public string WhiteBalance { get; set; }
[MaxLength(255)] public string SceneModes { get; set; }
[MaxLength(255)] public string ShootingModes { get; set; }
[MaxLength(100)] public string PhotoEffects { get; set; }
[MaxLength(255)] public string CameraPlayback { get; set; }
public bool Tripod { get; set; }
public bool DirectPrinting { get; set; }
[MaxLength(50)] public string Colour { get; set; }
public CameraAttributePicture Picture { get; set; }
public CameraAttributeVideo Video { get; set; }
public CameraAttributeAudio Audio { get; set; }
public CameraAttributeBattery Battery { get; set; }
public CameraAttributeDimension Dimensions { get; set; }
public CameraAttributeDisplay Display { get; set; }
public CameraAttributeLightExposure Exposure { get; set; }
public CameraAttributeFlash Flash { get; set; }
public CameraAttributeFocusing Focusing { get; set; }
public CameraAttributeInterface Interface { get; set; }
public CameraAttributeLens Lens { get; set; }
public CameraAttributeNetwork Network { get; set; }
public CameraAttributeShutter Shutter { get; set; }
[ForeignKey("ProductId")] public Product Product { get; set; }
}
and the Audio looks like this:
public class CameraAttributeAudio
{
public int Id { get; set; }
public int AttributeId { get; set; }
[MaxLength(50)] public string SupportedFormats { get; set; }
[ForeignKey("AttributeId")] public CameraAttribute Attributes { get; set; }
}
I have set up some mapping in my DbContext like this:
modelBuilder.Entity<CameraAttribute>().HasRequired(m => m.Audio).WithRequiredPrincipal(m => m.Attributes).WillCascadeOnDelete(true);
but when I try to run the command add-migration I get this error:
CameraAttribute_Audio_Target: : Multiplicity is not valid in Role 'CameraAttribute_Audio_Target' in relationship 'CameraAttribute_Audio'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be '*'.
As you can see from the Attribute class all the properties throw this error.
Does anyone know why and how I can resolve it?
I think the problem is that CameraAttributeAudio class has its own Id property as well while it is unnecessary in a one-to-one relationship because AttributeId can identify both the CameraAttribute and the CameraAttributeAudio. It should use the AttributeId as its primary [Key].
public class CameraAttributeAudio
{
[Key]
[ForeignKey("Attributes")]
public int AttributeId { get; set; }
[MaxLength(50)]
public string SupportedFormats { get; set; }
public CameraAttribute Attributes { get; set; }
}
I moved the [ForeignKey] attribute to the AttributeId property so that the annotations are in one place. Although it is also correct to have it on the Attributes property.
I'm working on a project where the MongoDB model will be similar to Facebook. So we all know how FB works, a user "likes" a band/company page, and that user will see all the posts from that page.
Is the below model how I should design this?
If a Page has million likes, then each Post will have a million sub documents of Like. That does not seem right, there must be a better way that I cant think of.
Thanks.
public class Person
{
public ObjectId Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
public class Page
{
public ObjectId Id { get; set; }
public string Name { get; set; }
public List<Like> PersonLikes { get; set; }
}
public class Like
{
public ObjectId Id { get; set; }
public ObjectId UserId { get; set; }
public DateTime DateLiked { get; set; }
}
public class Post
{
public ObjectId Id { get; set; }
public ObjectId PageId { get; set; }
public string Message { get; set; }
public List<Like> PersonLikes { get; set; }
}
My take assuming you only want to track likes
public class Page
{
public ObjectId Id { get; set; }
public DateTimeOffset Date { get; set; }
public string Name { get; set; }
public int NumberOfLikes { get; set; }
}
public class Post
{
public ObjectId Id { get; set; }
public ObjectId PageId { get; set; }
public DateTimeOffset Date { get; set; }
public string Message { get; set; }
public int NumberOfLikes { get; set; }
}
I would then queue the Reaction (Like or Dislike) for insertion, "sentiment" information doesn't have to be stored in real time, does it? These are not medications, bank transactions, etc.
public class Like
{
public ObjectId Id { get; set; }
public ObjectId ParentId { get; set;}
public ObjectId UserId { get; set; }
public DateTimeOffset Date { get; set; }
}
Queue where? to a collection of Likes. Why not part of the page or post? Because if a post goes viral (as you said even though the majority won't), you may end up with a 1,000,000 likes. Who is going to browse this information other than an analytic engine?
You also have to ensure a user can only express their reaction only once per item.
The post only exists on one page so it´s the page that should own the post, not the post owning the page.
public class Person
{
public ObjectId Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
public class Page
{
public ObjectId Id { get; set; }
public string Name { get; set; }
public List<Like> PersonLikes { get; set; }
public List<Post> Posts { get; set; }
}
public class Post
{
public ObjectId Id { get; set; }
public string Message { get; set; }
public List<Like> Likes { get; set; }
}
public class Like
{
public ObjectId Id { get; set; }
public ObjectId UserId { get; set; }
public DateTime DateLiked { get; set; }
}
I am a VB.NET programmer, but I am trying to learn C# and MVC in my spare time. I am using ASP.NET MVC 5.1.0.0 and I am trying to do code-First database creation in a local instance of SQL Server.
I was able to get the first database table to update in the database when I ran Update-Database from within the IDE, but when I added a second table that has a PK/FK relationship with the first, I am getting a red line under [ForeignKey] which reads
Does not contain a constructor that takes 1 arguments
I have been searching all over and not getting anywhere. Any suggestions or help would be appreciated. By the way, the first table is a PK/FK relationship to the AspNetUsers table.
public class BuildDatabase : IdentityUser
{
public virtual Companies Companies { get; set; }
public virtual NotaryProfile NotaryProfile { get; set; }
}
public class Companies
{
[Key]
[Column("CompanyID")] // Did this as the database will reflect TableName_ColumnName instead.
public int CompanyID { get; set; }
public string CompanyName { get; set; }
public bool IsActive { get; set; }
public bool IsNotary { get; set; }
public virtual ICollection<NotaryProfile> NotaryProfile { get; set; }
}
public class NotaryProfile
{
[Key]
public int NotaryID { get; set; }
public string NamePrefix { get; set; }
public string FirstName { get; set; }
public string MiddleInitial { get; set; }
public string LastName { get; set; }
public string NameSuffix { get; set; }
public bool IsActive { get; set; }
public int DefaultState { get; set; }
public int DefaultCounty { get; set; }
public bool IsSigningAgent { get; set; }
public bool HasABond { get; set; }
public decimal BondAmount { get; set; }
public bool HasEandO { get; set; }
public decimal EandOAmount { get; set; }
public bool ElectronicNotarizationsAllowed { get; set; }
public string ElectronicTechnologyUsed { get; set; }
public string ComissionNumber { get; set; }
public DateTime CommissionIssued { get; set; }
public DateTime CommssionOriginal { get; set; }
public DateTime CommissionExpires { get; set; }
public DateTime CommissionFiledOn { get; set; }
public string SOSAuditNumber { get; set; }
public string CommissionDesc { get; set; }
[Foreignkey("CompanyID")] // Companies.CompanyID = PK
public int CompanyID { get; set; } // PK/FK relationship.
public Companies Companies { get; set; } // Reference to Companies table above.
}
public class SchemaDBContext : IdentityDbContext<BuildDatabase>
{
public SchemaDBContext()
: base("DefaultConnection"){}
public DbSet<Companies> Companies { get; set; }
public DbSet<NotaryProfile> NotaryProfile { get; set; }
}
One of your classes (probably NotaryProfile) needs to reference another object (the foreign key relationship) but there is no constructor in that class that accepts an argument to establish that relationship, e.g.:
public NotaryProfile(int companyId) {
this.companyId = companyId;
}
BTW, a better way to establish that relationship is to use the actual class type rather than the ID, as in:
public class NotaryProfile {
...
public Company Company { get; set; }
// Instead of this:
// public int CompanyID { get; set; } // PK/FK relationship.
...
}
See also:
C# “does not contain a constructor that takes '1' arguments”
Does not contain a constructor that takes 2 arguments
Pardon any misspeaking I may do. I am just learning asp.net c#, OOP, and MVC 4.
I am using the Annotator plugin on my site and I am trying to store and retrieve the results from a data base. When a new annotation is created it sends information like this to the controller.
{
"text":"asdas sd a dasd as dasd",
"ranges":
[{
"start":"/div/p[3]",
"startOffset":195,
"end":"/div/p[3]",
"endOffset":532
}],
"quote":"Some quote that was selected.",
"UserID":"1",
"ProjectDocID":"1"
}
Now, I hoped something like this would load all the data into a nice easy object.
// GET: /Annotation/Create
public ActionResult Create(Comment comment)
{
db.Comments.Add(comment);
db.SaveChanges();
return Json(comment);
}
The model I had looked like this (and I am change it however it needs to be changed).
public class Comment
{
[Key]
public int CommentID { get; set; }
public int ProjectDocID { get; set; }
public int UserID { get; set; }
public string text { get; set; }
public string Annotation { get; set; }
public string quote { get; set; }
public string start { get; set; }
public string end { get; set; }
public string startOffset { get; set; }
public string endOffset { get; set; }
public DateTime DateCreated { get; set; }
public virtual ICollection<CommentVote> CommentVote { get; set; }
public virtual ICollection<CommentReply> CommentReply { get; set; }
public ProjectDoc ProjectDoc { get; set; }
public virtual User User { get; set; }
}
What do I need to do to get the data from the server and map it to the model. I also need to be able to send it back in the format at the top so the plugin understands it when it asks for it from the Details action in the controller.
Not sure if this is the right way to do it or not, but it lets me store it in the database and that's all that matter for the moment. I updated my model as follows.
public class Comment
{
[Key]
public int CommentID { get; set; }
public int ProjectDocID { get; set; }
public int UserID { get; set; }
public string text { get; set; }
public string quote { get; set; }
public DateTime DateCreated { get; set; }
public virtual ICollection<CommentVote> CommentVote { get; set; }
public virtual ICollection<CommentReply> CommentReply { get; set; }
public ProjectDoc ProjectDoc { get; set; }
public virtual User User { get; set; }
public List<ranges> ranges { get; set; }
}
public class ranges {
public int ID { get; set; }
public string start { get; set; }
public string end { get; set; }
public string startOffset { get; set; }
public string endOffset { get; set; }
}
This matches the JSON object I am sending in to the controller with Ajax. Once it matches exactly the controller action above works.