I have some problems when updating my model. This is my update code:
public void Update(Class #class)
{
var updatedClass = context.Classes.Where(c => c.ClassId == #class.ClassId).FirstOrDefault();
updatedClass.ClassPriceTypeId = #class.ClassPriceTypeId;
updatedClass.ClassType = #class.ClassType;
updatedClass.Name = #class.Name;
updatedClass.Title = #class.Title;
updatedClass.MetaTag = #class.MetaTag;
updatedClass.MetaDescription = #class.MetaDescription;
updatedClass.UrlSafe = #class.UrlSafe;
updatedClass.Header = #class.Header;
updatedClass.Margin = #class.Margin;
updatedClass.ImageName = #class.ImageName;
updatedClass.GroupId = #class.GroupId;
updatedClass.IsPublished = #class.IsPublished;
context.SaveChanges();
}
First problem is that I have made LazyLoadingEnabled=false but after fetching updatedClass the relational properties like Group is not null.
Second problem is that in some of #class objects I can easily update my entity but in some others I see this error:
The operation failed: The relationship could not be changed because
one or more of the foreign-key properties is non-nullable. When a
change is made to a relationship, the related foreign-key property is
set to a null value. If the foreign-key does not support null values,
a new relationship must be defined, the foreign-key property must be
assigned another non-null value, or the unrelated object must be
deleted.
Update
This is Class model:
public class Class
{
public int ClassId { get; set; }
public int GroupId { get; set; }
public int ClassPriceTypeId { get; set; }
public string Name { get; set; }
public string Title { get; set; }
public string MetaTag { get; set; }
public string MetaDescription { get; set; }
public string UrlSafe { get; set; }
public string Header { get; set; }
public string ImageName { get; set; }
public int Margin { get; set; }
public string ClassType { get; set; }
public bool IsPublished { get; set; }
public virtual Group Group { get; set; }
public virtual List<Product> Products { get; set; }
public virtual List<Comparing.Model.Price.Price > Prices { get; set; }
public virtual ClassPriceType.ClassPriceType ClassPriceType { get; set; }
public virtual List<Garanty> Garanties { get; set; }
public virtual List<PhoneModel> PhoneModels { get; set; }
public virtual List<ClassPartner> ClassPartners { get; set; }
public virtual List<Content> Contents { get; set; }
}
And this is Group model:
public class Group
{
public int GroupId { get; set; }
public int SectionId { get; set; }
public string Name { get; set; }
public string Title { get; set; }
public string MetaTag { get; set; }
public string MetaDescription { get; set; }
public string UrlSafe { get; set; }
public string Header { get; set; }
public string ImageName { get; set; }
public bool IsPublished { get; set; }
public virtual Section Section { get; set; }
public virtual List<Class> Classes { get; set; }
}
Can anyone help me about the problem?
I guess, you are trying to update a primary key field which is having a relation ship with other foreign key with not null constraint. I guess you need to use update cascade.
Related
I'm using Entity Framework 6.0 and have defined 2 POCO's to map to my database:
[Table("PortfolioGroups")]
public class PortfolioGroup : AuditableEntity<int>
{
[Column("Company_Id")]
public int CompanyId { get; set; }
[ForeignKey("CompanyId")]
public Company Company { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public ICollection<PortfolioGroupItem> PortfolioGroupItems { get; set; }
public PortfolioGroup()
{
PortfolioGroupItems = new Collection<PortfolioGroupItem>();
}
}
And the PortfolioGroupItem:
[Table("PortfolioGroupItems")]
public class PortfolioGroupItem : AuditableEntity<int>
{
[Column("PortfolioGroup_Id")]
public int PortfolioGroupId { get; set; }
[ForeignKey("PortfolioGroupId")]
public PortfolioGroup PortfolioGroup { get; set; }
[Column("Trademark_Id")]
public int? TrademarkId { get; set; }
[ForeignKey("TrademarkId")]
public Trademark.Trademark Trademark { get; set; }
[Column("TrademarkRegistration_Id")]
public int? TrademarkRegistrationId { get; set; }
[ForeignKey("TrademarkRegistrationId")]
public TrademarkRegistration TrademarkRegistration { get; set; }
[Column("Domain_Id")]
public int? DomainId { get; set; }
[ForeignKey("DomainId")]
public Domains.Domain Domain { get; set; }
}
However - when I attempt to query the PortfolioGroups, Entity Framework for some reason attempts to query a field named "Trademark_Id" - which doesn't exist on the PortfolioGroup entity:
Context.PortfolioGroups.SingleOrDefault(i => i.Id == id && i.CompanyId == companyId);
Throws:
Invalid column name 'Trademark_Id'.
I've used this kind of setup other places in my application without any problems. I simply cannot find out why EF is trying to query a column that's not in my entity!
Any suggestions would be greatly appreciated. I'm at the end of my rope here.
Thanks guys! :)
The problem is that you've added a Navigation Property on Trademark that requires a Foreign Key on Portfolio Group:
public class Trademark
{
[Key]
public int Id { get; set; }
[MaxLength(250)]
[Required]
public string Name { get; set; }
[MaxLength(150)]
public string Filename { get; set; }
public ICollection<PortfolioGroup> PortfolioGroups { get; set; }
public Trademark()
{
PortfolioGroups = new Collection<PortfolioGroup>();
}
}
EF expects PortfolioGorup to have a Trademark_ID column to store which PortfolioGroups are associated with a Trademark.
My EF Code First model for some reason is not in sync with the db. I'm getting this error:
{"Invalid column name 'Type_Id1'."}
The field is actually called 'Type_Id' so I'm not sure from where that 1 comes up. I have the table column called as Type_Id and also I've added a Type_Id in my type entity model.
Why might I be getting that error message, plus why I'm getting 1 at the end of the name?
Update
My Task class:
public class Task
{
public Task()
{
Language = 1;
Grades = new HashSet<Grade>();
Categories = new HashSet<Category>();
Subjects = new HashSet<Subject>();
Rooms = new Collection<Room>();
Tools = new Collection<Tool>();
}
[Key]
public int Id { get; set; }
public string Description { get; set; }
public virtual TaskType Type { get; set; }
public string Rules { get; set; }
[Required]
[StringLength(200), MinLength(1)]
public string Name { get; set; }
public int PreperationTime { get; set; }
public int InstructionTime { get; set; }
public int TaskTime { get; set; }
public int Type_Id { get; set; }
public string VideoLink { get; set; }
[Required]
public int Language { get; set; }
public int? MinimumParticipants { get; set; }
public int? MaximumParticipants { get; set; }
public int? Rating { get; set; }
[Required]
public string CreatedBy { get; set; }
public virtual ICollection<Grade> Grades { get; set; }
public virtual ICollection<Category> Categories { get; set; }
public virtual ICollection<Subject> Subjects { get; set; }
public virtual ICollection<Room> Rooms { get; set; }
public virtual ICollection<Tool> Tools { get; set; }
}
DBContext class:
public ApplicationDbContext() : base("DefaultConnection", false)
{
}
public DbSet<Task> Tasks { get; set; }
public DbSet<TaskType> TaskTypes { get; set; }
public static ApplicationDbContext Create()
{
return new ApplicationDbContext();
}
You need to add the FK attribute on your navigation property. EF is creating Type_Id1 because Type_Id already exists (although it can't tell by convention it is the FK).
[ForeignKey("Type_Id")]
public virtual TaskType Type { get; set; }
https://msdn.microsoft.com/en-us/data/jj591583.aspx#Relationships
I have these method classes:
public class Links
{
[Key]
public int LID { get; set; }
public string Link { get; set; }
public string Type { get; set; }
public string Filename { get; set; }
public virtual int RessourceId { get; set; }
}
public class Ressource
{
[Key]
public int RessourceId { get; set; }
public string TitreR { get; set; }
public string Desc { get; set; }
//public int Position { get; set; }
public int Rating { get; set; }
public string Tags { get; set; }
public virtual int SectionId { get; set; }
public virtual int UserId { get; set; }
public virtual ICollection<Links> Links { get; set; }
}
public class Section
{
[Key]
public int SectionId { get; set; }
public string Titre { get; set; }
public virtual ICollection<Tags> Tags { get; set; }
public virtual ICollection<Ressource> Ressources { get; set; }
//public Section() { this.Tag=new List<string>(); }
}
And when I want to delete a Ressource, I have this error:
The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted.
error line:
_db.Entry(R).State = EntityState.Deleted;
_db.SaveChanges(); // error line
PS: It was working before I added the Filename attribute to the Links class... Any idea how to solve it? Thank you
Make foreign key nullable (i.e. change it's type from int to int?):
public virtual int? RessourceId { get; set; }
That means you can have links without resource.
When creating many to many relationship using EF 4.3 code first approach, I cannot save data to connecting table, also cannot any examples on how to fill this table using saving object to Icollection... Here is my example:
MODELS
public class Hospital
{
//PK
[Key]
public int Id { get; set; }
public string Name { get; set; }
public string Address { get; set; }
public string City { get; set; }
public string County { get; set; }
public string UserName { get; set; }
public string Password { get; set; }
public Guid User_Id { get; set; }
//FK
public virtual ICollection<Operator> Operators { get; set; }
}
public class Operator
{
//PK
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime Dob { get; set; }
public string Email { get; set; }
//FK
public virtual ICollection<Hospital> Hospitals { get; set; }
}
public class Project: DbContext
{
public DbSet<Hospital> Hospitals { get; set; }
public DbSet<Operator> Operators { get; set; }
}
CONTROLLER
public void AddOperater()
{
Hospital h = new Hospital();
h = db.Hospitals.Single(a=>a.Id ==1);
var o = new Operator();
o.FirstName = "John";
o.LastName = "Doe";
o.Dob = new DateTime(1988,2,12);
o.Email = "johndoe#gmail.com";
o.Hospitals.Add(h);
db.SaveChanges();
}
With this approach I keep getting error here: o.Hospitals.Add(h); even when my Hospital instance is filled with data. How exactly to save data to both tables, the dbo.Operators and dbo.OperatorHospital which is relationship table?
o.Hospitals.Add(h) will fail because the list is a null list. You cannot call Add() on a null list. Typically most people get around this by instantiating the list in the constructor of the entity... like so... the current line is blowing up due to a CSharp issue.
public class Hospital
{
//PK
[Key]
public int Id { get; set; }
public string Name { get; set; }
public string Address { get; set; }
public string City { get; set; }
public string County { get; set; }
public string UserName { get; set; }
public string Password { get; set; }
public Guid User_Id { get; set; }
//FK
public virtual ICollection<Operator> Operators { get; set; }
public Hospital()
{
Operators = new List<Operator>();
}
}
public class Operator
{
//PK
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime Dob { get; set; }
public string Email { get; set; }
//FK
public virtual ICollection<Hospital> Hospitals { get; set; }
public Operator()
{
Hospitals = new List<Hospital>();
}
}
I've got a definition like below and essentially, I want to create this in the EmailAccount class:
public EmailUser? EmailUserAccountInfo {get;set;}
the compiler gives me an error about non-nullable types. My goal is I want to make the EmailUser optional. I'm kind of confused because I can set EmailUserAccountInfo = null directly.
var r = new EmailAccount()
{
EmailUserAccountInfo = null,
Id = 1001
};
public class EmailAccount
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
public EmailUser EmailUserAccountInfo { get; set; }
}
public class EmailUser
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
public EmailAccount EmailAcount { get; set; }
public string EmailAddress { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string ZipCode { get; set; }
public string City { get; set; }
public string State { get; set; }
public int Temperature { get; set; }
public string WeatherString { get; set; }
public ImageDetail ImageOfUser { get; set; }
}
You can do this if you add a foreign key and you mark that nullable:
public class EmailAccount
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
// Foreign key
public int? EmailUserAccountInfoId { get; set; }
// Navigation property
public virtual EmailUser EmailUserAccountInfo { get; set; }
}
See this document about naming conventions for Code-First. (Scroll down to Relationship Convention)