I am new to entity framework. I have following models.
public partial class PropertyDetail
{
public int PropertyID { get; set; }
public string PropertyName { get; set; }
public virtual PropertyAddress PropertyAddress { get; set; }
public string AnalyticsView { get; set; }
public string MoreInformationLink { get; set; }
}
public class PropertyAddress
{
public string PropertyName { get; set; }
public string StreetAddress { get; set; }
public string PostalCode { get; set; }
public virtual PropertyDetail PropertyDetail { get; set; }
}
I want PropertyID from PropertyDetail to be primary key and PropertyName to be Foreign key in PropertyAddress table.
Thank for help.
with EF6 you can't: the FK must be of the same type as the PK. I heard about that in EF7 but not for sure.
Related
I need to configure multiple foreign key 1:1 relationships in single entity, I have gone through so many posts, Please check below code for your reference. Please help me to configure the same in entity framework.
public class Institution
{
public Institution()
{
InstitutionId = Guid.NewGuid().ToString("N");
}
public string InstitutionId { get; set; }
public string InstutionName { get; set; }
public string BackgroundImage { get; set; }
public string InstitutionCode { get; set; }
public int Logo { get; set; }
public string AddressId { get; set; }
[ForeignKey("AddressId")]
public virtual Address Address { get; set; }
public string ServerId { get; set; }
[ForeignKey("ServerId")]
public virtual Server InstitutionServer { get; set; }
}
Thanks in advance,
I have the following code:
Class
public partial class Emp_Details
{
public long Emp_ID { get; set; }
public string Emp_Title { get; set; }
public string Emp_Name { get; set; }
public string Emp_LastName { get; set; }
public string Emp_Status{ get; set; }
}
entity Code
using (LoginEntities dbcontext = new LoginEntities())
{
Emp_Details emp = dbcontext.Emp_Details.Single(i => i.Emp_ID == empid);
emp.Emp_Status = status;
dbcontext.SaveChanges();
}
I am getting the exception
System.InvalidOperationException: The property 'Emp_Status' is part of the object's key information and cannot be modified.
I have searched for a solution and found 2 possible fixes:
1)Set a primary Key. If there is no primary key on a table, it will simply select the non-nullable columns as a concatenated primary key and the entity will be read/only.
2) Use a direct update such as:
dbcontext.Database.ExecuteSqlCommand(
"UPDATE Emp_Details SET [Emp_Status] = {0} WHERE [Emp_ID] = {1}", status, empid);
Is there any way to do this update without having to touch the database, set primary keys, or mess with the class file?
Your entity doesn't have a primary key. So:
public partial class Emp_Details {
public long Id { get; set; } // pay attention to this
public string Emp_Title { get; set; }
public string Emp_Name { get; set; }
public string Emp_LastName { get; set; }
public string Emp_Status{ get; set; }
}
Or
public partial class Emp_Details {
public long Emp_DetailsId { get; set; } // pay attention to this
public string Emp_Title { get; set; }
public string Emp_Name { get; set; }
public string Emp_LastName { get; set; }
public string Emp_Status{ get; set; }
}
Or
public partial class Emp_Details {
[Key] // pay attention to this
public long Emp_ID { get; set; }
public string Emp_Title { get; set; }
public string Emp_Name { get; set; }
public string Emp_LastName { get; set; }
public string Emp_Status{ get; set; }
}
Each of above changes, will solve the problem.
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 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.
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)