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,
Related
Am Trying to create Two Tables like bellow got some EF error.
public class Student : ModelsBase
{
public string AdharNumber { get; set; }
public byte Religion { get; set; }
public int CategoryID { get; set; }
public string Cast { get; set; }
public string SubCast { get; set; }
public string Photo { get; set; }
public DateTime DateOfJoining { get; set; } = DateTime.Now;
[Required]
public ICollection<Address> TemporaryAddress { get; set; }
[Required]
public ICollection<Address> PermanentAddress { get; set; }
}
public class Address : ModelsBase
{
public string DoorNo { get; set; }
public string StreetLocality { get; set; }
public string Landmark { get; set; }
public string City { get; set; }
public int Taluk { get; set; }
public int District { get; set; }
public int State { get; set; }
public string Pincode { get; set; }
public bool IsPermanent { get; set; } = true;
public bool IsDefault { get; set; } = true;
[ForeignKey("Student")]
public Guid StudentId { get; set; }
}
Getting the bellow error while trying to Run the "Add-Migration command"
Both relationships between 'Address' and 'Student.PermanentAddress' and between 'Address' and 'Student.TemporaryAddress' could use {'StudentId'} as the foreign key. To resolve this, configure the foreign key properties explicitly in 'OnModelCreating' on at least one of the relationships
Please help. Thanks!
Your issue is that from the Address side of things you have a Many-to-1 with a single Student, but from the Student side of things you want 2x 1-to-Many relationships.
Since The relationship is really just a 1-to-Many from the student that you want to discriminate between temporary and permanent addresses:
public class Student : ModelsBase
{
public string AdharNumber { get; set; }
public byte Religion { get; set; }
public int CategoryID { get; set; }
public string Cast { get; set; }
public string SubCast { get; set; }
public string Photo { get; set; }
public DateTime DateOfJoining { get; set; } = DateTime.Now;
[Required]
public ICollection<Address> Addresses { get; set; } = new List<Address>();
[NotMapped]
public ICollection<Address> TemporaryAddresses => Addresses.Where(x => !x.IsPermanent).ToList();
[NotMapped]
public ICollection<Address> PermanentAddresses => Addresses.Where(x => x.IsPermanent).ToList();
}
With 1-to-many collections I recommend initializing them to an empty list to avoid null reference exceptions especially if lazy loading is disabled.
The caveat here is that from EF's perspective, Student only has the Addresses collection, do not attempt to use either TemporaryAddresses or PermanentAddresses in a query expression as these are unmapped accessors. If you want to filter based on a permanent address you will have to do it through Addresses and include the condition on IsPermanent in the query.
For example:
// Not valid...
var studentsInDetroit = context.Students.Where(x => x.PermanentAddresses.Any(a => a.City == "Detroit")).ToList();
// Valid...
var studentsInDetroit = context.Students.Where(x => x.Addresses.Any(a => a.IsPermanent && a.City == "Detroit")).ToList();
Normally I don't recommend using unmapped accessors in entities because of this. It is generally better to leave entities representing pure domain/data state and project that down to view models which can be more concerned about splitting the data into a more palatable form for consumption.
in my project (Asp.net Core Web Api) I have the tables "Truck" and "UserAccount with a one to many relashionship.
[Table("UserAccount")]
public class UserAccount : BaseClass
{
// Foreign Keys
[ForeignKey(nameof(UserAccountType))]
public int UserAccountTypeId { get; set; }
[ForeignKey(nameof(Gender))]
public int GenderId { get; set; }
[ForeignKey(nameof(Truck))]
public int TruckId { get; set; }
// Properties
public string LastName { get; set; }
public string FirstName { get; set; }
public string UserName { get; set; }
[DataType(DataType.EmailAddress)]
public string Mail { get; set; }
public string Login { get; set; }
[DataType(DataType.Password)]
public string Password { get; set; }
// Navigation Properties
[IgnoreDataMember]
public virtual Gender Gender { get; set; }
//public virtual Truck Truck { get; set; }
[IgnoreDataMember]
public virtual UserAccountType UserAccountType { get; set; }
public Truck Truck { get; set; }
}
[Table("Truck")]
public class Truck : BaseClass
{
// Foreign Keys
// Properties
[Column(Order = 3)]
public string Name { get; set; }
[DataType(DataType.EmailAddress)]
[Column(Order = 4)]
public string Mail { get; set; }
[Column(Order = 5)]
public string Phone { get; set; }
[Column(Order = 6)]
public string VATNumber { get; set; }
// Navigation Properties
public virtual ICollection<TruckFoodType> TruckFoodTypes { get; set; }
public virtual ICollection<TruckOption> TruckOptions { get; set; }
public ICollection<UserAccount> UserAccounts { get; set; }
}
In the method OnModelCreation into my ApplicationDbContex file I have this to create the one to many relashionship:
modelBuilder.Entity<UserAccount>()
.HasOne<Truck>(u => u.Truck)
.WithMany(t => t.UserAccounts)
.HasForeignKey(u => u.TruckId);
But when I try to populate the UserAccount table I have this error message :
"Merge instruction is in conflict with "FK_User_Account_TruckId". This conflict occurse in the database xxx table dbo.Truck column Id" (Sorry, Comes from a french translation)
I don't hunderstand why.
Can somebody help me?
Thanks
OK, stupid mistake. In some cases the TruckId field from the User Account table can be null. So I added a "?" to this fields like this : public int? TruckId { get; set; } Sorry for inconvenience
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.
I use EF's code first approach. I have the following three classes:
public class Inquiry
{
public Guid Id { get; set; }
public string Title { get; set; }
public string Description { get; set; }
public virtual ApplicationUser CreatedBy { get; set; }
public virtual Contractor Contractor { get; set; }
public IList<ApplicationUser> InquiryUsers { get; set; }
public IList<InquiryComment> Comments { get; set; }
public IList<HydroTechEmail> Emails { get; set; }
public InquiryState State { get; set; }
public List<string> Attachments { get; set; }
public DateTime? TimeOfCreation { get; set; }
public DateTime? TimeOfModification { get; set; }
}
public class HydroTechEmail
{
public Guid Id { get; set; }
public string Subject { get; set; }
public string Content { get; set; }
public string FromDisplayName { get; set; }
public string FromAddress { get; set; }
public List<string> ToDisplayName { get; set; }
public List<string> ToAddress { get; set; }
public HydroTechEmailState State { get; set; }
public DateTime? ReceivedTime { get; set; }
public virtual List<HydroTechEmailAttachment> Attachments { get; set; }
public virtual ApplicationUser ApplicationUser { get; set; }
}
public class ApplicationUser
{
public Guid Id {get;set;}
public string Firstname {get;set;}
public string Lastname {get;set;}
}
I thought EF will generate some intermediate classes for relation Inquiry -> Many Emails and Inquiry -> Many Application Users. Instead it created a foreign keys in ApplicationUser and HydroTechEmail classes to Inquiry class. How should I create this one to many relations?
The strange is that for Comments it created an intermediate table named InquiryComments.
Entity Framework will only generate intermediate tables for many-to-many relationships.
For one-to-many relationships, no intermediate tables will be created because it is not necessary.
My issue is the following. I have a Model for an Address table as follows.
public partial class ADDRESS
{
public ADDRESS()
{
this.ADDRESS_ID = Guid.NewGuid();
}
public Guid ADDRESS_ID { get; set; }
public string ADDRESS_LINE { get; set; }
public string CITY { get; set; }
public Guid? STATE_ID { get; set; }
public string ZIP { get; set; }
}
This ADDRESS model is used throughout my application and has different validation requirements depending on where it is placed within a form.
I am wondering if there is a way to customize the data annotations. For example, the ADDRESS_LINE and CITY properties are required for OCCUPATION_ADDRESS but not required for WORK_LOCATION_ADDRESS.
public class OCCUPATION_DETAILS
{
public string COMPANY_NAME { get; set; }
public string JOB_TITLE { get; set; }
etc...
public Guid OCCUPATION_ADDRESS_ID { get; set; }
public virtual ADDRESS OCCUPATION_ADDRESS { get; set; }
public WORK_LOCATION_ID { get; set; }
public virtual ADDRESS WORK_LOCATION_ADDRESS { get; set; }
}
Or it could be that basic validation is the same (zip has to be 5 digits), but I need to adjust the "DisplayName" that is used to match the label of the form it is within.
Trying to minimize the amount of copied models I have set up; otherwise maintenance will be a nightmare.
you can achieve this by using the idea of inheritance
how?
public abstract class ADDRESS
{
public ADDRESS()
{
this.ADDRESS_ID = Guid.NewGuid();
}
public Guid ADDRESS_ID { get; set; }
public string ADDRESS_LINE { get; set; }
public string CITY { get; set; }
public Guid? STATE_ID { get; set; }
public string ZIP { get; set; }
}
public parital class OCCUPATION_ADDRESS: ADDRESS,IValidatableObject
{
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
if(string.IsNullOrWhiteSpace(ADDRESS_LINE))
yield return new ValidationResult("Address line is required!",new string[]{"ADDRESS_LINE"});
}
}
public parital class WORK_LOCATION_ADDRESS: ADDRESS,IValidatableObject
{
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
}
}
// and your Occupation details class will be like: instead of ADDRESS you will use the corresponding derived classes
public class OCCUPATION_DETAILS
{
public string COMPANY_NAME { get; set; }
public string JOB_TITLE { get; set; }
etc...
public Guid OCCUPATION_ADDRESS_ID { get; set; }
public virtual OCCUPATION_ADDRESS OCCUPATION_ADDRESS { get; set; }
public WORK_LOCATION_ID { get; set; }
public virtual WORK_LOCATION_ADDRESS WORK_LOCATION_ADDRESS { get; set; }
}
and the inheritance should be Table per Hierarchy (TPH)
for more information about TPH check this Table per hierarchy
hope that this will help you
regards