C#•7mo ago

Entity Framework Core One-to-One Relationship => Introducing FOREIGN KEY constraint

public class TaskEmployee
    {
        public int TaskEmployeeId { get; set; }
        public string Title { get; set; }
        public Shop Shop { get; set; }
        public Employee Employee { get; set; }
    }

public class TaskEmployee
    {
        public int TaskEmployeeId { get; set; }
        public string Title { get; set; }
        public Shop Shop { get; set; }
        public Employee Employee { get; set; }
    }

and

public class Shop
    {
        [Required]
        public int ShopId { get; set; }
        public string Name { get; set; }
        public Address? Address { get; set; }
        public int TaskEmployeeeId { get; set; }
        public TaskEmployee TaskEmployee { get; set; }
    }

public class Shop
    {
        [Required]
        public int ShopId { get; set; }
        public string Name { get; set; }
        public Address? Address { get; set; }
        public int TaskEmployeeeId { get; set; }
        public TaskEmployee TaskEmployee { get; set; }
    }

and

public class Employee
    {
        [Required]
        public int EmployeeId { get; set; }
        public string FirstName { get; set; }
        public EmployeePosition EmployeePosition { get; set; }
        [ForeignKey("ShopId")]
        public int ShopId { get; set; }
        public Shop Shop { get; set; }
        public int TaskEmployeeeId { get; set; }
        public TaskEmployee TaskEmployee { get; set; }
    }

public class Employee
    {
        [Required]
        public int EmployeeId { get; set; }
        public string FirstName { get; set; }
        public EmployeePosition EmployeePosition { get; set; }
        [ForeignKey("ShopId")]
        public int ShopId { get; set; }
        public Shop Shop { get; set; }
        public int TaskEmployeeeId { get; set; }
        public TaskEmployee TaskEmployee { get; set; }
    }

So I want relations that TaskEmployee has one Shop and one Employee and in DataContext I have this:

public  modelBuilder.Entity<TaskEmployee>()
                .HasOne(h => h.Employee)
                .WithOne(h => h.TaskEmployee)
                .HasForeignKey<Employee>(h => h.EmployeeId);

            modelBuilder.Entity<TaskEmployee>()
                .HasOne(h => h.Shop)
                .WithOne(h => h.TaskEmployee)
                .HasForeignKey<Shop>(h => h.ShopId);

public  modelBuilder.Entity<TaskEmployee>()
                .HasOne(h => h.Employee)
                .WithOne(h => h.TaskEmployee)
                .HasForeignKey<Employee>(h => h.EmployeeId);

            modelBuilder.Entity<TaskEmployee>()
                .HasOne(h => h.Shop)
                .WithOne(h => h.TaskEmployee)
                .HasForeignKey<Shop>(h => h.ShopId);

and error during update database: Introducing FOREIGN KEY constraint 'FK_TaskEmployees_Shops_TaskEmployeeId' on table 'TaskEmployees' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint or index. See previous errors.

5 Replies

Anu6is•7mo ago

public class Employee
    {
        [Required]
        public int EmployeeId { get; set; }
        public string FirstName { get; set; }
        public EmployeePosition EmployeePosition { get; set; }
        [ForeignKey("ShopId")]
        public int ShopId { get; set; }
        public Shop Shop { get; set; }
        public int TaskEmployeeeId { get; set; }
        public TaskEmployee TaskEmployee { get; set; }
    }

public class Employee
    {
        [Required]
        public int EmployeeId { get; set; }
        public string FirstName { get; set; }
        public EmployeePosition EmployeePosition { get; set; }
        [ForeignKey("ShopId")]
        public int ShopId { get; set; }
        public Shop Shop { get; set; }
        public int TaskEmployeeeId { get; set; }
        public TaskEmployee TaskEmployee { get; set; }
    }

why are you adding a foreign key to the shop here?

fright•7mo ago

relations one-to-many Shop with many Employee modelBuilder.Entity<Employee>() .HasOne(h => h.Shop) .WithMany(h => h.Employees) .HasForeignKey(h => h.ShopId) .IsRequired(); I remeber that I had problem also with this any suggestion ? 😦

Anu6is•7mo ago

what do you actually want as the end goal? a shop has many employees an employee has one shop and the employee has one task?

fright•7mo ago

I want TaskEmployee has one Shop and one Employe

Anu6is•7mo ago

public class Shop
{
    public int ShopId { get; set; }
    public string Name { get; set; }
    public Address? Address { get; set; }

    // Navigation property for one-to-many relationship
    public List<Employee> Employees { get; set; }
}

public class Employee
{
    public int EmployeeId { get; set; }
    public string FirstName { get; set; }
    public EmployeePosition EmployeePosition { get; set; }

    // Foreign key property for the many-to-one relationship with Shop
    public int ShopId { get; set; }

    // Navigation property for the many-to-one relationship with Shop
    public Shop Shop { get; set; }

    // Navigation property for the one-to-one relationship with TaskEmployee
    public TaskEmployee TaskEmployee { get; set; }
}

public class TaskEmployee
{
    public int TaskEmployeeId { get; set; }
    public string Title { get; set; }

    // Foreign key property for the one-to-one relationship with Employee
    public int EmployeeId { get; set; }

    // Foreign key property for the one-to-one relationship with Shop
    public int ShopId { get; set; }

    // Navigation properties
    public Employee Employee { get; set; }
    public Shop Shop { get; set; }
}

// Your DbContext class
        modelBuilder.Entity<Employee>()
            .HasOne(e => e.Shop)
            .WithMany(s => s.Employees)
            .HasForeignKey(e => e.ShopId);

        modelBuilder.Entity<TaskEmployee>()
            .HasOne(te => te.Employee)
            .WithOne(e => e.TaskEmployee)
            .HasForeignKey<TaskEmployee>(te => te.EmployeeId);

        modelBuilder.Entity<TaskEmployee>()
            .HasOne(te => te.Shop)
            .WithOne(s => s.TaskEmployee)
            .HasForeignKey<TaskEmployee>(te => te.ShopId);

public class Shop
{
    public int ShopId { get; set; }
    public string Name { get; set; }
    public Address? Address { get; set; }

    // Navigation property for one-to-many relationship
    public List<Employee> Employees { get; set; }
}

public class Employee
{
    public int EmployeeId { get; set; }
    public string FirstName { get; set; }
    public EmployeePosition EmployeePosition { get; set; }

    // Foreign key property for the many-to-one relationship with Shop
    public int ShopId { get; set; }

    // Navigation property for the many-to-one relationship with Shop
    public Shop Shop { get; set; }

    // Navigation property for the one-to-one relationship with TaskEmployee
    public TaskEmployee TaskEmployee { get; set; }
}

public class TaskEmployee
{
    public int TaskEmployeeId { get; set; }
    public string Title { get; set; }

    // Foreign key property for the one-to-one relationship with Employee
    public int EmployeeId { get; set; }

    // Foreign key property for the one-to-one relationship with Shop
    public int ShopId { get; set; }

    // Navigation properties
    public Employee Employee { get; set; }
    public Shop Shop { get; set; }
}

// Your DbContext class
        modelBuilder.Entity<Employee>()
            .HasOne(e => e.Shop)
            .WithMany(s => s.Employees)
            .HasForeignKey(e => e.ShopId);

        modelBuilder.Entity<TaskEmployee>()
            .HasOne(te => te.Employee)
            .WithOne(e => e.TaskEmployee)
            .HasForeignKey<TaskEmployee>(te => te.EmployeeId);

        modelBuilder.Entity<TaskEmployee>()
            .HasOne(te => te.Shop)
            .WithOne(s => s.TaskEmployee)
            .HasForeignKey<TaskEmployee>(te => te.ShopId);

not 100% sure but something like that maybe ... i still don't thing you need to explicitly define TaskEmployee has one Shop and one Employee

public class Shop
{
    public int ShopId { get; set; }
    public string Name { get; set; }
    public Address? Address { get; set; }

    // Navigation property for one-to-many relationship
    public List<Employee> Employees { get; set; }
}

public class Employee
{
    public int EmployeeId { get; set; }
    public string FirstName { get; set; }
    public EmployeePosition EmployeePosition { get; set; }

    // Foreign key property
    public int ShopId { get; set; }

    // Navigation property for the many-to-one relationship with Shop
    public Shop Shop { get; set; }

    // Navigation property for the one-to-one relationship with Task
    public TaskEmployee TaskEmployee { get; set; }
}

public class TaskEmployee
{
    public int TaskEmployeeId { get; set; }
    public string Title { get; set; }

    // Foreign key property
    public int EmployeeId { get; set; }

    // Navigation property for the one-to-one relationship with Employee
    public Employee Employee { get; set; }
}

modelBuilder.Entity<Employee>()
    .HasOne(e => e.Shop)
    .WithMany(s => s.Employees)
    .HasForeignKey(e => e.ShopId);

modelBuilder.Entity<TaskEmployee>()
    .HasOne(te => te.Employee)
    .WithOne(e => e.TaskEmployee)
    .HasForeignKey<TaskEmployee>(te => te.EmployeeId);

public class Shop
{
    public int ShopId { get; set; }
    public string Name { get; set; }
    public Address? Address { get; set; }

    // Navigation property for one-to-many relationship
    public List<Employee> Employees { get; set; }
}

public class Employee
{
    public int EmployeeId { get; set; }
    public string FirstName { get; set; }
    public EmployeePosition EmployeePosition { get; set; }

    // Foreign key property
    public int ShopId { get; set; }

    // Navigation property for the many-to-one relationship with Shop
    public Shop Shop { get; set; }

    // Navigation property for the one-to-one relationship with Task
    public TaskEmployee TaskEmployee { get; set; }
}

public class TaskEmployee
{
    public int TaskEmployeeId { get; set; }
    public string Title { get; set; }

    // Foreign key property
    public int EmployeeId { get; set; }

    // Navigation property for the one-to-one relationship with Employee
    public Employee Employee { get; set; }
}

modelBuilder.Entity<Employee>()
    .HasOne(e => e.Shop)
    .WithMany(s => s.Employees)
    .HasForeignKey(e => e.ShopId);

modelBuilder.Entity<TaskEmployee>()
    .HasOne(te => te.Employee)
    .WithOne(e => e.TaskEmployee)
    .HasForeignKey<TaskEmployee>(te => te.EmployeeId);

I feel like this would have worked without the explicit taskemployee to shop link, since the employee is already linked to the shop

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Entity Framework Core One-to-One Relationship => Introducing FOREIGN KEY constraint