Foreign key error

[aydinbskr]

At some tables, the system not add inner join

[Mike6x]

Same issue:

I have class as belowing.

• When I create a employee with DepartmentId & SubDepartmentId != null => Sucessfully !
• When I create a employee with DepartmentId != null & SubDepartmentId = null => Failed with error:

(0x80131904): The INSERT statement conflicted with the FOREIGN KEY constraint "FK_Employees_SubDepartments_SubDepartmentId".
The conflict occurred in database "rootTenantDb", table "SubDepartments", column 'Id'.

How to fix or work around it ???

public class Employee : AuditableEntity, IAggregateRoot
{
public string FirstName { get; private set; }
public string? LastName { get; private set;
.....
public DefaultIdType DepartmentId { get; private set; }
public virtual Department Department { get; private set; } = default!;

public DefaultIdType? SubDepartmentId { get; private set; }
public virtual SubDepartment SubDepartment { get; private set; } = default!;
}

public class SubDepartment : AuditableEntity, IAggregateRoot
{
public string Name { get; private set; } = default!;
public string Description { get; private set; } = string.Empty;

public DefaultIdType DepartmentId { get; private set; }
public virtual Department Department { get; private set; } = default!;
}

public class Department : AuditableEntity, IAggregateRoot
{

public string Name { get; private set; } = default!;
public string Description { get; private set; } = string.Empty;
}