// schema file for showing relation between host machine and hosted VMs

// Physical machine 
class VMSystem_PhysicalMachine
{
    [Required, Key] string Name;

    // Navigation property to virtual machines
    // Array indicates that this is reference collection 
    [AssociationClass("VMSystem_HostVMRelationship"), ToEnd("HostedVMs")] VMSystem_VirtualMachine ref VMs[];
};

// Virtual machine 
class VMSystem_VirtualMachine
{
    [Required, Key] string MachineName;
    [Required, Key, EmbeddedInstance("EDM_GUID")] string Id;

    string OS;

    // Navigation property pointing to physical machine on which virtual machines are created
    [AssociationClass("VMSystem_HostVMRelationship"), ToEnd("PhysicalMachine")] VMSystem_PhysicalMachine ref PhysicalMachine;

    // Navigation property pointing to System to which Virtual machine belongs
    [AssociationClass("VMSystem_SystemVMRelationship"), ToEnd("System")] VMSystem_System ref System;
};

// System: A logical collection of virtual machines
class VMSystem_System
{
    [Required, Key] string Name;
    [Required, Key, EmbeddedInstance("EDM_GUID")] string Id;

    // Navigation property pointing to Virtual machine in the system
    [AssociationClass("VMSystem_SystemVMRelationship"), ToEnd("VMs")] VMSystem_VirtualMachine ref VMs[];
};

// Association between Physical machine and Virtual machine
// Cardnality is not specified in the association class. It is specified in navigation property
[association] class VMSystem_HostVMRelationship
{
    VMSystem_PhysicalMachine ref PhysicalMachine;
    VMSystem_VirtualMachine ref HostedVMs;
};

// Association between System and Virtual machine
[association] class VMSystem_SystemVMRelationship
{
    VMSystem_System ref System;
    VMSystem_VirtualMachine ref VMs;
};