Option explicit

dim model : set model = ActiveModel ' Current active model
dim column
dim symbol

' Create parent table 
dim parentTable
set parentTable = model.Tables.CreateNew()
parentTable.Name = "Parent"

' Create PK column
set column = parentTable.Columns.CreateNew()
column.Name = "Parent_Id"
column.DataType = "int"
column.Primary = True
column.Displayed = True
set symbol = ActiveDiagram.AttachObject(parentTable) ' Put created table on the current diagram

' Create child table
dim childTable
set childTable = model.Tables.CreateNew()
childTable.Name = "Child"

' Create PK column
set column = childTable.Columns.CreateNew()
column.Name = "Child_Id"
column.DataType = "int"
column.Primary = True
column.Displayed = True

' Create foreign key column
set column = childTable.Columns.CreateNew()
column.Name = "Parent_Id"
column.DataType = "int"
column.Primary = False
column.Mandatory = True
column.Displayed = True

set symbol = ActiveDiagram.AttachObject(childTable) ' Put created table on the current diagram

' Create reference
dim ref : set ref = model.References.CreateNew()
ref.Name = "test_ref"
ref.ParentTable = parentTable
ref.ChildTable = childTable

set symbol = ActiveDiagram.AttachObject(ref) ' Put created table on the current diagram
' Error: after execution of this statement the reference is still unvisible !

set symbol = ActiveDiagram.AttachLinkObject(ref) ' Put created reference on the current diagram.