use Envisage

begin tran
if not exists (select * from sys.all_columns where name like 'ActualCapacityScenarioId' and object_id = OBJECT_ID('Team'))
begin
 alter table [Team] 
 add [ActualCapacityScenarioId] uniqueidentifier NULL
end

if not exists (select * from sys.foreign_keys where name like 'FK_Team_Scenario1' and object_id = OBJECT_ID('Team'))
begin
 ALTER TABLE [dbo].[Team]  WITH CHECK ADD  CONSTRAINT [FK_Team_Scenario1] FOREIGN KEY([ActualCapacityScenarioId])
 REFERENCES [dbo].[Scenario] ([Id])

 ALTER TABLE [dbo].[Team] CHECK CONSTRAINT [FK_Team_Scenario1]
end


commit tran