if not exists (select * from sys.indexes where name = 'CI_ConnectionLog_StartDateTimeUTC' and object_id = object_id(N'dbo.ConnectionLog'))
    and exists (select * from sys.default_constraints where object_id = OBJECT_ID(N'DF_ConnectionLog_IsPrivate') AND parent_object_id = OBJECT_ID(N'dbo.ConnectionLog '))
    alter table dbo.ConnectionLog drop constraint DF_ConnectionLog_IsPrivate