if not exists (select * FROM sys.syscolumns where name = 'ConnectionOverrides' AND id = object_id(N'dbo.UserInfo')) 
  alter table dbo.UserInfo ADD ConnectionOverrides nvarchar(max) NULL;

if not exists (select * FROM sys.syscolumns where name = 'CustomSecurity' AND id = object_id(N'dbo.UserInfo')) 
  alter table dbo.UserInfo ADD CustomSecurity nvarchar(max) NULL;