if not exists (select * from sys.syscolumns where name = 'Expiration' and id = object_id(N'dbo.ConnectionHistory'))
    alter table dbo.ConnectionHistory
    add Department nvarchar(256) null
        ,IsSubConnection bit null
        ,IsTemplate bit null
        ,Groups nvarchar(256) null
        ,DescriptionRTF nvarchar(max) null
        ,ConnectionMasterSubType varchar(64) null
        ,UrlLink nvarchar(256) null
        ,Keywords nvarchar(max) null
        ,SortPriority int null
        ,Status varchar(64) null
        ,StatusMessage nvarchar(256) null
        ,Image varbinary(max) null
        ,Category nvarchar(250) null
        ,Expiration datetime null