Blog reader Joyesh Mitra recently left a comment to one of my very old posts about SQL SERVER – 2005 Take Off Line or Detach Database, which I have written focusing on taking the database offline. However, I did not include how to bring the offline database to online in that post. The reason I did not write it was that I was thinking it was a very simple script that almost everyone knows. However, it seems to me that there is something I found advanced and that is simple for other people sometime, in this case, I thought simple and is not simple for someone. We all have different expertise and we all try to learn new things, so I do not see any reason as to not write about the script to take the database online.
-- Create Test DB
CREATE DATABASE [myDB] GO
-- Take the Database Offline
ALTER DATABASE [myDB] SET OFFLINE WITH
-- Take the Database Online
ALTER DATABASE [myDB] SET ONLINE
-- Clean up
DROP DATABASE [myDB] GO
Joyesh let me know if this answers your question.
Reference : Pinal Dave (https://blog.sqlauthority.com)