There are a number of good reasons to have a separate file as read-only rather than have a new table in an existing file with restricted privileges.
The 'trick' here is to set up the read-only privilege set and a user account in the external file as you see fit and then use File > File Options > Automatically Log In using.... Then, whenever the file is accessed, whether using 'Open Remote...' or by having another file 'force' the opening, the subsidiary one opens without asking for credentials and with the desired privilege set. (I prefer setting up an account, but you can also use the built-in 'Guest Account' option too.)
I hope you can see that this sets you up for a potential problem should you ever actually need to edit the data in this file. FileMaker has accounted for this by allowing any user to force the authentication dialog box to appear when opening a file if the user is holding down the shift key (option key on Mac) as the file opens. So, you'll want to keep track of at least one account with privileges as well as a account in this 'read only' file.
See the FM Help File under:
Home > Designing and creating databases > Creating a database > Setting file options
Home > Designing and creating databases > Protecting databases > Opening files protected with passwords
I just 'fixed' a client's databases today where they couldn't add/edit records because they had turned this setting on a while back, but didn't remember what they did.
-- Drew Tenenholz
I've put this fix into action but ran into the problem you described. I have db1 and db2. Both have users that access them each directly with Read only or Date Entry privileges. Db1 shows data from db2 but I don’t want db1 users to see db2 in the WebDirect list. (That’s why I need to remove db1 users for the db2 read only privileges). The problem is, once I set a read only auto open account on db2 the db2 Data Entry users loose there SSO capability. Is there any other way around this problem?
Maybe I could duplicate fields in db1 and use ODBC to update changes every 15min? I've never used ODBC before.
FMS13 Windows Server 2008 R2
AD SSO authentication