Accessing another DB's Table in a Shadow

[jds.activstyle]

Hello,

I thought I was finally getting to a point to roll out an application I've been working on for some time, and as I created a shadow copy of the DB, I found that the reference I have to another database's table did not propagate over. I'm kind of at a loss on how to continue from here.

Initially, I did want to set my connection to the other database as a passive link table, which I assume would have shown through the shadow, but I am simply guessing as I could see no way to passively link other a5 DBs.

My question is: Is there a way I can reference another database's tables in a shadow of a database, or will I need to consolidate my application into the original DB which hosts key information?

Thanks for your help,
- JDS

[Ray in Capetown]

Re: Accessing another DB's Table in a Shadow

How is the reference to the other db table structured ?
IOW what is the code of the table reference.

[Finian Lennon]

Re: Accessing another DB's Table in a Shadow

With the caveat that it's generally a bad idea to include external databases in an application, consider the following:

1. You can always "open" a table or layout (form, browse, report) in an external location by passing the full path of the table or data dictionary to the open command. So, if you are using an external table in a script you can say

t = table.open(full_path + tablename)

and the table will be opened whether or not it is part of the database. So, theoretically you could use absolute references throughout your code to manipulate the external table.

2. It's probably easier if you do make the external table part of the (shadow) database since that should make it unnecessary to use path references in your code.

To do this, put the following code in the autoexec script of your application

dim global app_path as c = ""
dim this_path as c = A5.Get_Path()
dim shadowed as l = .F.
dim bare_path as C = a5.Get_Master_Path()
if len(alltrim(bare_path)) = 0 			then 'the database is not shadowed
	shadowed = .F.
		app_path = this_path + Chr(92)
			else
				shadowed = .T.		'only returns true when started from the shadow folder,
				app_path = bare_path + chr(92)
end if

if shadowed then
	dim remotefile as c = "C:\Data\Nav Data\Nav60024\a_app_alert.dbf"
	if file.exists(remotefile) then
		file_add_to_db(remotefile)
	end if
end if

The purpose of this code is to establish the path to the application adb and put that value into the global app_path regardless of whether or not the application is shadowed. (This is a personal preference, I then use the variable app_path throughout the application.) In the example, if the application is determined to be shadowed, then the remote file is added to the shadow database. Obviously you would use different path/names.)

For this to work, all the files must be accessible in both shadowed and non-shadowed mode. If installing on a remote machine, you have to make sure that all the required paths are created and files installed so that the app will run.

You mention passive tables and I don't know if they behave in exactly the same way as a regular table as far as adding and dropping from a database is concerned. If they don't then you'll need another way!

[jds.activstyle]

Re: Accessing another DB's Table in a Shadow

Finian,

Thank you very much. I followed option two, as it seemed cleaner to me; this allows me to access the table from a shadow DB exactly as intended. You've been a great help.

- JDS