Is there a way to get the filemaker internal foreignID if using a mysql datasource.

You can use FileMaker as a data source and extract data from it "directly". You need to be using FileMaker Server Advanced.

http://www.filemaker.com/11help/html/odbc.18.1.html

With that said, you may have other options depending on your exact needs. Here are a couple off the top of my head ( I'm sure others can add more ):

• Use FileMaker's ESS ( External SQL Source ) feature to connect FM to the MySQL database, and set the field in MySQL using FileMaker. You could also incorporate into the FM file the 'automatic' set of the field in MySQL whenever a record is created. That way you don't need to manually retrieve the value. Script Triggers or other techniques come in handy here.
  
• Export from FileMaker to a network location that the MySQL database has access to and import.
  

I have the datasource as just mysql. My issue is that when i create a snapshot link and view the file in a text editor the foreign id does not match any off the data in mysql. I was hoping that I could have a calc that could give me the id so that i can generate the snapshot link outside of filemaker

Wow, I totally read that the wrong way. I haven't used the snapshot links too much. I'll test a few things and see if I can duplicate the issue you are seeing.

Okay i have got a bit of a work around. I have created a new table and use Filemaker as its datasource. When I create a new record in MySql via Filemaker I create a record in this new filemaker data table. I can then use the internal row id of the new table to create the snapshot link. this takes me to a layout based on the filemaker data source but that has a script trigger to go to a related record in MySQL

It seems to be working fine.

The only issue is that it opens the snapshot in a new window each time. Is there a way around that?

I guess that I could right a script top close all windows but the current one. Not sure how to do that however