The following is from the filemaker tech brief. http://www.filemaker.com/products/filemaker-go/docs/techbrief_filemaker_go_121_en.pdf
FileMaker Go can access External SQL Sources in databases hosted on FileMaker Server or shared via FileMaker Pro through the use of ESS (External SQL Sources). ESS is supported just as it is with FileMaker Pro using the ODBC driver on the FileMaker Server machine or the FileMaker Pro desktop machine. Databases stored on the mobile device cannot access SQL Sources directly because there is currently no ODBC driver for iOS devices.
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