Mahmoud AlSaadi brings us a new GP 2013 R2 Attachments Report. A lot of people have asked me where the attachments are stored and after using Mahmoud’s report as a starting point, it appears that they are stored in table named coAttachmentItems.
Dynamics GP Essentials: Attachments Report
Reporting & BISQL & DataDevelopment & IntegrationGP 2013
Archived post from 2014. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.