Annotation table/entity contains two different IDs -
id field is the unique primary key generated by your database. The
annotationId field is the ID given to the annotation by WebViewer. These values are stored separately in your database.
annotations resolver requires that both properties be returned. However, many databases may not store the
annotationId can be parsed from the XFDF that is stored in your database.
The server exports a utility to do this:
This utility can be used to write a migration script to add the
annotationId column to your database.
Note: This is a very rough example