Hi, I'm going through the web2py tutorial and I don't understand part of this line:
db.comment.image_id.requires = IS_IN_DB(db, db.image.id, '%(title)s') I understand that this requires that the image ID of the image the comment is under should be in the database. However, I don't understand what the '%(title)s' at the end is doing. Can someone explain that? Thanks.
