Forms are structures that contain data in Zoho Creator. The form data is stored in a relational database and Deluge provides an easy wrapper called collection variable for accessing these data. The collection variables hold one or more records fetched from a form, based on a given criteria, sort by and range. To access the currently submitted/persisted field values, you can use the Deluge variable named input with syntax input.<fieldname>
<collection var> = formname[<criteria>] sort by <field> range from <x> to <y>;
In the following example, the on add -> on success script is written to fetch specific records from the Book form with Name same as the currently submitted book name in the "Issue Book" form. The record fetched is stored in the collection variable named myBook. You can now access any field in this record, from the myBook collection variable.
//fetch the book row from the 'Book' form
if (count(Book [ID == input.book]) > 0)
myBook = Book [ID == input.book];
//modify the 'Status' of this book to 'Issued'.
myBook.Status = "Issued";