Forms and Reports—The Basics - Beginning Oracle Application Express 4.2 - page 138

Figure 6-17. Elements of a form as viewed from Application Builder
The Page Rendering region contains APEX objects required for page rendering. The
Page Processing region contains objects required for page processing, such as valida-
tions, processes, and branches. The Shared Components region contains APEX objects
that are shared across pages, such as tabs, lists of values, breadcrumbs, templates, and
security schemes.
For your new Create a Ticket form, in the Page Rendering section, you see that the
wizard has created one item for each of the columns from the TICKETS table that you
selected via the wizard. There are also two buttons called Cancel and Create, and a
Fetch Row from TICKETS process. This process is an Automated Row Fetch process,
which does exactly what its name says: it fetches a row from the designated table into
the current form. The attributes of the Automated Row Fetch process specify the table
owner, the table name, the primary key column(s), success and failure messages, and a
condition.
Notice that the TICKET_ID item is present on the page but isn't rendered on the
form. It's visible in the Display Details view of the form as the first element on the
page, with no visible element associated with it. TICKET_ID is a hidden item. APEX
hidden items exist to hold a value, but although they're rendered on the page, they
aren't visible to the user. In this case, the hidden TICKET_ID column holds the
primary key value for the TICKETS row. As the primary key, TICKET_ID is used by
the APEX processes to pull data from the database and to process inserts, updates, and