Building an Application with Application Express

You can accomplish a lot on this page. You can specify any number of pages that will be part of your
application with just a few clicks. Since you only have one table available right now, you will only create
one set of pages but with a more fully populated database, you could create fairly sophisticated applica-
t ion systems with the point-and-click methods of this page.
That’s it! You will be presented with the Summary page shown in Figure 2-15, listing the defaults
applied to your application. These defaults include specifying one level of tabs, a standard method of
authenticating users, and a standard template. You can change any of these, or you could have selected
t hem during t he application creation process by clicking Next on the Create Application page shown
in Figure 2-14. You can also access the edit pages for these choices by using the Previous button on
the page.
This page gives you t he option of changing the template for the application, which provides the basic
look and feel for the end user. The examples in this book will use Theme 13. Later in this book, you will
learn more about templates and how to use them.

Building an Application with Application Express

Building an Application with Application Express
1. Log into your APEX-hosted account
2. Click on the Utilities icon, and use the cascading menus to select Data Load/Unload, and thenthe Load choice
3. Click on the Load Spreadsheet Data icon in the Load page, which will bring up the page shown
4. On this page, accept the (Load To) New table choice, but change the Load From choice toUpload File. Click Next once you have made this change.
5. The next page, shown in Figure 2-5, prompts you for the name of the file to use as a data source.
6. Click Browse and locate the ORDERS.csv file. The default values for other choices on this pag can be left with their default values for this file. Click Next to bring up the next page.

You can also see a dropdown box asking for a schema. In Oracle terms, a schema is equivalent to a database
–– a set of tables that can be directly accessed, without further name qualification. You defined a
schema when you created your online account in the last chapter.
The next page, shown in Figure 2-7, has a few choices that control how APEX will implement logic for
this particular table. In relational terms, every row in a table must have a primary key. The primary key
is used to identify the particular row of the table. On this page, you identify either a new or existing
column to hold the primary key value. APEX also asks for the name of a constraint to use to implement
the primary key. A constraint is simply a database specification that indicates, in this case, that the particular
column is a primary key.
Finally, the page asks if you want to use a sequence to generate primary keys. APEX applications
require that each row in a table will have a unique primary key value. The Oracle database includes
an object that is ideal for generating unique values — a sequence, which is roughly equivalent to an
Autonumber data type field in Access. A sequence object performs a simple task––each time you ask
the sequence for a number, the sequence provides the next consecutive number.
The page shown in Figure 2-7 allows you to specify the creation of a new sequence to generate a primary
key, use an existing sequence, or not generate a sequence, which requires you to provide your