EGL
can create a simple data access application based on a database
to which you are connected. The resulting application contains data
parts,
logic parts and (optionally) Web pages that are based on one or more
database
tables.
Files created for the application
For each
table
that you select, the EGL Data Access Application wizard creates the
following
parts. You can choose to put these parts into a new project or into
one or
more existing projects.
- Data parts based on the table:
- An
SQLRecord part that represents the table
- DataItem parts that
represents the columns in the table
- Data access
functions that perform operations on the database, such as
adding, retrieving, and deleting records. You can choose to put these
data
access functions in libraries or in services.
Also,
you have the option of creating a Web interface for the
data access application. If you choose to create a Web interface,
the wizard
creates these additional files and parts:
- A set of JSF handler
parts that you later generate into a set of parts
that run under JavaServer Faces
- A set of JSP files that provide
the following Web pages:
- A selection condition page,
which accepts selection criteria from
the user
- A list page, which displays multiple rows,
based on the user's
criteria
- A create detail page, which enables the user
to display or insert
one row
- A detail page, which enables the user to display,
update, or delete
one row
Projects
in the application
Before you begin creating
the application, make two decisions about where the new files and
parts will
go:
- You can put all the new files and parts into one project,
or you can put
the files and parts into different projects, based on the kind of
file and
part. Data parts, logic parts, and JSF handler parts (with the associated
Web pages) can all go into separate projects.
- You can put
files and parts into a new project or into an existing project.
If you choose to put parts into different projects, some can go into
an existing
project and others can go into a new project.
Creating the application
- Click .
- In the New window, expand EGL and
click EGL
Data Access Application.
- Click Next.
- In the Project Name field, either select
an existing
EGL project or type the name of a new project. Later, you will be
able to
fine-tune where the new data parts, logic parts, and Web pages will
go, but
at least one kind of part will go into the project you specify here.
- In the Database Connection list, select
a database
connection. You can create a new one by clicking the New button.
For more information, see Creating an SQL database connection.
After
you have selected a database connection, the tables in the database
schema
are listed in the Table Name list.
- In
the Table Name list, select the check box next
to the tables that you want to include in the data access application.
- If you want to create a Web interface for the application, including
JSF
handler parts and Web pages, select the Generate to EGL
Web project check
box. If you clear this check box, your application will contain logic
parts
and data parts that enable you to access the database, but no JSF
handler
parts or Web pages.
- Click Next.
The
Define the Fields page has a
tab for each table that you selected on the previous page. On this
page, you
select the key fields for each table and which fields you want to
be able
to search.
- Select the key fields for each table in the Choose
key fields list.
If the table already had a key field in the database, that field is
selected
as a key already. You cannot remove a key field that is defined in
the database.
- If you are creating a Web interface, select
the search fields for each
table in the Choose search UI fields list.
The wizard
creates a search page for each table you selected, and that search
page will
have an input field for each field that you select here.
- Click Next.
If
you are creating a Web interface,
you will see the Configure the Fields page. Otherwise, the wizard
skips ahead
to the Define Generation options page.
As in previous steps,
the Configure
the Fields page also has a tab for each table that you selected. On
this page,
you select how the Web pages will display the data.
- Set
the display name for each field in the Modify field display
name list. The value in the Display As column
will be that field's label wherever it appears on a Web page. In EGL
terms,
this value becomes the value of the displayName data
item property.
- Select the fields to show on the search results
page by selecting check
boxes in the Choose summary fields list.
- Click Next.
The
Define project creation options
page has options for the new projects and packages.
- In
the Default package name field, type the name
of the top-level package that will contain the new EGL parts. The
default
value is the name of the database connection.
- Under Data
access method, select whether you want
to create library parts or service parts to hold the new data access
functions.
- If you want to prefix the names of the tables with
the name of the database
schema, select Qualify table names with schema.
This
check box determines whether the EGL code will refer to the database
table
simply by the table name or by the schema name and the table name.
Whether
you select this check box or not depends on how you are connecting
to the
database. For most testing databases, or if you want to create a simple
application
as quickly as possible, you specify the schema name in the EGL code
to avoid
specifying the table name in other places; in this case, select the
check
box. For most production databases, you specify only the table name
in the
EGL code and specify the schema name in a bind step in the JCL; in
this case,
clear the check box.
- If the names of any of the tables
or columns in the database are SQL reserved
words, or if the table or column names include any characters that
are not
valid in ANSI SQL, such as characters from DBCS languages, select
the Use
delimited SQL identifiers check box. If you select this
check
box, the EGL code will use quoted strings for the table and column
names.
- If you want to put all of the new files and parts into
one project, clear
the Create multiple projects check box. All
of the
new files and parts will be created in the project that you entered
in the Project
Name field on a previous page. Then, click Finish.
- If you want to put the new files and parts into different projects,
select
the Create multiple projects check box and
then click Next.
Specify additional options about the projects on the next page.
The
Define
alternate project locations page enables you to select separate projects
to
hold the new data parts, logic parts, and Web interface files and
parts, with
the following restrictions:
- At least one of the projects must
be the same as the project you entered
in the Project Name field on a previous page.
- You cannot put all of the files and parts in the same project.
If you
want to put all of the files in the same project, go back one page
and clear
the Create multiple projects check box.
- For each kind of file or part, choose a project.
- In the Data
Project Name field, select a project
to hold the new data parts.
- In the Data Access
Project Name field, select a
project to hold the new logic parts (services or libraries, depending
on your
choices on the previous page).
- In the UI Project
Name field, select a project
to hold the new Web pages and JSF handler parts.
- For
each project, select the EGL Web Project field
if you want the respective project to be an EGL Web project.
- Click Next.
- The final page of the wizard shows a summary of your choices so
far. You
can click Finish and complete the process or
go back
to previous pages and change your selections.
- After the projects
and files are created, you might need to add the projects
to the EGL and Java™ build paths of other projects.
See EGL build path.