HP 3000 Manuals HP 3000 Manuals
Summary
In this lesson you used the SCROLL command to display data in the scroll
area of a screen.
For KSAM based and HP TurboIMAGE/iX based applications, this lesson also
introduced the FILE *FIND command. The FILE *FIND command searches a
file for a record with a key equal to or greater than a specified value.
You can then use the FILE *NEXT command to retrieve the record.
You also associated a secondary record layout with a data file. This
enables the application to read and use two different records from the
same data file.
For HP ALLBASE/SQL based applications, this lesson introduced SQL select
lists.
You used a select list to retrieve data from an HP ALLBASE/SQL base
table. Using a select list allows you to declare and open an additional
cursor without changing any existing cursors.
In this application, the optscrol select list allows you to retrieve
information from option records for a product, without changing the
existing cursor used to retrieve the current option record that may be
displayed on the option window.
Select lists have the following characteristics:
* A select list is a "virtual" file. You can reference fields on a
select list as though they are file record fields.
* A select list definition consists of the select list header, and
the select list details.
* Each entry in a select list has the format:
field_spec [= column_definition],
Columns can be derived directly from columns of existing tables or
views, or can be derived using SQL expressions.
To simplify the procedure for defining a select list, you can omit
the right hand side of each entry if the column definition is
exactly the same as the field specification name.
* A select list must be generated. When HP ALLBASE/4GL generates a
select list, it creates a generated record layout using the field
specifications on the left hand side of the select list entries.
Before you move onto the next chapter, you will be introduced to user
help screens.