Nested Actions

Type

Concept

Purpose

A Nested Action is an action that is invoked by another action.

There are two types of nested actions: (1) A nested loop action performs the same series of actions on each record that is processed (see Example 1), and (2) a nested conditional action is most often used to select subgroups of records and perform different actions on each group (see Example 2).

Example 1

for MEMBERS ;

for RESERVATIONS

list records

MEMBERS LASTNAME in groups ;

RESERVATION ID ;

TOTAL DUE .

end

end

This script tells DataEase to perform the same series of actions on each record selected by the for command. In this example, the second for command, which retrieves the RESERVATIONS records related to the MEMBERS record that is currently being processed, is nested within the first for command.

Although DataEase does not require it, it is easier to follow the logic if you indent nested actions as shown in these examples.

Example 2

for RESERVATIONS ;

if TOTAL DUE > 2000 then

modify records in MEMBERS

STATUS := PREFERRED .

if DATE between 01/01/99 to current date then

enter a record in CATALOG MEMBERS

copy all from MEMBERS .

end

end

end

This script tells DataEase to select two groups of RESERVATIONS records: (1)All the records with an TOTAL DUE greater than $2000 (the related MEMBERS records get modified), and (2) the records with an TOTAL DUE greater than $2000 and a DATE between the start of 1994 and today's date (the related MEMBERS records get modified and copied into the CATALOG MEMBERS table).

In this example, the second if command, which selects a subgroup of the records selected by the first if command, is nested within the first if command.