Index Notation for Multiple-Value Fields and Periodic Groups

This document describes how you can use the index notation (n:n) to specify how many values of a multiple-value field or how many occurrences of a periodic group are to be output.

The following topics are covered:

Use of Index Notation

With the index notation (n:n) you can specify how many values of a multiple-value field or how many occurrences of a periodic group are to be output.

For example, the field INCOME in the DDM EMPLOYEES is a periodic group which keeps a record of the annual incomes of an employee for each year he/she has been with the company.

These annual incomes are maintained in chronological order. The income of the most recent year is in occurrence 1.

If you wanted to have the annual incomes of an employee for the last three years displayed - that is, occurrences 1 to 3 - you would specify the notation (1:3) after the field name in a DISPLAY or WRITE statement (as shown in the following example program).

Example of Index Notation in DISPLAY Statement 

** Example 'DISPLX07': DISPLAY (with index notation)
************************************************************************
DEFINE DATA LOCAL
1 VIEWEMP VIEW OF EMPLOYEES
  2 PERSONNEL-ID
  2 NAME
  2 BIRTH
  2 INCOME  (1:3)
    3 CURR-CODE
    3 SALARY
    3 BONUS (1:1)
END-DEFINE
*
READ (3) VIEWEMP BY BIRTH
  DISPLAY PERSONNEL-ID NAME INCOME (1:3)
  SKIP 1
END-READ
END

Output of Program DISPLX07:

Note that a DISPLAY statement outputs multiple values of a multiple-value field underneath one another: 

Page      1                                                  04-11-11  14:15:54
 
PERSONNEL         NAME                     INCOME
   ID
                               CURRENCY   ANNUAL     BONUS
                                 CODE     SALARY
--------- -------------------- -------- ---------- ----------
 
30020013  GARRET               UKL            4200          0
                               UKL            4150          0
                                                 0          0
 
30016112  TAILOR               UKL            7450          0
                               UKL            7350          0
                               UKL            6700          0
 
20017600  PIETSCH              USD           22000          0
                               USD           20200          0
                               USD           18700          0

As a WRITE statement displays multiple values horizontally instead of vertically, this may cause a line overflow and a - possibly undesired - line advance.

If you use only a single field within a periodic group (for example, SALARY) instead of the entire periodic group, and if you also insert a slash (/) to cause a line advance (as shown in the following example between NAME and JOB-TITLE), the report format becomes manageable.

Example of Index Notation in WRITE Statement 

** Example 'WRITEX03': WRITE (with index notation)
************************************************************************
DEFINE DATA LOCAL
1 VIEWEMP VIEW OF EMPLOYEES
  2 PERSONNEL-ID
  2 NAME
  2 BIRTH
  2 JOB-TITLE
  2 SALARY (1:3)
END-DEFINE
*
READ (3) VIEWEMP BY BIRTH
  WRITE PERSONNEL-ID NAME / JOB-TITLE SALARY (1:3)
  SKIP 1
END-READ
END

Output of Program WRITEX03: 

Page      1                                                  04-11-11  14:15:55
 
30020013 GARRET
TYPIST                          4200       4150          0
 
30016112 TAILOR
WAREHOUSEMAN                    7450       7350       6700
 
20017600 PIETSCH
SECRETARY                      22000      20200      18700