Compaq COBOL AAQ2G1FTK - Manual (Page 141)

Handling Tables
4.3 Accessing Table Elements
A useful variation of the binary search is that of specifying multiple search
keys. Multiple search keys allow you to select a specified table element from
among several elements that have duplicate low-order keys. An example is
a telephone listing where several people have the same last and first names,
but different middle initials. All specified keys must be either ascending or
descending. Example 4–24 shows how to use multiple search keys.
The table in Example 4–18 is followed by several examples (Examples 4–19, 4–20,
4–21, 4–22, and 4–23) of how to search it.
Example 4–18 Sample Table
DATA DIVISION.
WORKING-STORAGE SECTION.
01
TEMP-IND USAGE IS INDEX.
01 FED-TAX-TABLES.
02
ALLOWANCE-DATA.
03
FILLER PIC X(70) VALUE
"0101440
- "0202880
- "0304320
- "0405760
- "0507200
- "0608640
- "0710080
- "0811520
- "0912960
- "1014400".
02 ALLOWANCE-TABLE REDEFINES ALLOWANCE-DATA.
03
FED-ALLOWANCES OCCURS 10 TIMES
ASCENDING KEY IS ALLOWANCE-NUMBER
INDEXED BY IND-1.
04
ALLOWANCE-NUMBER PIC XX.
04 ALLOWANCE PIC 99999.
02 SINGLES-DEDUCTION-DATA.
03 FILLER PIC X(112) VALUE
"0250006700000016
- "0670011500067220
- "1150018300163223
- "1830024000319621
- "2400027900439326
- "2790034600540730
- "3460099999741736".
02 SINGLE-DEDUCTION-TABLE REDEFINES SINGLES-DEDUCTION-DATA.
03
SINGLES-TABLE OCCURS 7 TIMES
ASCENDING KEY IS S-MIN-RANGE S-MAX-RANGE
INDEXED BY IND-2, TEMP-INDEX.
04
S-MIN-RANGE PIC 99999.
04 S-MAX-RANGE PIC 99999.
04 S-TAX PIC 9999.
04 S-PERCENT PIC V99.
(continued on next page)
Handling Tables 4–19