Procedure |
Virtual Machine |
 |
In order to define one or more alternate keys for a file use the following procedure.
1. At PROIV File Maintenance define the physical record layout in the usual way, and then for the first alternate key continue as follows.
2. Mark the beginning of the alternate key definition by defining the next entry as a Mapped Start entry by giving it a DATA TYPE of MS and VARIABLE NAME of filename. Press <Return> only, at the remaining fields for this record.
3. In the next VARIABLE NAME field, enter a full or partial variable name to make up the whole or a part of the alternate key. Press <Return> only, at the remaining fields for this record.
4. Variables used in alternate keys must be of DATA TYPE 'A' and EXTERNAL TYPE 'ALPHA'.
5. Repeat step 3 for any remaining parts of the alternate key in order.
6. Mark the end of the alternate key definition by defining the next record as a Mapped End record ME. Press <Return> only, at the remaining fields for this record.
7. If more than one alternate key is to be defined, repeat steps 2 to 5 for each one.
8. End the file definition in the usual way.
Example
This example shows how to access a CUSTOMER file by each of three alternate keys, the first two of which have duplicates and so cannot be used where an individual record is to be accessed uniquely by key. The first screen shows the CUSTOMER file definition (which includes the alternate key definitions) and the remaining screens show typical examples of the alternate keys' usage.
PTI @DOCFIL PROIV Technologies 12/06/91 14:20 PAGE 1
TRM: CONSOLE F I L E D O C U M E N T A T I O N OPR: SYS
CO- AUTO- EXTERNAL FILE KEY RECORD
DIV SEQUENCED RECORD FORMAT TYPE LENGTH LENGTH
FILE NAME: CUSTOMER Y 10 109
ALTERNATE: RECORD CODE:
DESC: CUSTOMER MASTER FILE
-------------------------------R E C O R D L A Y O U T---------------------------------
DATA MAX FILL SPECIAL ARRAY
SEQ TYPE VARIABLE NAME LEN CODE DISPLAY-CODE CHECK SIZE
--- ---- ----------------------------------- --- ---- ------------ ------- -----
001 K CUST.NO 10
EXTERNAL TYPE ALPHA STORAGE FORMAT ENCRYPTED
002 A CUST_NAME 30
EXTERNAL TYPE ALPHA STORAGE FORMAT ENCRYPTED
003 A CUST_ADDR 30
EXTERNAL TYPE ALPHA STORAGE FORMAT ENCRYPTED
004 A CUST_CITY 25
EXTERNAL TYPE ALPHA STORAGE FORMAT ENCRYPTED
005 A CUST_STATE 2
EXTERNAL TYPE ALPHA STORAGE FORMAT ENCRYPTED
006 A CUST_POST 9
EXTERNAL TYPE ALPHA STORAGE FORMAT ENCRYPTED
007 A CUST_SLSMN 3
EXTERNAL TYPE ALPHA STORAGE FORMAT ENCRYPTED
008 MS SLSCUST
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
009 M CUST_SLSMN 1 3
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
010 ME
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
011 MS POSTCUST
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
012 M CUST_POST 1 5
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
013 M CUST_NAME 1 10
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
014 ME
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
015 MS POSTCUSU
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
016 M CUST_POST 1 9
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
017 M CUST.NO 1 10
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
018 ME
EXTERNAL TYPE STORAGE FORMAT ENCRYPTED
Figure 24. File Documentation: Record Layout Screen
001 CUST_NO - This is the primary key to the physical file CUSTOMER.
008 - This is an MS type entry that marks the start of the definition of alternate key 1. SLSCUST is the alternate key definition name.
009 - This is the only M type entry in this alternate key definition. It specifies that the entire salesman id is the alternate key 1
010 - This is a ME type entry that marks the end of the definition of alternate key 1.
011 - This is an MS type entry that marks the start of the definition of alternate key 2. POSTCUST is the alternate key definition name.
012 - This is the first of two M type entries in this alternate key definition. It specifies that the first five characters of the zip code make up the first portion of alternate key 2.
013 - This is the second M type entry. It specifies that the first ten characters of the customer name makes up the final portion of alternate key 2.
014 - This is a ME type entry that marks the end of the definition of alternate key 2.
015 - This is an MS type entry that marks the start of the definition of alternate key 3. This key will always be unique because it contains the primary key field CUST_NO. POSTCUSU is the alternate key definition name.
016 - This is the first of two M type entries in this alternate key definition. It specifies that the entire zip code make up the first portion of alternate key 3.
017 - This is the second of the two M type entries. It specifies that the complete customer number makes up the second portion of alternate key 3.
018 - This is ME type entry that marks the end of the definition of alternate key 3.
The following three functions illustrate how to access the customer file by each of the alternate keys.
Topic ID: 720166