The Demo Validate Key tool is designed to assist in cases where keys
are to be added to a file, but potential miskeying errors may allow
the addition of an existing record (or the existing record was
miskeyed). The Validate Key program returns an array of potential
alternate keys that can be checked against a data base.
Assume the operator is told to add an employee record and a Social
Security Number is provided as the key. If the key is provided
incorrectly or the operator incorrectly keys the value, the data base
can become contaminated with invalid or duplicate records.
The Demo Validate Key command provides a demonstration function that
generates potential miskeying values. By default, a key of '123456'
and a length of 6 is passed to the program that generates alternate
keys. The DMOVALKEY command prints the alternate keys.
To try the various options provided, prompt for:
DMOVALKEY
and vary the options.
Use DSPSPLF to see the generated list of potential miskeying values.
The key value entered (KZVALU) will not appear in the list of
alternate keys.
Creating a program for your own data base
-----------------------------------------
A typical use of the function is to create a program that may be used
periodically to check for potential duplicates.
Sample code is provided in the TAAKEYAR2 RPG source member to:
- Read a data base file
- Use the key as input to generate potential miskey values
- Chain to the file using the potential miskey values
- Output a spooled file with the potential conflicts
You should be able to copy the code and make the required
modifications in a few minutes and try the result on one your data
files.
Use the following steps to begin your own specific version:
** Copy the source from the TAA Tool Archive to your source
member:
CPYTAA TAAARCMBR(TAAKEYAR2)
TOMBR(xxx)
TOSRCFILE(yyy/zzz)
** Edit the source and read the instructions included in the
source to modify the code for your specific use.
Both 'Required' and 'Optional' type temporary comments exist
for your review. For example, you are required to change to
your file and field names. You may add optional function such
as comparing on a field for 'State' to reduce the amount of
spooled output that must be reviewed.
** When the temporary comments are no longer needed, remove them
with the command:
RMVSRCCMT MBR(xxx) SRCFILE(yyy/zzz)
The same basic approach may also be used for any other use of the
program that generates the potential miskey values.
Options with the TAAKEYAR program
---------------------------------
The TAAKEYAR program generates the list of potential miskeying
values. The program is passed 4 parameters:
** An externally described data structure including the key to
generate potential miskeying values from, the setting of
various options, and the return number of array elements
generated.
** The first segment of the returned array of values. The
potential size of the array is large so the array is passed
back as 3 segments. Standard code in the sample program
places each segment into the proper place in the array.
** The second segment.
** The third segment.
The following fields must contain a value in the Externally Described
data structure to be passed.
KZVALU The key to be passed which will be used to generate
potential miskeying values.
KZLEN The maximum length of the key. It must be a value
between 1 and 15. Note that in the DMOVALKEY
function, the key is limited to 14 bytes.
Regardless of the options selected, the program will always return
generated miskeying values where a two character transposition may
have occurred. For example, if the key is 123456, the operator may
have entered it as 213456, 132456, ... 123465.
The following are options that may be specified and determine what
keys will be generated.
KZFIXL A *YES/*NO value for whether your key is fixed
length. For example, a ZIP code must be 5 digits in
length. *NO is the default. A blank value is
assumed to be *NO. If *NO is used, values with a
dropped character will be generated. For example, a
key of 123456 will generate potential miskeying
values of 23456, 13456, ... 12345.
KZNUM A *YES/*NO value for whether your key has only
digits. For example, a ZIP code must be numeric
only. *NO is the default. A blank value is assumed
to be *NO.
Specifying a *YES value prevents other parameters
such as KZCHGU and KZCHGL from being *YES.
KZCHGD A *YES/*NO value for whether the program should
generate potential values where one of the
characters will vary with a digit of 0-9. *NO is
the default and will not generate any alternate keys
where the key value characters are changed to
digits. A blank value is assumed to be *NO.
If *YES is specified, alternate keys will be
generated with 0-9 replacing any character (the same
character is not generated). For example, if the
key is 123456, the first digit could be mis-keyed as
0, 2 - 9. The second digit could be also be
miskeyed as 0, 1, or 3 - 9, etc.
KZCHGU A *YES/*NO value for whether the program should
generate potential values where one of the
characters will vary with a upper case of A-Z. *NO
is the default and will not generate any alternate
keys where the key value characters are changed to
upper case. A blank value is assumed to be *NO. If
KZNUM(*YES) is specified, *NO must be used.
If *YES is specified, alternate keys will be
generated with upper case letters replacing any
existing values (the same upper case character is
not generated). For example, if the key is 123456,
the first digit could be mis-keyed as A - Z. The
second digit could also be miskeyed as A - Z, etc.
A *YES, will generate several potential miskeying
values.
KZCHGL A *YES/*NO value for whether the program should
generate potential values where one of the
characters will vary with a lower case of a-z. *NO
is the default and will not generate any alternate
keys where the key value characters are changed to
lower case. A blank value is assumed to be *NO. If
KZNUM(*YES) is specified, *NO must be used.
If *YES is specified, alternate keys will be
generated with lower case letters replacing any
existing values (the same lower case character is
not generated). For example, if the key is 123456,
the first digit could be mis-keyed as a - z. The
second digit could also be miskeyed as a - z, etc.
A *YES, will generate several potential miskeying
values.
KZDBL A *YES/*NO value for whether the program should
generate potential values where each character is
doubled. *NO is the default meaning none of the
characters are doubled. A blank value is assumed to
be *NO. If KZFIXL(*YES) is specified, *NO must be
used.
*YES may be specified to cause a doubling. For
example, if the key is 123456, the key could be
entered as 1123456, 1223456 ... 1234566. A *YES,
will generate several potential miskeying values.
DMOVALKEY parameters *CMD
--------------------
KZVALU The value which will be used to generate alternate
keys. The value cannot be blank.
KZLEN The maximum length of the KZVALU field. It must be
in a range of 1 - 14. Note that the TAAKEYAR
program supports up to 15 characters.
KZFIXL A *YES/*NO parameter for whether the field is fixed
length. *NO is the default meaning the KZVALU value
may be altered in length for the generated keys.
This includes dropping a character and allows
KZDBL(*YES).
KZNUM A *YES/*NO parameter for whether the field is
numeric only. *NO is the default meaning the value
may contain any character.
*YES may be entered if the key will only contain
digits. Entering *YES prevents a *YES value for
KZCHGU and KZCHGL.
KZCHGD A *YES/*NO parameter for whether to generate digit
alternatives for each of the characters entered.
*NO is the default meaning substitute digits will
not be used to generate the alternate values.
*YES may be entered if the alternate keys should
include substitute digit values. For example,
123456 becomes 023456, 223456, ... 923456, 103456,
etc.
KZCHGU A *YES/*NO parameter for whether to generate upper
case alternatives for each of the characters
entered. *NO is the default meaning substitute
upper case characters will not be used to generate
the alternate values. *YES may be entered if the
alternate keys should include substitute upper case
values. For example, 123456 becomes A23456, B23456,
... Z23456, 1A3456, etc.
KZCHGL A *YES/*NO parameter for whether to generate lower
case alternatives for each of the characters
entered. *NO is the default meaning substitute
lower case characters will not be used to generate
the alternate values.
*YES may be entered if the alternate keys should
include substitute lower case values. For example,
123456 becomes a23456, b23456, ... z23456, 1a3456,
etc.
KZDBL A *YES/*NO parameter for whether to generate double
characters. *NO is the default meaning no double
characters are generated.
*YES may be entered if the alternate keys should
include doubling of the characters. For example,
123456 becomes 1123456, 1223456, ... 1234566.
Restrictions
------------
None.
Prerequisites
-------------
The following TAA Tools must be on your system:
EDTVAR Edit variable
FILEFDBCK File feedback
RTVVALA Retrieve variable value attributes
RTVSYSVAL3 Retrieve system value 3
SNDCOMPMSG Send completion message
SNDESCMSG Send escape message
SNDSTSMSG Send status message
Implementation
--------------
None, the tool is ready to use.
Objects used by the tool
------------------------
Object Type Attribute Src member Src file
------ ---- --------- ---------- ----------
DMOVALKEY *CMD TAAKEYA3 QATTRPG
TAAKEYAC3 *PGM CLP TAAKEYAC3 QATTCL
TAAKEYAR *PGM RPG TAAKEYAR QATTRPG
TAAKEYAR2 QATTRPG
TAAKEYAR3 *PGM RPG TAAKEYAR3 QATTRPG
TAAKEYAP *FILE PF TAAKEYAP QATTRPG
TAAKEYAP is the Externally Described Data Structure.
Structure
---------
DMOVALKEY Cmd
TAAKEYAC3 CL
TAAKEYAR3 RPG
TAAKEYAR is the program that generates the alternate keys.
TAAKEYAR2 is the sample code to be copied for using the TAAKEYAR
program.
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