HP 3000 Manuals HP 3000 Manuals
The Input Specification Fields (Cont.)
Field Name (Columns 53-58) (Cont.)
Matching/Chaining Fields (Columns 61-62).
This field contains either a matching or a chaining code for the field.
If you're not using matching or chaining fields, leave this field blank.
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| | |
| Columns 61-62 | Description |
| | |
--------------------------------------------------------------------------------------------
| | |
| C1-C9 | This is a chaining field identified by this code. |
| | |
| M1-M9 | This is a matching field identified by this code. |
| | |
| blank | The field is neither a matching nor a chaining field. |
| | |
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C1-C9 (Chaining fields)
Chaining field codes let you identify the fields to be used in retrieving
records from a direct-access chained MPE file. (A chained file can also
be a TurboIMAGE or KSAM file.) A chaining field code marks a field as a
chaining field. A chaining field contains addresses of records that you
want to access in a chained file. Chaining takes place before
detail-time processing.
There are two ways to access a chained file:
* You can use the CHAIN Calculation Specification operation. This
method may be more flexible than the next method because you can
use indicators to condition the operation.
* You can assign one or more chaining field codes as described in
this section (this is called "input chaining"). This method reads
the chained file automatically each time a record is selected for
processing that has a chaining field. You must enter a File
Extension Specification to associate the chaining file to the
chained file.
Figure 7-15 shows how chaining takes place. A program reads a record
from a transaction (chaining) file on disk that contains a customer
number and the customer charge amount. This file does not contain the
mailing address of the customer. The program obtains this address by
using the chaining field (customer name) to access the customer's record
in the chained file. At detail time in the HP RPG logic cycle, the
mailing address is retrieved and the program can print the customer
bill with mailing label. Figure 7-16 shows how to enter the
specifications for this example using chaining field codes.
![[]](../../pic3k/M013219/FFN403c50.gif)
Figure 7-15. Chaining to a Direct-Access File
You can have up to nine chaining fields per record type. (This lets you
access more than one chained file for each record.) The chaining field
codes do not have a rank based on their number. You determine the order
of the chaining fields by the sequence in which you enter the Input
Specifications. For example, if you assign C3 to the first field in a
record and C2 to the next field and C5 to the third, the chained files
are read in this order: C3, C2, C5.
Chaining fields can contain:
* Numeric relative record addresses of records to be accessed in the
chained file.
* Alphanumeric or numeric keys for records to be accessed in the
chained file. (The chained file must be a KSAM or TurboIMAGE file
processed by key.)
You can assign the same chaining field code to more than one field,
creating a split chaining field. Split chaining fields are combined to
form one chaining field. They can be adjoining or non-adjoining fields.
The first chaining field for the specification defines the leftmost
position of the combined chaining field. The last field defines the
rightmost position of the combined chaining field.
When assigning chaining field codes, follow these rules:
1. Do not use look-ahead fields or arrays as chaining fields.
2. Do not enter L or R (for leading or trailing arithmetic signs) in
the Data Format Field (column 43). If you do, chaining field
codes specified for the record type are ignored.
3. Do not intermix lines containing split chaining fields with those
containing regular chaining fields.
4. If the chaining field contains relative disk addresses, the field
must be defined as numeric.
5. If you want to use the same chaining field to read more than one
chained file, define a separate chaining field for each file but
use the same starting and ending positions for each of them. Also
use different names and chaining codes.
Example
Figure 7-16 shows the specifications that perform the chaining
illustrated in Figure 7-15 . The customer names and charge amounts
are stored in the chaining file TRANSAC. The customer mailing addresses
and other information are contained in the KSAM file MASTER. The first
field in TRANSAC, CUST, contains the customer name and it is identified
as the chaining field by the code C3. When MASTER is read, the record
whose CUST field matches the name in CUST (TRANSAC) is selected.
___________________________________________________________________________________
| |
| 1 2 3 4 5 6 7 |
| 678901234567890123456789012345678901234567890123456789012345678901234|
| _______________________________________________________ |
| |
| 1 FTRANSAC IP F 80 CARD |
| 2 FMASTER IC F 256RI5AI 1 DISK |
| |
| 3 EAAC3TRANSAC MASTER |
| |
| ITRANSAC AA 01 80 CT |
| 4 I 01 15 CUST C3 |
| I 16 200RECNO |
| I 21 25 AMOUNT |
| IMASTER BB 02 80 CM |
| I 01 15 CUST |
| I 16 25 STREET |
| I 25 35 CITY |
| I 35 40 STATE |
| I 41 45 ZIP |
| |
| |
___________________________________________________________________________________
Figure 7-16. Specifying Chaining Fields Using the Input Specification
M1-M9 (Matching fields)
You can use matching fields with sequential primary and secondary files
having any file organization (when you do, these files are called
matching files). Matching field codes perform two functions in a
program, depending on the number of files to which you assign them.
These functions are summarized below and are explained in detail in the
paragraphs which follow:
* When used with one file, they identify the fields to be
sequence-checked if the Input Sequence Field (column 18) of the
File Description Specification requests sequence-checking.
* When used with two or more files, they identify the fields to be
matched on input.
If you use matching field codes for only one file in a program, they
identify the fields to be sequence-checked. (You can sequence-check
input, combined and update files only.) You can use one or all of the
matching field codes. If you use more than one, the fields are treated
as a single control field. The fields associated with the higher
matching field codes come first, followed by the lower-ranking ones. For
example, the field associated with M9 comes first followed by the field
associated with M8 and so on. Be sure that the Input Sequence Field
(column 18) of the File Description Specification specifies the sequence
you want to use. If a sequence error occurs, an error message is printed
and the error response specified by the Error Response Field (columns
56-71) of the Header Specification, if any, is performed.
Example
Figure 7-17 shows how to assign matching field codes to three fields
(DEPT, DIV and BRANCH) in the file INFILE. M3 is assigned to the major
control field, BRANCH.
If INFILE contained the following three records and if ascending sequence
is specified for the file in column 18 of the File Description
Specification, the DIV code in the third record will cause a sequence
error.
DEPT: DIV: BRANCH:
003 005 01
002 006 01
001 004 01
___________________________________________________________________________________
| |
| 1 2 3 4 5 6 7 |
| 678901234567890123456789012345678901234567890123456789012345678901234|
| _______________________________________________________ |
| |
| IINFILE |
| I 1 10 IDNO |
| I 21 30 DEPT M1 |
| I 31 40 DIV M2 |
| I 41 45 BRANCH M3 |
| |
| |
___________________________________________________________________________________
Figure 7-17. Using Matching Field Codes to Sequence-Check a File
When you assign matching field codes to fields in more than one file, the
fields are used as control fields for matching-record processing.
Normally (when you do not specify matching-record processing), records
are not matched; all records in the primary file are processed first,
then records from each secondary file are processed in the order in which
you enter them in the File Description Specifications (this is called the
"primary/secondary processing order"). When using matching-record
processing (when you enter matching code fields for two or more files),
records are selected for processing in the order of the matching fields
(this is called the "matching-record processing order"). When the
matching fields are equal, the matching-record indicator (MR) is turned
ON and operations conditioned by the MR indicator are performed. All
matching records in the primary file are processed first followed by
matching records in the secondary file, in the order in which the File
Specifications are entered. Figure 7-18 illustrates how
matching-record processing works and the narrative below describes it in
detail.
1. The first record in each input, update or combined primary and
secondary file is read. A record is selected and processed
through the logic cycle.
2. At the start of the next cycle, the next record from the file just
processed is read.
3. If one of the files is forced (see the FORCE Calculation
Specification operation), its record is selected.
4. If a file does not use matching fields and it is a primary file,
its record is selected. If not, the record from the first
secondary file is selected.
5. If all of the files use matching fields, the fields are compared.
If you specified an alternating collating sequence, fields are
compared using that sequence. If a sequence error occurs, the
response that you entered in the Error Response Field (column
56-71) of the Header Specification, if any, is performed.
If the fields do not match and the records are in ascending order,
the record with the lowest matching field is selected. If the
records are in descending order, the record with the highest
matching field is selected.
If the fields are equal, the record from the primary file is
selected, followed by any other records from the primary file
having the same matching field value. Secondary records are
processed next in the order in which their File Description
Specifications are entered.
The matching-record (MR) indicator is turned ON before detail-time
Calculation Specification processing. It remains ON (unless you
turn it OFF with a Calculation Specification operation) until this
point in the next cycle.
![[]](../../pic3k/M013219/FFN433c50.gif)
Figure 7-18. Matching-Record Processing
When you use matching field codes, follow these rules:
1. For each matching file, enter the same sequence in the Input
Sequence Field (column 18) of the File Description Specification.
2. Assign matching field codes to at least one record type in two or
more files. If you do not, matching-record processing does not
take place. When you use more than one matching field code, all
fields in the control group must match before the MR indicator is
turned ON. If you assign M5, M4, M3 and M2, all four fields from
the primary file must match all four fields from the secondary
file. You do not have to assign matching field codes to each
record type in a file.
When any matching field (that has the same matching field code) is
numeric, all of them are treated as numeric. For example, if one
matching field contains 03 and another contains _3, they are
considered equal. Also, arithmetic signs and decimal points are
ignored in matching fields. For example, a field containing 7 is
considered equal to a field containing -0.07.
3. Use the same matching field codes for each matching file. The
field names to which you assign them, however, do not have to be
the same (field names are not used in matching).
4. Be sure that all fields with the same code are the same length and
contain the same format (alphanumeric or numeric). Matching
fields in binary format are not allowed.
5. Make sure that the combined length of all matching fields does not
exceed 256.
6. When you use more than one code, assign them to fields in the
order you want these fields combined to form the control field.
The fields are combined in the order M9 to M1. For example, if M3
is assigned to field XXX, M7 is assigned to ZZZ and M1 is assigned
to YYY, the fields are combined as follows:
ZZZXXXYYY
7. Do not assign the same matching field code to more than one field
within a record type. Matching fields cannot be split in this
manner.
Example
Figure 7-19 shows how to assign matching field codes to fields in the
files ALPHA and BETA. M1 is assigned to field DATA1 in file ALPHA and to
field DATA4 in file BETA. M2 is assigned to field DATA2 in file ALPHA and
to field DATA3 in file BETA. When the contents of these matching fields
are equal, the MR indicator is turned ON.
___________________________________________________________________________________
| |
| 1 2 3 4 5 6 7 |
| 678901234567890123456789012345678901234567890123456789012345678901234|
| _______________________________________________________ |
| |
| IALPHA AA 01 80 CA |
| I 1 5 DATA1 M1 |
| I 6 10 DATA2 M2 |
| IBETA BB 021 80 CB |
| I 21 25 DATA3 M2 |
| I 31 35 DATA4 M1 |
| |
| |
___________________________________________________________________________________
Figure 7-19. Assigning Matching Field Codes
Field Record Relation (Columns 63-64).
When you use OR lines to define record types, and some of the fields are
not contained in all types, you can enter an indicator in this field to
associate those input fields with the appropriate record type.
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| | |
| Columns 63-64 | Description |
| | |
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| | |
| 01-99 | General indicator that relates this field to a specific record |
| | type. |
| | |
| F0-F9 | Function key indicator that relates this field to a specific |
| | record type. |
| | |
| H1-H9 | Halt indicator that relates the field to a specific record type. |
| | |
| KA-KN, | Command key indicator that regulates the acceptance of data from |
| KP-KY | the file. |
| | |
| L1-L9 | Control-level indicator that regulates acceptance and use of |
| | data from t if a control break occurs. Data is accepted only |
| | when the indicator is turned ON. |
| | |
| LR | Last-record indicator that relates the field to a specific |
| | record type. |
| | |
| MR | Matching-record indicator that regulates use and acceptance of |
| | data from matching field. Data is accepted only when the |
| | indicator is turned ON. |
| | |
| OA-OG, OV | Overflow indicator that relates the field to a specific record |
| | type. |
| | |
| U1-U8 | User indicator that conditions the use of the field. |
| | |
| 1P | First-page indicator, used as a general indicator, that relates |
| | the file to a specific record type. |
| | |
| blank | The field appears in all record types for this OR relationship. |
| | |
--------------------------------------------------------------------------------------------
When using OR lines, you define a field once even though it appears in
different record types. This eliminates duplicate coding for those
fields that are identical. To distinguish a field that is unique,
associate an indicator with it using this field. Use the same
indicator that you associated with the record type in the Record
Indicator/Look-Ahead/Trailer/Data Structure Field (columns 19-20). When
the indicator is ON, it conditionally identifies the field as belonging
to the associated record type. (See the RPG logic cycle section in the
HP RPG Programmer's Guide for details on how the indicators are used.)
For example, you can use the general indicator 10 in this field. This
associates the field with the record type having indicator 10 in columns
19-20.
When two control fields (or matching fields) have the same control-level
indicator (or matching field code), you can enter an indicator in one of
these fields or both of them. Only the field associated with the
indicator that is ON is used. The field that does not have an indicator
associated with it is used (if defined first) when the indicator is
turned OFF.
When you enter an indicator with control-level, matching or chaining
fields, follow these rules:
1. Enter specifications that do not use this field before those that
do.
2. Enter an indicator for matching and control-level fields that
matches the record-identifying indicators for the record type.
3. Group all fields together that relate to one record type. Within
the groups, you can enter the fields in any order.
4. Assign the same indicator to all fields that belong to a split
control field. Define them together as a group.
Example
Figure 7-20 defines the file INPUT that contains two different types
of records. The general indicator 01 specifies that the field ALPHA
belongs to record type A. GAMMA and DELTA also belong to record type A
because they do not have an indicator associated with them. The general
indicator 02 specifies that the field BETA belongs to record type B.
Since GAMMA and DELTA do not have an indicator associated with them, they
also belong to record type B.
___________________________________________________________________________________
| |
| 1 2 3 4 5 6 7 |
| 678901234567890123456789012345678901234567890123456789012345678901234|
| _______________________________________________________ |
| |
| IINPUT AA 01 1 CA |
| I OR 02 1 CB |
| 1 I 2 5 ALPHA 01 |
| 2 I 6 10 BETA 02 |
| I 11 15 GAMMA |
| I 16 20 DELTA |
| |
| |
___________________________________________________________________________________
Figure 7-20. Using Indicators to Associate Fields with Record Types
Field Indicators (Columns 65-70).
This field lets you test for positive values, negative values, zeros or
blanks in the field.
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| | | |
| Column | Value | Description |
| | | |
-----------------------------------------------------------------------------------------------
| | | |
| Plus (65-66): | 01-99, F0-F9, H1-H9, | The indicator used for |
| | KA-KN, KP-KY, | testing numeric fields for |
| | L1-L9, LR, MR, | positive data. |
| | OA-OG, OV, | |
| | U1-U8, 1P | |
| | | |
| | blank | Do not test data in this |
| | | field. |
| | | |
| Minus (67-68): | 01-99, F0-F9, H1-H9, | The indicator used for |
| | KA-KN, KP-KY, | testing numeric fields for |
| | L1-L9, LR, MR, | negative data. |
| | OA-OG, OV, | |
| | U1-U8, 1P | |
| | | |
| | blank | Do not test data in this |
| | | field. |
| | | |
| Zero or Blank (69-70): | 01-99, F0-F9, H1-H9, | The indicator used for |
| | KA-KN, KP-KY, | testing numeric fields for |
| | L1-L9, LR, MR, | zeros or blanks or |
| | OA-OG, OV, | alphanumeric fields for |
| | U1-U8, 1P | blanks. |
| | | |
| | blank | Do not test data in this |
| | | field. |
| | | |
-----------------------------------------------------------------------------------------------
When you enter an indicator in this field, it is turned ON when the
condition that you're testing for is true. It is OFF when the condition
is not true. For instance, you can use a halt indicator to check a field
for a negative quantity. When a negative quantity is encountered, the
indicator turns ON and causes a halt at the end of the current cycle
(unless you entered a pre-response in the Error Response Field (columns
56-71) of the Header Specification.
When using indicators in this field, remember that:
1. An indicator used for positive or negative testing is OFF when the
program begins. It is turned ON when a record is read containing
a positive or negative value in the field.
2. An indicator used for zero or blank testing is OFF when the
program begins, unless you turn it ON by using the Indicator
Setting Field (column 42) of the Header Specification. It is
turned ON when a record is read that contains zeros or blanks in
the field.
3. When you assign two or three field indicators to one input field,
only the indicator which tests for the true condition is turned
ON; the others are turned OFF.
4. When you assign the same indicator to fields in different record
types, its ON/OFF status reflects the current record being
processed. The indicator remains ON until the field no longer
meets the testing criteria of the indicator.
5. You can turn indicators ON and OFF with the SETON and SETOFF
Calculation Specification operations.
Example
Figure 7-21 shows how to use field indicators to test input data.
The field POSDAT is tested for positive values. NEGDAT is tested for
negative numbers and the field NODAT is tested for zeros or blanks. When
any of the conditions are true, calculations and output conditioned by
the indicators are performed.
___________________________________________________________________________________
| |
| 1 2 3 4 5 6 7 |
| 678901234567890123456789012345678901234567890123456789012345678901234|
| _______________________________________________________ |
| |
| IINPUT AA 01 1 CY |
| I OR 02 1 CZ |
| 1 I 1 102POSDAT 0110 |
| 2 I 11 152NEGDAT 02 11 |
| 3 I 16 202NODAT 12 |
| |
| |
___________________________________________________________________________________
Figure 7-21. Using Field Indicators to Test Input Data
Program Name (Columns 75-80)
This field contains the program name. The format for this field is
discussed in Chapter 2.