Create Physical File
DDS on IBM Power i systems defines physical files.
Physical Files
A physical file is a database file that contains data records. The data records are grouped into physical file members and each member has its own access path to the data. Normally, database files have only one member which, by default, is added to the file when the file is created. If the desired physical file has a record format with only one character field in arrival sequence or if the file is a source file, a DDS source file is not needed. To override attributes of the file after it has been created, use the Override Database File (OVRDBF) command before the file is opened. To change attributes of the file after it has been created, use the Change Physical File (CHGPF) command.
Simple DDS
The example below is simple. The DDS defines a phyiscal file with twelve fields. Only one record format name is allowed for a physical file, in the example, the record format name is RCAWCNF. The are no file level keywords. The only attributes assigned, other than the data type, are the TEXT keyword to describe the field, and the COLHDG keyword to define the default column heading associated with the field.
A****************************************************************
A* PHYSICAL FILE- CAWCNFPF *
A* *
A* FUNCTION - This file maps the fee waiver confirmation *
A* *
A* PROGRAMMER - Steve Croy 99/99/9999 iSoftwerks, inc *
A****************************************************************
A****************************************************************
A* FILE ATTRIBUTE SECTION *
A* *
A* MAXMBRS : 1 *
A* *
A****************************************************************
A****************************************************************
A* MODIFICATION LOG *
A* *
A* DATE PROGRAMMER DESCRIPTION *
A* *
A****************************************************************
A R RCAWCNF TEXT('WAIVER CONFIRMATION')
A CFOWN 6S 0 COLHDG('Own' 'Cde')
A TEXT('Account owner')
A CFPRJ 3S 0 COLHDG('Prj' 'Cde')
A TEXT('PROJECT')
A CFACT 8A COLHDG('Account')
A TEXT('Account')
A CFCNT 1S 0 COLHDG('Trans' 'Cent')
A TEXT('Transaction century')
A CFREF 4S 0 COLHDG('Ref' 'Code')
A TEXT('Reference Code')
A CFTRN 2A COLHDG('Trn' 'Code')
A TEXT('Transaction Code')
A CFAMT 7S 2 COLHDG('Amount')
A TEXT('Transaction Amount')
A CFDSC 10A COLHDG('Description')
A TEXT('Transaction description')
A CFDUE 8P 0 COLHDG('Due' 'Dte')
A TEXT('Due Date')
A CFPCT 4P 3 COLHDG('Bill' 'Pct')
A TEXT('Bill percent')
A CFRSN 3S 0 COLHDG('Rsn' 'Cde')
A TEXT('Reason Code')
A CFDFI 1A COLHDG('D/I')
A TEXT('Deferred/Immediate')
Keyed Physical File
DDS can describe a physical file as a keyed physical file. In DDL the equivalent would be a CREATE TABLE statement, followed by a CREATE INDEX statement. The keyword UNIQUE at the file level means that the key values will be unique to the data record. The record format (RSCOBJS) only has a TEXT attribute attached. The name of the record format can be the same as the file name specified in the Create Physical File (CRTPF) command. However, a warning message appears if the names are not unique. RPG does not allow record format and file names to be the same, so it is best not to use the file name as the record format name. Fields are defined at the record level, followed by key level entries--the fields named as the keys used to order the records.
A****************************************************************
A* PHYSICAL FILE- SCOBJSPF *
A* *
A* FUNCTION - This is object list for the SOFTCODE system *
A* *
A* PROGRAMMER - Steve Croy 99/99/9999 iSoftwerks, inc *
A****************************************************************
A****************************************************************
A* FILE ATTRIBUTE SECTION *
A* *
A* KEY FIELDS: EXOBNM, EXOBTP *
A* MAXMBRS : 1 *
A* *
A****************************************************************
A****************************************************************
A* MODIFICATION LOG *
A* *
A* DATE PROGRAMMER DESCRIPTION *
A* *
A****************************************************************
A UNIQUE
A R RSCOBJS TEXT('OBJECT DATA')
A EXCATS 3S 0 COLHDG('Cat' 'Cde')
A TEXT('CATEGORY')
A EXCSEQ 7S 0 COLHDG('Exec' 'Seq')
A TEXT('Execution Sequence')
A EXOBNM 10 COLHDG('Object' 'Name')
A TEXT('OBJECT NAME')
A EXOBTP 10 COLHDG('Object' 'Type')
A TEXT('OBJECT TYPE')
A EXDESC 50A COLHDG('Description')
A TEXT('DESCRIPTION')
A EXOBSR 10 COLHDG('Object' 'Source')
A TEXT('OBJECT SOURCE')
A EXOMBR 10 COLHDG('Source' 'Member')
A TEXT('SOURCE MEMBER')
A EXOBSL 10 COLHDG('Source' 'Library')
A TEXT('SOURCE SOURCE')
A EXCOMP 1 COLHDG('Cmp''Y/N')
A TEXT('COMPILE Y/N')
A EXMOVO 1 COLHDG('Mov''Y/N')
A TEXT('MOVE OBJECT Y/N')
A EXMOVS 1 COLHDG('MVS''Y/N')
A TEXT('MOVE SOURCE Y/N')
A EXACMD 1 COLHDG('Alt''Cmd')
A TEXT('ALTERNATE COMMAND')
A EXOBLB 10 COLHDG('Object' 'Library')
A TEXT('OBJECT LIBRARY')
*---
* AUDIT FIELDS
*---
A EXADDT 8S 0 COLHDG('Added' 'Date')
A TEXT('ADDED DATE')
A EXADTM 6S 0 COLHDG('Added' 'Time')
A TEXT('ADDED TIME')
A EXADUS 10A COLHDG('Added' 'User')
A TEXT('Added User')
A EXCHDT 8S 0 COLHDG('Change' 'Date')
A TEXT('Change Date')
A EXCHTM 6S 0 COLHDG('Change' 'Time')
A TEXT('Change Time')
A EXCHUS 10A COLHDG('Change' 'User')
A TEXT('Change User')
*---
A EXPROC 1 COLHDG('Prc''Y/N')
A TEXT('PROCESSED Y/N')
A EXPRDT 8S 0 COLHDG('Processed' 'Date')
A TEXT('Processed Date')
A EXPRTM 6S 0 COLHDG('Processed' 'Time')
A TEXT('Processed Time')
A EXPRUS 10A COLHDG('Processed' 'by User')
A TEXT('Processed by User')
*
A K EXOBNM
A K EXOBTP
Field Limits
The maximum number of fields in a record format is 8000. If any of the fields in the record format are date, time, timestamp, variable length, or allows the null value, then the actual maximum number of fields can be less than 8000. The maximum number of fields can vary depending on the number of fields and combinations of fields that occur within the record format. The maximum number of bytes in a record format is 32 766 if variable length fields are not included and 32 740 if variable length fields are included.|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8 00010A* PHYSICAL FILE CODING EXAMPLE from IBM 00020A REF(INVENCTL/INVENTORY) 00030A UNIQUE 00040A R ORDFMT TEXT(’Format for Purchase Orders’) 00050A ORDNBR 7 0 COLHDG(’Order’ ’Number’) 00060A ITMNBR R 10 00070A SUPNBR R +2 REFFLD(SUPID SUPLIB/SUPMST) 00080A QTYORD 5B 00090A K ORDNBR 00100A K ITMNBR ABSVAL
In this example, the file level REF keyword specifies a special type of file, called a
field reference file. This type file is generally used as a field library. Note that the
field SUPNBR is not defined in this DDS. The field definition is derived from the field
SUPID in a file named SUPMST in the library SUPLIB.
Data Types
| Entry | Meaning |
|---|---|
| P | Packed decimal |
| S | Zoned decimal |
| P | Packed decimal |
| S | Zoned decimal |
| P | Packed decimal |
| S | Zoned decimal |
| B | Binary |
| F | Floating point |
| A | Character |
| H | Hexidecimal |
| L | Date |
| T | Time |
| Z | Timestamp |
| 5 | Binary character |