Physical Files:

Overview:

This module enables the student to understand the concept of Physical and Logical File.

Outline:

Topics covered,

· Physical file creation

· Logical file creation

Concept of Keyed and Sequential access
Commands related to files
Add records to physical file

Objective:

By the end of this module, the student should be able to:

Create a Physical file
Create a Logical file
Understand the concept of Physical files.
Understand the part of Logical files.
Commands related to files.
Add records to physical file using STRDFU,UPDDTA.

Create a Physical File with or without a key field

Introduction:

The AS/400 database, DB2/400 is part of the AS/400 operating system. The standard method of creating files is to define the specifications of the file using DDS(Data Description Specification). Of course DDS is used for other things on the AS/400 like defining display files and print files.

Defining a physical file using DDS

An externally described file is one in which the record and field descriptions are defined outside of a program. The two types supported on the AS/400 are physical and logical files. Physical files are explained in this chapter and logical files in next.

Similar to disk files on non-data based computer system, physical files contain the actual data records. The attributes of the records may be data based-defined or program-defined. If they are database-defined, the field definitions are specified outside of a program. For program-defined files, the field attributes must be included in the program in the traditional RPG II way.

Physical files may be organized as non-keyed or keyed sequence files. The type of organization determines the access path followed when the file is processed.

A non-keyed file is similar to the standard sequential organization file in which keys are not specified. Records, which are processed in the order that they were loaded, may be read, written, and updated using sequential or relative record processing methods. Direct file organization is not supported on the AS/400. The processing methods unique to that file type, however, may be simulated for arrival of key-sequenced files.

A keyed sequence file is similar to the traditional indexed sequential file organization in which one or more fields may be specified as a key. Processing features unique to key sequence file are the following:

Records may be accessed sequentially in key value order or randomly by the value of a key.
Records may be accessed in arrival sequence order (ignores key value order).
Composite keys may be defined by specifying more than one field within the body of a record. These fields need not be contiguous.
Any field in the body of the record may be specified as a key field after the file is created. However, a logical file must be used to process the physical file by the new key(s).
In addition to standard sequential and random processing, files may be read backward or accessed by a relative record number.
The next record that is lower or higher than the specified key value may be accessed.

The steps for building a physical file are the following:

Design a record format based on some applications criteria.
Write the code on a Data Description Specifications (DDS) form.
Enter the DDS statements via the Source Entry Utility (SEU) and save.
Compile, debug, and store the error-free physical file object format.

Creation of physical file:

Notice that the first record has an "R" in position 17. This means that this line is specifying the record name. The "TEXT" is optional but helps to document the file. Shown in lab session.

After the line naming the record, each line describes a field. The field length and its data type follow the field name. Once you have entered the DDS source code, you must compile it. You do this by keying option 14 next to your member name on the PDM screen. Field length should not be greater than 10 characters.

Data Access:

You now have a database physical file, see Figure 1. This file has built into it the fields and their attributes. Let's modify this file definition to add key fields. If a physical file has key fields, programs can randomly access the records or read them sequentially in the order of the key fields.

The records are written to the file in arrival sequence. If you read the data by specifying keyed access, the records will read as though company number and customer number have sorted them. Also, your programs can randomly retrieve records.

Figure 1 - DDS for Physical File Without Key

Columns . . . : 1 71 Edit PB01U01D/ MYDDS

SEU==> STUDENT

FMT PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0002.00 A R RSTUD

0003.00 A ROLL 3S 0 COLHDG('ROLL NUMBER')

0004.00 A SNAME 5A COLHDG('STUDENT NAME')

0005.00 A CCD 3S 0 COLHDG('COURSE CODE')

0006.00 A CORS 5A COLHDG('COURSE NAME')

0007.00 A ADD 5A COLHDG('ADDRESS')

****************** End of data ****************************************

F3=Exit F4=Prompt F5=Refresh F9=Retrieve F10=Cursor F11=Toggle

F16=Repeat find F17=Repeat change F24=More keys

Figure 2 - DDS for Physical File With Key Fields

Columns . . . : 1 71 Edit PB01U01D/MYDDS

SEU==> STUDENT

FMT PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0001.00 UNIQUE

0002.00 A R RSTUD

0003.00 A ROLL 3S 0 COLHDG('ROLL NUMBER')

0004.00 A SNAME 5A COLHDG('STUDENT NAME')

0005.00 A CCD 3S 0 COLHDG('COURSE CODE')

0006.00 A CORS 5A COLHDG('COURSE NAME')

0007.00 A ADD 5A COLHDG('ADDRESS')

0008.00 A K ROLL

****************** End of data ****************************************

F3=Exit F4=Prompt F5=Refresh F9=Retrieve F10=Cursor F11=Toggle

F16=Repeat find F17=Repeat change F24=More keys

Creating Physical File:

To create physical file, press F6 (source entry utility) write source file name, Library name, source member, source type as ‘PF’ and text description.

Start Source Entry Utility (STRSEU)

Type choices, press Enter.

Source file . . . . . . . . . . > MYDDS Name, *PRV

Library . . . . . . . . . . . > PB01U01D Name, *LIBL, *CURLIB, *PRV

Source member . . . . . . . . . STUDENT Name, *PRV, *SELECT

Source type . . . . . . . . . . PF Name, *SAME, BAS, BASP...

Text 'description' . . . . . . . 'STUDENT DETAILS'

Bottom

F3=Exit F4=Prompt F5=Refresh F12=Cancel F13=How to use this display

F24=More keys

HIT ENTER

Columns . . . : 1 71 Edit PB01U01D/MYDDS

SEU==> STUDENT

FMT PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

IPPF *************** Beginning of data *************************************

F3=Exit F4=Prompt F5=Refresh F9=Retrieve F10=Cursor F11=Toggle

F16=Repeat find F17=Repeat change F24=More keys

NOTE : ‘IPPF’ IS INPUT PROMP FOR PHYSICAL FILE, USED TO DO FIELD ENTRIES IN PHYSICAL FILE.

Press enter Which gives you following prompt

Columns . . . : 1 71 Edit PB07U01O/MYRPG

SEU==> STUD4

FMT PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

'''''''

****************** End of data ****************************************

Prompt type . . . PF Sequence number . . . '''''''

Name Data Decimal

Type Name Ref Length Type Positions Use

Functions

F3=Exit F4=Prompt F5=Refresh F11=Previous record

F12=Cancel F23=Select prompt F24=More keys

THIS TABLE DESCRIBES YOU THE DETAILS OF ‘IPPF’ PROMPT.

HEADING	DESCRIPTION
Name type	Blank : Leave the field blank to indicate a Field Name. R : Type R in column 17 to indicate a Record Format Name.
Name	Type a Record Format, Field, or Key Field Name in this position. The maximum length allowed is 10 characters, beginning in column 19.
Ref	Type R in this field to use the reference function to copy attributes of a previously defined named field to the field you are now defining.
Length		Type a value to indicate the number of bytes in a Character field or the number of digits in a Numeric field.
Data Type		These are Data types which we use frequently: S : Type S to indicate Zoned Decimal data.(For Numeric value) F : Type F to indicate Floating Point data. A : Type A to indicate Character data. L : Type L to indicate Date data. P : Type P to indicate Packed Decimal data.
Decimal Position		Type a value from 0 to 31 to indicate the number of decimal positions to the right of the decimal point within a Packed Decimal, a Zoned Decimal, a Floating Point, or a Binary field.
USE		Type B or leave the field blank to indicate a field used for both input and output.
Functions		Use Keywords like COM Provides a comparison value (for reference function only). RANGE Provides a range of valid values (for reference function only).

Write your Record format as we discussed the sequence of PF in introduction.

Columns . . . : 1 71 Edit PB01U01D/MYDDS

SEU==> STUDENT

FMT PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0001.00 A R RSTUD

****************** End of data ****************************************

Prompt type . . . PF Sequence number . . . 0002.00

Name Data Decimal

Type Name Ref Length Type Positions Use Functions

R RSTUD

F3=Exit F4=Prompt F5=Refresh F11=Previous record

F12=Cancel F23=Select prompt F24=More keys

Note: Record format name is not having attributes like DATA TYPE and DECIMAL POSITION.

Hit enter and again write “IPPF’ to insert Field:

Now in second step you have to define fields having attributes field length, data type and decimal positions if field is numeric. Insert the define fields using same way.

While entering fields the values, which we provide for LENGTH, and DECIMAL POSITION are numeric must be RIGTHT align. To make it RIGHT ALIGN use right ‘Enter Key’ from numeric pad.

Columns . . . : 1 71 Edit PB01U01D/MYDDS

SEU==> STUDENT

FMT PF .....A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0002.00 A R RSTUD

0003.00 A ROLL 3S 0

0004.00 A SNAME 5A

0005.00 A CCD 3S 0

0006.00 A CORS 5A

0007.00 A ADD 5A

0008.00 A K ROLL

****************** End of data ****************************************

Prompt type . . . PF Sequence number . . . 0003.00

Name Data Decimal

Type Name Ref Length Type Positions Use

ROLL 3 S 0

Functions

F3=Exit F4=Prompt F5=Refresh F11=Previous record

F12=Cancel F23=Select prompt F24=More keys

PRESS F3

Exit

Type choices, press Enter.

Change/create member . . . . . . . Y Y=Yes, N=No

Member . . . . . . . . . . . . . STUDENT Name, F4 for list

File . . . . . . . . . . . . . . MYDDS Name, F4 for list

Library . . . . . . . . . . . . PB01U01D Name

Text . . . . . . . . . . . . . . PHYSICAL FILE FOR STUDENT

Resequence member . . . . . . . . N Y=Yes, N=No

Start . . . . . . . . . . . . . 0001.00 0000.01-9999.99

Increment . . . . . . . . . . . 01.00 00.01-99.99

Print member . . . . . . . . . . . N Y=Yes, N=No

Return to editing . . . . . . . . . N Y=Yes, N=No

Go to member list . . . . . . . . . N Y=Yes, N=No

Hit Enter

Work with Members Using PDM S653278B

File . . . . . . MYDDS

Library . . . . PB01U01D Position to . . . . .

Type options, press Enter.

2=Edit 3=Copy 4=Delete 5=Display 6=Print 7=Rename

8=Display description 9=Save 13=Change text 14=Compile 15=Create module...

Opt Member Type Text

STUDENT PF PHYSICAL FILE

Bottom

Parameters or command

===>

F3=Exit F4=Prompt F5=Refresh F6=Create

F9=Retrieve F10=Command entry F23=More options F24=More keys

To compile PF use command CRTPF or opt 14 against PF that create object of PF (as shown below).

Work with Members Using PDM S653278B

File . . . . . . MYDDS

Library . . . . PB01U01D Position to . . . . .

Type options, press Enter.

2=Edit 3=Copy 4=Delete 5=Display 6=Print 7=Rename

8=Display description 9=Save 13=Change text 14=Compile 15=Create module...

Opt Member Type Text

14 STUDENT PF PHYSICAL FILE

Bottom

Parameters or command

===>

F3=Exit F4=Prompt F5=Refresh F6=Create

F9=Retrieve F10=Command entry F23=More options F24=More keys

After writing 14 over Opt and press F4 that is same as CRTPF on command line with F4.

Create Physical File (CRTPF)

Type choices, press Enter.

File . . . . . . . . . . . . . . > STUDENT Name

Library . . . . . . . . . . . > PB01U01D Name, *CURLIB

Source file . . . . . . . . . . > MYDDS Name

Library . . . . . . . . . . . > PB01U01O Name, *LIBL, *CURLIB

Source member . . . . . . . . . > STUDENT Name, *FILE

Record length, if no DDS . . . . Number

Generation severity level . . . 20 0-30

Flagging severity level . . . . 0 0-30

File type . . . . . . . . . . . *DATA *DATA, *SRC

Member, if desired . . . . . . . *FILE Name, *FILE, *NONE

Text 'description' . . . . . . . *SRCMBRTXT

More...

F3=Exit F4=Prompt F5=Refresh F12=Cancel F13=How to use this display

F24=More keys

PRESS ENTER WHICH CREATES PHYSICAL FILES OBJECT. NOW TO UPDATE PF, WRITE ‘UPDDTA <FILE NAME> ‘ command on command line.

Work with Members Using PDM S653278B

File . . . . . . MYDDS

Library . . . . PB01U01D Position to . . . . .

Type options, press Enter.

2=Edit 3=Copy 4=Delete 5=Display 6=Print 7=Rename

8=Display description 9=Save 13=Change text 14=Compile 15=Create module...

Opt Member Type Text

STUDENT PF PHYSICAL FILE

Bottom

Parameters or command

===> UPDDTA

F3=Exit F4=Prompt F5=Refresh F6=Create

F9=Retrieve F10=Command entry F23=More options F24=More keys

Press F4 to see Parameter for UPDDTA command.

Update Data with Temp Program (UPDDTA)

Type choices, press Enter.

Data base file . . . . . . . . . STUDENT Name

Library . . . . . . . . . . . PB01U01O Name, *LIBL, *CURLIB

Member . . . . . . . . . . . . . *FIRST Name, *FIRST

Bottom

F3=Exit F4=Prompt F5=Refresh F12=Cancel F13=How to use this display

F24=More keys

Hit Enter. Add records to these fields.

WORK WITH DATA IN A FILE Mode . . . . : ENTRY

Format . . . . : RSTUD File . . . . : STUD

ROLL:

SNAME:

CCD:

CORS:

ADD:

F3=Exit F5=Refresh F6=Select format

F9=Insert F10=Entry F11=Change

INSERT DATA AS PER REQUIREMENT. PRESS F3 TO EXIT FROM FILE.

End Data Entry

Number of records processed

No of records added

Added . . . . . : 3

Changed . . . . : 0

Deleted . . . . : 0

Type choice, press Enter.

End data entry . . . . . . . Y Y=Yes, N=No

F3=Exit F12=Cancel

Press enter. After insertion of data do not compile the file which delete your data. Use ‘RUNQRY *N <FILENAME>’ to run or to see the content of physical file.

Work with Members Using PDM S653278B

File . . . . . . MYDDS

Library . . . . PB07U01D Position to . . . . .

Type options, press Enter.

2=Edit 3=Copy 4=Delete 5=Display 6=Print 7=Rename

8=Display description 9=Save 13=Change text 14=Compile 15=Create module...

Opt Member Type Text

STUDENT PF STUDENT DETAILS

More...

Parameters or command

===> RUNQRY *N STUDENT

F3=Exit F4=Prompt F5=Refresh F6=Create

F9=Retrieve F10=Command entry F23=More options F24=More keys

Press enter

Display Report

Report width . . . . . : 60

Position to line . . . . . Shift to column . . . . . .

Line ....+....1....+....2....+....3....+....4....+....5....+....6

ROLL NUMBER STUDENT NAME COURSE CODE COURSE NAME ADDRESS

000001 101 RAHUL 100 VB PUNE

000002 102 TITU 101 AS MUM

****** ******** End of report ********

Bottom

F3=Exit F12=Cancel F19=Left F20=Right F21=Split

KEYWORDS:

A) File level keywords:

Following are the File Level Keywords:

UNIQUE

FIFO (First In First Out)

LIFO (Last In First Out)

FCFO (First Change First Out)

1) UNIQUE: The "UNIQUE" record at the beginning of the source is used if you want the AS/400 to insist on having no records with duplicate keys. This is optional. At the end of the source code, there are two lines with "K" in position 17. These lines define the key fields.

2) FIFO LIFO FCFO: These keywords are used with the duplicate entries to specify the order.

Columns . . .: 1 71 Edit PB01U01D/MYDDS

SEU==> STUDENT

FMT PF ...A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0000.01 UNIQUE

0001.00 A R RSTUD

0002.00 A ROLL 3S 0

0003.00 A SNAME 5A

0004.00 A CORS 5A

0005.00 A ADD 5A

0006.00 A CITY 5A

0007.00 A K ROLL

****************** End of data ****************************************

F3=Exit F4=Prompt F5=Refresh F9=Retrieve F10=Cursor F11=Toggle

F16=Repeat find F17=Repeat change F24=More keys

LIKE ‘UNIQUE’ KEYWORD USE FIFO, LIFO AND FCFO KEYWORDS.

Record Level Keywords:

FORMAT (Format) keyword for physical and logical files

Use this record-level keyword to specify that this record format is to share the field specifications for a

previously defined record format. The name of the record format you are defining must be the name of the previously defined record format.

The format of the keyword is:

FORMAT([library-name/]database-file-name)

The database-file-name parameter is required. It is the name of the physical or logical file from which the previously defined record format is taken.

Create new physical file ‘student1’ and define only record format name with FORMAT keyword having filename which is to be reffered.

Columns . . .: 1 71 Edit PB01U01D/MYDDS

SEU==> STUDENT1

FMT PF ...A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0001.00 A R RSTUD FORMAT(STUDENT)

****************** End of data **************************************

F3=Exit F4=Prompt F5=Refresh F9=Retrieve F10=Cursor F11=Toggle

F16=Repeat find F17=Repeat change F24=More keys

COMPILE THIS FILE AND USE RUNQUERY OPTION TO RUN THE FILE.

The name of this record format (RSTUD) must be the same as the name of the record format in STUDENT. Like FORMAT ‘TEXT’ is also a record level keyword use as follows:

Columns . . .: 1 71 Edit PB01U01S/MYDDS

SEU==> STUDENT

FMT PF ...A..........T.Name++++++RLen++TDpB......Functions++++++++++++++++++

*************** Beginning of data *************************************

0001.00 A R RSTUD TEXT(‘STUDENT DETAILS’)

0002.00 A ROLL 3S 0

0003.00 A SNAME 5A

0004.00 A CORS 5A

0005.00 A ADD 5A

0006.00 A CITY 5A

0007.00 A K ROLL

****************** End of data ***************************************

F3=Exit F4=Prompt F5=Refresh F9=Retrieve F10=Cursor F11=Toggle

F16=Repeat find F17=Repeat change F24=More keys

The name of this record format (RSTUD) must be the same as the name of the record format in STUDENT.

Field Level Keywords:

ALIAS (Alternative Name) keyword for physical and logical files

Use this field-level keyword to specify an alternative name for a field. When the program is compiled, the alternative name is brought into the program instead of the DDS field name.

The format of the keyword is:

ALIAS (alternative-name)

The alternative name must be different from all other alternative names and from all DDS field names in the record format. If a duplicate is found, an error message appears on the field name or alternative name. When you refer to a field that has the ALIAS keyword, the ALIAS keyword is copied in unless the ALIAS keyword is explicitly specified on the referencing field.

Example:

The following example shows how to specify the ALIAS keyword.

|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8

00010A FIELDA 25A ALIAS(STUDENT NAME)

In the example, the alternative name for FIELDA is STUDENT NAME.

COLHDG (Column Heading) keyword for physical and logical files:

Use this field-level keyword to specify column headings used as a label for this field by text management, the query utility, the data file utility (DFU), and the screen design aid (SDA).

The format of the keyword is:

COLHDG (’line-1’ [’line-2’ [’line-3’]])

A maximum of three lines of 20 characters each is allowed. Each line of the column heading must be

enclosed in apostrophes. Use double apostrophes (’ ’) to specify apostrophes within column headings.

Use one or more blanks to separate the first column heading line from the second and the second from

the third.

For example, COLHDG (’Order’ ’Date’) is equivalent to TEXT (’Order Date’).

Example:

The following example shows how to specify the COLHDG keyword for a physical file.

|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8

00150A ROLL 5 0 COLHDG(’ROLL’ ’NUMBER’)

00160A SNAME 20 COLHDG(’Student’s Name’)

TEXT : This is record level as well as field level keyword which describes your field.

Example:

The following example shows how to specify the COLHDG keyword for a physical file.

|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8

00150A ROLL 5 0 TEXT(’ROLL NUMBER’)

00160A SNAME 20 TEXT(‘Student’s Name’)

CHECK

Use this field-level keyword to specify validity checking in display files.

The rules for specifying this keyword in a physical or logical file are similar to those for a display file.

However, only the following codes are allowed in physical or logical files:

Code Meaning

AB Allow blank

ME Mandatory enter

MF Mandatory fill

M10 IBM* Modulus 10 self-check algorithm

M10F IBM® Modulus 10 self-check algorithm

M11 IBM Modulus 11 self-check algorithm

M11F IBM Modulus 11 self-check algorithm

VN Validate name

VNE Validate name extended

|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8

00150A ROLL 5 0 CHECK(AB)

00160A SNAME 20 CHECK(MF)

Above example shows that roll number may be blank and student name is mandatory.

You cannot specify the CHECK(AB), CHECK(VN), CHECK(VNE), CHECK(M10), CHECK(M11),

CHECK(M10F), or CHECK(M11F) keywords on a floating-point field (F in position 35). You cannot specify the CHECK keyword on a hexadecimal field (H in position 35). Do not specify the CHECK keyword on a date, time, or timestamp field (L, T, or Z in position 35).

DESCEND (Descend) keyword for physical

Use this key field-level keyword to specify that the values of this character, hexadecimal, or numeric key field are retrieved in descending sequence. The default is ascending sequence. See “SIGNED (Signed) keyword for physical and logical files” on page 69 for an example of data sorted using the DESCEND keyword.

This keyword has no parameters.

Example:

The following example shows how to specify the DESCEND keyword for a logical file.

|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8

00010A KITEM

00020A KBALDUE DESCEND

COMP (Comparison) keyword for physical and logical files

Use this field-level keyword to specify validity checking for the field you are defining when it is referred to later during display file creation. COMP is equivalent to CMP.

The format of the keyword is:

COMP (relational-operator value) At the select/omit-field level, the format of the keyword is:

COMP (relational-operator field-name)

Valid relational operators are:

Relational Operator

Meaning

EQ Equal to

NE Not equal to

LT Less than

NL Not less than

GT Greater than

NG Not greater than

LE Less than or equal to

GE Greater than or equal to

Specify the value parameter at either the field level or the select/omit field level. Specify the field name

parameter only at the select/omit field level.

The RANGE Keyword

The RANGE keyword validates that the data in a field value is equal or greater than the lower value and less than or equal to the higher value specified in the RANGE key word.

The format of the keyword is:

Range (low-value high –value)

When the related field is defined as character , the low and high values must both be enclosed in single quotes. The quotes are omitted for numeric fields. Figure details two examples of the RANGE keyword.

The VALUES Keyword

The VALUES keywords validates that a field value is equal to one of the values included in the specified list. It is similar to the COMP keyword in that a relational test is made. However the VALUES keyword only performs an equal test on a list of values, whereas the COMP keyword may include any of the relational tests, but only for one value.

The format of the keyword is

VALUES (value-1[value-2….[value-1001])

One hundred values may be specified, each separated by at least one blank. A VALUES keyword specified with character fields must have each value in the list enclosed in single quotes. Numeric values are specified without quotes Identical to any relational comparison function, the value list must be the same type as the related field. Figure shows two coding examples of the VALUES keyword.

PHYSICAL FILE MAINTENANCE COMMANDS

Command	Description	Usage
CHGPF	Change physical file	Supports changes in the attributes of a physical file without requiring its recreation with the CRTPF command. The data in the physical file is not lost when CHGPF is executed.
CLRPFM	Clear physical file member	Clears a physical file member of all data records with-out deleting the file’s structure.
CPYF	Copy file	Copies the data stored in a physical file to an output device or another physical file. Either all of the records or only selected records may be copied. A variety of selection criteria may be specified such as a key or a relative record number range. When output is to a printer, either character or hexadecimal format may be specified. For readability, however, hexadecimal format is necessary if packed numeric values are stored in one or more fields of the record format.
DLTF	Delete File	Deletes the physical file’s object and any data stored in the file. A file cannot be deleted if a logical file has been created over it or if the file is in use.
DSPPFM	Display Physical File Member	Displays the field values in the records stored in a physical file. Records are displayed in arrival sequence even if the file was created as keyed. A character or hexadecimal display of the record values may be specified. Other than printing the current display with the values may be specified. Other than printing the current display with the Print key, printer output is not supported.
	Remove Member	Removes the specified member from the physical file and deletes all of the data stores in the member.
DSPPFD	Display Physical file Description

Entering the command on the command line of an AS/400 display and pressing F4 may execute any of these CL commands. One or more prompt screens will display enabling the programmers to enter command specific data.

Questions:

Q1. What is an externally defined file? What two types are supported on the AS/400?

___________________________________________________________________________

Q2 . Explain how any field included in the file in an ascending or descending order may process a physical file. “Sorting” is not an acceptable answer.

___________________________________________________________________________

Q3. Name the steps followed for building a physical file.

___________________________________________________________________________

Q4. How many record formats may be included in a physical file?

___________________________________________________________________________

Q5. What is the function of the following physical file keywords?

___________________________________________________________________________

COLHDG EDTWRD REFLD

DESCEND LIFO TEXT

EDTCDE REF UNIQUE

Q6 What CL command is used to display he attributes of a physical file? Name the CL command needed to display the field attributes of a physical file.

________________________________________________________________________

___________________________________________________________________________

Q7 Explain the function of he following physical file maintenance commands:

CHGPF CLRPFM CPYF

DSPPFM RMVM DLTF

Q8 How many default members are assigned when a physical file is created without changing any parameters? How is a file created to support more than one member?

___________________________________________________________________________

Q9. By what methods may data be loaded to a physical file?

___________________________________________________________________________

AS/400 Forum

Tuesday, December 3, 2013

Day-3.

Physical Files:

Create a Physical File with or without a key field

Defining a physical file using DDS

NOTE : ‘IPPF’ IS INPUT PROMP FOR PHYSICAL FILE, USED TO DO FIELD ENTRIES IN PHYSICAL FILE.

Name type

Ref

Length

Data Type

Decimal Position

USE

Functions

PRESS F3

Hit Enter

INSERT DATA AS PER REQUIREMENT. PRESS F3 TO EXIT FROM FILE.

LIKE ‘UNIQUE’ KEYWORD USE FIFO, LIFO AND FCFO KEYWORDS.

Record Level Keywords:

Field Level Keywords:

ALIAS (Alternative Name) keyword for physical and logical files

TEXT : This is record level as well as field level keyword which describes your field.

CHECK

DESCEND (Descend) keyword for physical

PHYSICAL FILE MAINTENANCE COMMANDS

Questions:

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