IBM AS/400 manual Arguments, a Partial, Referring to, Using Externally Described Disk Files

Using Externally Described Disk Files

Valid Search

Arguments

You can specify a search argument

in

the

ILE RPG

operations

CHAIN,

DEL

READE,

READPE, SETGT, and SETLL that specify a file name

or

a

record

name.

For

an

operation to a file name, the maximum number

of

fields

that

you

in

a

search argument

is equal

to

the

total

number

of

key

fields

valid

key.

For example, if all record types

in

a

file

do

not

contain

all of

fields, you can use a key list

(KLIST)

to

specify

a

search

argument

posed

only of the number of fields common

to

all

record

types in

the

contains

three

record

types,

the

key

fields

are

defined

as

follows:

–

REC1

contains

key

field

A.

–

REC2

contains key fields A and B.

–

REC3

contains

key

fields

A,

B,

and

C.

The search argument can only be a single field with attributes identi because field A is the only key field common to all record types. Th ment cannot contain a floating point, variable length, or null-capable field

For an operation to a record name, the maximum number of fields that specify in a search argument is equal to the total number of key fi record type.

If

the search

argument

consists

of

one

field, you can specify a lit

or

a

KLIST

name

with one

KFLD.

If

the

search argument is composed of

one field (a composite key), you must

specify a KLIST with multiple KFL

process null-valued keys a

KLIST

must

be used.

The attributes of each field in the

search argument must be identic

butes of the corresponding field in the

file or record key. The att

length,

the

data

type

and the number

of

decimal

positions.

The

attrib

in the key-field-information data table

of

the

compiler

listing. See

the

“Key

Field

Information”

on

page 434.

In all these file operations

(CHAIN,

DELETE, READE,

READPE,

SETGT,

and

SETLL), you can also specify a search

argument that

contains

fewer

than

number of fields valid for the file

or

record.

Such

a search

argume

partial

key.

Referring to		a Partial	Key
The	rules	for the	specification of a search argument that refers to
as	follows:

¹The search argument is composed of fields that correspond to the

(high-order) fields of the key for the file or record.

¹Only the rightmost fields can be omitted from the key list (KLIST)

argument

that

refers

to

a

partial

key.

For

example,

if

the total

k

record

is

composed

of

key

fields

A,

B,

and C, the

valid search

a

refer

to

a

partial

key

are field

A,

and

fields A

and

B.

¹Each field in the search argument must be identical in attributes sponding key field in the file or record. The attributes include t type, the number of decimal positions, and format (for example, pac zoned).

286 ILE RPG for AS/400 Programmer's Guide