IBM AS/400 manual Using Output Specifications, Files, editing DDS Referin the

				Defining Externally Described			Files
field	in	positions	49	through 62	and	assign	a match-level value
tions	65	and 66.
In this		example, the CUSTNO field in both records MSTREC and
WKREC	is	assigned	the	match-level	value	M1.

.2/ To assign a field indicator to a field in an externally des specify the record-format name in positions 7 through 16 of identification line. On the field-description line, specify th positions 49 through 62, and specify an indicator in positions 74.

In this		example,		the field BALDUE in the record	WKREC is	te
zero	when		it is	read into the program. If the	field’s	val
cator	98	is	set	on.

Using Output Specifications

Output specifications are optional for an externally described file. operation codes such as WRITE and UPDATE that use the external rec description to describe the output record without requiring output the externally described file.

You can use output specification to control when the data is to be specify selective fields that are to be written. The valid entries

description		line	for an	externally described			file	are	output indicat
29),	field name (positions 30 -				43), and	blank	after (position 45). Ed
edit	codes	for	fields	written	to an externally described file are
for	the file. Device-dependent				functions	such	as	fetch	overflow (pos

space/skip (positions 40 - 51) are not valid in an RPG program for ex described files. The overflow indicator is not valid for externally

either. For a description of		how	to	specify	editingDDS Referin the-		DDS,	se
ence.
If	output specifications are	used	for an externally			described		file
name	is specified in positions	7 -	16	instead	of the	file name.

If all the fields in an externally described file are to be plac enter *ALL in positions 30 through 43 of the field-description line. I fied, you cannot specify other field description lines for that re

If you want to place only certain fields in the output record, ent positions 30 through 43. The field names you specify in these posit field names defined in the external record description, unless the on the input specifications. See Figure 135 on page 270.

You	should know about these considerations for using the output spec
an	externally described file:

¹In the output of an update record, only those fields specified specifications and meeting the conditions specified by the output placed in the output record to be rewritten. Fields not specifie

specifications are rewritten using the values that were read. Th offers a good method of control as opposed to the UPDATE operat that updates all fields.

Chapter 14. Defining Files269