File Management - IBM

and timestamp fields are initialized to the current system date and time. If *NULL
is specified on the DFT keyword, only the default buffer value is used. A *NULL
default is ignored.
If the from-file or to-file is a device file or an inline data file, copy automatically
adds or deletes the source sequence number and date fields for each record copied.
If one file is a data file and the other a source file, you must specify
FMTOPT(*CVTSRC) to perform the copy. The sequence number and date fields are
added or deleted as appropriate and the data part of each record is copied without
regard to the other field definitions in the file record formats. The SRCSEQ
parameter can be used to control how the sequence numbers are created, provided
SRCOPT(*SEQNBR) is also specified.
For database-to-database copies, you can reconcile any differences in record
formats by specifying:
v *DROP to drop those fields in the from-file record format for which there are no
fields of the same name in the to-file record format.
v *MAP to convert fields in the from-file to the attributes of like-named fields in
the to-file and to fill extra fields in the to-file, that are not in the from-file, with
their default values. The default values are:
– The parameter value (including *NULL) for the DFT keyword, if specified for
the field
– Blanks (for character fields without the DFT keyword)
– Zeros (for numeric fields without the DFT keyword)
– Current date, time, or timestamp for those type fields without the DFT
keyword
*MAP is required if fields with the same name are in different positions in the file
record formats, even though these fields have the same attributes.
v *DROP and *MAP to drop fields in the from-file not named in the to-file and to
convert remaining fields through mapping rules to fit the to-file fields that have
different attributes or positions.
v *NOCHK to disregard the differences. Data is copied left to right directly from
one file to the other. Null values are ignored. The copied records are either
truncated or padded with default buffer values. Because no checking is done,
fields in the to-file may contain data that is not valid for the field as defined.
Dropping and mapping fields are based on a comparison of field names. Unless all
the fields in the from-file have the same name in the to-file, you must specify
*DROP. If the names are the same, but the attributes or position in the record is
different, you must specify *MAP. Dropped fields are not copied. There must be at
least one like-named field in both record formats to do mapping.
When *MAP is specified, fields in the to-file record format that do not exist in the
from-file record format are filled with their default values, as described earlier in
this section. For fields that have the same name and attributes, the field in the
from-file record format is mapped to the field with the same name in the to-file
record format, even if their positions in the formats are different.
For example, the field CUSNO is the first field in the record format ORDHD, but it
is the second field in record format ORDHD1. When the CUSNO field is copied
with *MAP, it is mapped to the second field of ORDHD1.
Chapter 4. Copying files 107