Be aware of the considerations when describing a database file
that contains DBCS fields.
- If you describe DBCS fields in the DDS, the system treats the file as
a DBCS file. You do not need to specify IGCDTA(*YES) on the file creation
command to identify the file as DBCS.
- The data type of a field in a physical file can be changed as follows
when you refer to that field in a logical file:
| Physical file data type |
Logical file data type |
|---|
| J |
J, O, E, H, G |
| O |
O, H |
| E |
O, E, H |
| A |
A, O, E, H |
| H |
J, O, E, A, H |
| G |
G, O, J, E |
Note: When the physical file data type is character (A) or hexadecimal
(H), and the logical file data type is DBCS-only (J) or DBCS-either (E), the
physical file field length (columns 30 through 34) must be an even number
greater than or equal to 4.
- DDS treats DBCS key fields as character fields (the data type specified
in position 35 is O).
- DDS uses the EBCDIC collating sequence to sort DBCS data.
- Any key field sequencing keywords that can be used with character fields
can be used with DBCS fields, except the following keywords:
ALTSEQ
DIGIT
ZONE
- Use bracketed-DBCS data anywhere that comments and character
strings are allowed.
- Any bracketed-DBCS field except a field with data type J can be compared
with a character field (data type A).
- A DBCS-graphic field can be compared only with another graphic field.
- The following validity checking keywords can be specified on DBCS fields:
COMP
RANGE
VALUES
- When specifying the VARLEN keyword in a physical file, the minimum allowed
length for the allocated length is 4 for a bracketed-DBCS field. The minimum
allowed length for the allocated length is 1 for a DBCS-graphic field.