Field mapping rules
File Manager uses the rules shown in Field mapping rules to determine if a
given “from” field can be mapped to a given “to” field.
“Yes” indicates that the mapping is valid. “No”
indicates that the mapping is invalid.
“From” field | “To” field | ||
---|---|---|---|
Alphanumeric | Numeric | Floating-point | |
Alphanumeric1 | Yes | Yes2 | Yes2 |
Numeric integer3 | Yes | Yes | Yes |
Numeric non-integer4 | No | Yes | Yes |
Floating-point5 | No | Yes | Yes |
Note:
|
These rules describe
how a validly mapped “from” field
is moved to a “to” field. When the “to” field is:
- Alphanumeric
- The data is aligned at the leftmost
character position and, if
necessary, truncated or padded with spaces at the right. The COBOL
JUSTIFIED clause, if specified, is ignored.
If the “from” field is a numeric field, the absolute (unsigned) value is used. If the field is defined as signed and the sign occupies a separate character, that character is not moved, and the sending item is considered to be one less character than the actual size.
- Numeric
- The data is aligned on the
assumed decimal point and, if necessary,
truncated or padded with zeros. If an assumed decimal point is not
explicitly specified in the field definition, one is assumed immediately
to the right of the field.
For a negative number when the “from” field is signed numeric, the data is moved as if both the “from” field and “to” field were described as signed.
When the “from” field is alphanumeric, the data is moved as if the “from” field were described as a signed numeric.
- Internal Floating-Point
- A decimal point is assumed immediately to the left of the field. The data is aligned then on the leftmost digit position following the decimal point, with the exponent adjusted accordingly.
- External Floating-Point
- The data is aligned on the leftmost digit position, and the exponent adjusted accordingly.