When an externally described file contains null-capable fields and the
ALWNULL(*NO) keyword is specified on a control specification, the following
conditions apply:
- A record containing null values retrieved from a file will cause a data
mapping error and an error message will be issued.
- Data in the record is not accessible and none of the fields in the record
can be updated with the values from the input record containing null values.
- With this option, you cannot place null values in null-capable fields
for updating or adding a record. If you want to place null values in null-capable
fields, use the ALWNULL(*USRCTL) option.