The property isNullable indicates
whether the field can be set to NULL. The property is available only for primitive
fields in a non-fixed record or for structure fields in an SQL record. Valid
values are no (the default) and yes.
If a given field in an SQL record is nullable, the following features are
available:
- The field can accept a NULL value from an SQL database table.
- A set statement can null the field, as described
in set. The effect of setting a field to null is also to initialize
the field, as described in Data initialization.
- An if statement can test whether the field is
set to null.
If you are generating code with the build descriptor option
itemsNullable set
to YES, the effect is as follows:
- All primitive variables are nullable, whether they are standalone variables
or fields in non-fixed records
- All structure fields in SQL records are nullable