Specifying a Null Character
If a field is null, you may specify that a character is to be inserted instead of the default blank. For example, to specify that a dash is to be inserted in the field, execute:
SET NULL AS ’-’;
Assume, for example, that a new employee named Nulltest does not yet have a fixed salary. If SET NULL AS ’-’ is specified for the Salary column, data for Nulltest would appear as follows:
DeptNo Name Salary
------ ---------- -----------
700 Nulltest N -