Programming Guide


Tests whether a field is null

int sm_null(int field_number);
int sm_e_null(char *field_name, int element);
int sm_i_null(char *field_name, int occurrence);
int sm_n_null(char *field_name);
int sm_o_null(int field_number, int occurrence);

field_name, field_number
Specifies the field to test.

The element in field_name to test.

The occurrence in the specified field to test.



Use sm_null to test whether a field's value is null or not. This function checks whether a field's null_field property is set to PV_YES; if it is, sm_null gets the field's null indicator and compares it to the field's value.

You can specify the field's null indicator string through the message file and/or the field's Null Text property.