The following programs demonstrate the use of the RDB$MISSING
    value expression with the STORE clause. The programs store the
    specified values for the fields in the DEGREES relation. In these
    programs, a value for DEGREE_FIELD is not specified; instead, the
    RDB$MISSING value expression is specified. This does not actually
    assign a value to the degree field; RDML marks the DEGREE_FIELD
    as empty and stores nothing in this field.

    Note that the C program uses the pad_string function to read
    in the values for the STORE statement. This function pads the
    values stored in each field with the correct number of trailing
    blanks to ensure that the length of the values stored match the
    text size of the field. For more information on pad_string, see
    Appendix B of the "RDML Reference Manual".

1  –  C Example

    #include <stdio.h>
    DATABASE PERS = FILENAME "PERSONNEL";

    extern void pad_string();

    main()
    {
    READY PERS;
    START_TRANSACTION READ_WRITE;

    STORE D IN DEGREES USING
       pad_string ("76156", D.EMPLOYEE_ID, sizeof(D.EMPLOYEE_ID));
       pad_string ("HVDU" , D.COLLEGE_CODE, sizeof(D.COLLEGE_CODE));
       D.YEAR_GIVEN = 1978;
       pad_string ("BA", D.DEGREE, sizeof(D.DEGREE));
       pad_string (RDB$MISSING(D.DEGREE_FIELD),D.DEGREE_FIELD,
                   sizeof(D.DEGREE_FIELD));
    END_STORE;

    ROLLBACK;
    FINISH;
    }

2  –  Pascal Example

    program store_missing (input,output);
    DATABASE PERS = FILENAME 'PERSONNEL';

    begin
    READY PERS;
    START_TRANSACTION READ_WRITE;

    STORE D IN DEGREES USING
       D.EMPLOYEE_ID := '76156';
       D.COLLEGE_CODE := 'HVDU';
       D.YEAR_GIVEN := 1978;
       D.DEGREE := 'BA';
       D.DEGREE_FIELD := RDB$MISSING(D.DEGREE_FIELD);
    END_STORE;

    ROLLBACK;
    FINISH;
    end.