The following programs demonstrate the use a host variable value
    expression as a transaction handle. These programs declare the
    host variable, EMP_UPDATE. The programs use EMP_UPDATE to qualify
    the transaction in the START_TRANSACTION expression, the record
    selection expression, and the COMMIT statement. The record
    selection expression modifies the record with the specified ID
    number in the EMPLOYEES relation. The COMMIT statement, also
    qualified with the transaction handle, ensures that the modified
    record is stored in the database.

    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".