A formal parameter that SQL uses to indicate the execution
    status of the SQL statement in the procedure. The SQLSTATE
    formal parameter does not require a data type declaration;
    SQL automatically declares SQLSTATE with a CHAR(5) data type.
    However, the calling program module must still declare a
    character variable for the actual parameter that corresponds
    to SQLSTATE. The SQLSTATE parameter must be passed by reference.

    Oracle Rdb recommends that you use the SQLSTATE status parameter
    rather than SQLCODE. SQLSTATE complies with the ANSI/ISO SQL
    standard and SQLCODE may be deprecated in a future release of
    Oracle Rdb.