1  ROLLBACK
   Terminates a transaction and undoes all changes that have been
   made to the database since the program's most recent START_
   TRANSACTION statement. The ROLLBACK statement also closes all
   open streams and releases all locks. The ROLLBACK statement
   affects both data manipulation and data definition statements.

   Example:

   RDO> START_TRANSACTION READ_WRITE
   RDO> DEFINE FIELD LOCATION_CODE DATATYPE TEXT SIZE 5.
   RDO> ! Oops, wrong size!
   RDO> ROLLBACK
   RDO> START_TRANSACTION READ_WRITE
   RDO> DEFINE FIELD LOCATION_CODE DATATYPE TEXT SIZE 7.
   RDO> COMMIT
 

2  Format

 (B)0ROLLBACK qqwqqqqqqqqqqqqqqqqqqqqqqq>qqqqqqqqqqwqwqqqqqqqqqqqqqqqqwqqq>
            mq> (TRANSACTION_HANDLE qq> var) qqj mqq> on-error qqqj

 

3  TRANSACTION_HANDLE
   A keyword followed by a host language variable. A transaction
   handle identifies each instance of a transaction. If you do not
   declare the transaction handle explicitly, Oracle Rdb attaches an
   internal identifier to the transaction.

   In Callable RDO, use !VAL as a marker for host language
   variables.

   You can put parentheses around the host language variable name.

   Normally, you do not need to use this argument. The ability to
   declare a transaction handle is provided for compatibility with
   other database products and future releases of Oracle Rdb.
 

3  on-error
   The ON ERROR clause, which specifies a host language statement to
   be performed if an Oracle Rdb error occurs. For more details, request
   HELP on ON_ERROR.
 

2  More
   If you have invoked a database, you have the necessary privileges
   to use the ROLLBACK statement.
 

2  Example
   Roll back changes made during a transaction with a COBOL program:

   GET-ID-NUMBER.
         DISPLAY "Enter employee ID number:  "
            WITH NO ADVANCING.
         ACCEPT EMPLOYEE-ID.
   CHANGE-SALARY.
         DISPLAY "Enter new salary amount:  "
            WITH NO ADVANCING.
         ACCEPT SALARY-AMOUNT.

   &RDB&   START_TRANSACTION READ_WRITE
   &RDB&    FOR S IN SALARY_HISTORY WITH
   &RDB&       E.EMPLOYEE-ID = EMPLOYEE-ID
   &RDB&          MODIFY USING
   &RDB&             S.SALARY-AMOUNT = SALARY-AMOUNT
   &RDB&          END-MODIFY
   &RDB&   END-FOR

         DISPLAY EMPLOYEE-ID, SALARY-AMOUNT.
         DISPLAY "Is this figure correct? [Y or N]  "
            WITH NO ADVANCING.
         ACCEPT ANSWER.
         IF ANSWER = "Y" THEN
   &RDB&   COMMIT
         ELSE
   &RDB&   ROLLBACK
           DISPLAY "Please enter the new salary amount again."
           GO TO CHANGE-SALARY.