ROLLBACK

General Format

ROLLBACK TRANSACTION

General rules

Each system's native mechanism for transaction management is invoked.

1.	When ROLLBACK is enabled in the FILE-CONTROL entry for a file, the record and file locking rules are extended for that file. ROLLBACK verb removes these locks.

2.	If an Indexed or Relative data file is CLOSEd during a transaction the CLOSE will wait for the completed ROLLBACK.

3.	If an abnormal end of program occurs, an automatic rollback is initiated.

Examples

 

*> This sample will work only with a file system that supports transactions *> The select should include lock clause with rollback: lock automatic with rollback      start transaction    display "Customer to apply 10% discount? "    accept ws-cust-code    move ws-cust-code to cust-code    read customers          invalid key display message "Customer not found"                     rollback                     exit paragraph    end-read    accept ws-date from date    move ws-date to cust-last-date-discount    rewrite cust-rec    move ws-cust-code to inv-cust-code    start invoices key = inv-cust-code          invalid key set end-of-invoices to true          not invalid key set end-of-invoices to false    end-start    perform until end-of-invoices      read invoices next at end exit perform           not at end                if inv-cust-code not = ws-cust-code                  exit perform               end-if      end-read      if inv-paid-status = "N"         move 10 to inv-discount         rewrite invoice-rec      end-if    end-perform    display "Changes applied, confirm Commit: (Y/N)"    accept apply-commit    if apply-commit = "Y"       commit *> All changes are definitely applied    else       rollback *> All changes get undone    end-if.