exception handling

Program code that checks for exceptions and performs recovery actions in the event they occur. By default, 4GL performs the following exception handling: run-time errors--terminate the program; SQL NOTFOUND--set status to NOTFOUND and continue execution; warnings--continue execution; Interrupt (or Quit) key--terminate program. The developer can change the default exception handling for these first three types of exceptions with the WHENEVER statement: run-time errors --WHENEVER ERROR; SQL NOTFOUND--WHENEVER NOT FOUND; warnings--WHENEVER WARNING. The 4GL DEFER statement changes handling of the Interrupt and Quit keys.

See also error handling, Interrupt key, program execution, Quit key, status, warning.