Ingres 12.0 | While (QUEL)

Forms-Based Application Development Tools User Guide > Part 5: 4GL > J. Notes for Users of QUEL > While (QUEL)

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While (QUEL)

Repeats a series of statements while a specified condition is true.

QUEL examples are given below. See While for a description of the while statement.

Examples (QUEL Only)

Use the while statement to handle deadlock:

succeed := 0;     /* Set to 1 when and if */
             /* append is successful */
tries := 1;
ingerr := 0;

A:   while succeed = 0 and tries <= 10 do
    ...append statement to try to append
    to database...
    inquire_ingres (ingerr = "errorno");
    if ingerr = 0 then
      /* Append completed successfully */
      succeed := 1;
    elseif ingerr = 4700 then
      /* Error due to deadlock - try again */
      tries := tries + 1;
    else
      endloop A;
    endif;
  endwhile;
if succeed = 1 then
  message "Append completed successfully";
  sleep 3;
else
  message "Append failed";
  sleep 3;
endif;

Last modified date: 08/28/2024