Use BOOLEAN type variable : Boolean « PL SQL Data Types « Oracle PL/SQL Tutorial






SQL>
SQL> SET ECHO ON
SQL> SET SERVEROUTPUT ON
SQL>
SQL> DECLARE
  2    error_flag  BOOLEAN := false;
  3
  4  BEGIN
  5    DBMS_OUTPUT.PUT_LINE('We are going to count from 100 to 1000.');
  6
  7    DECLARE
  8      hundreds_counter  NUMBER(1,-2);
  9    BEGIN
 10      hundreds_counter := 100;
 11      LOOP
 12        DBMS_OUTPUT.PUT_LINE(hundreds_counter);
 13        hundreds_counter := hundreds_counter + 100;
 14        IF hundreds_counter > 1000 THEN
 15          EXIT;
 16        END IF;
 17       END LOOP;
 18    EXCEPTION
 19    WHEN OTHERS THEN
 20      error_flag := true;
 21    END;
 22
 23    IF error_flag THEN
 24      DBMS_OUTPUT.PUT_LINE('Sorry, I cannot count that high.');
 25     ELSE
 26      DBMS_OUTPUT.PUT_LINE('Done.');
 27    END IF;
 28  END;
 29  /
We are going to count from 100 to 1000.
100
200
300
400
500
600
700
800
900
Sorry, I cannot count that high.

PL/SQL procedure successfully completed.

SQL>
SQL>








21.13.Boolean
21.13.1.BOOLEAN
21.13.2.Boolean literals
21.13.3.Boolean variables can be assigned either directly by using values TRUE, FALSE, or NULL or as the results of logical expressions
21.13.4.How to assign a TRUE value to a variable of type boolean
21.13.5.Use BOOLEAN type variable
21.13.6.Use 'and' to connect two boolean expressions
21.13.7.Demonstrates the effects of NULLs on Boolean expressions
21.13.8.Boolean type parameter
21.13.9.Exit when a boolean conditioin
21.13.10.Logic operator and boolean value