Live ORACLE

DECLARE

  PROCEDURE Assert

       (assertion  VARCHAR2,

        truth      BOOLEAN)

  IS

  BEGIN

    IF truth IS NULL THEN

      dbms_output.Put_line('Assertion '

                           ||assertion

                           ||' is unknown (NULL)');

    ELSIF truth = true THEN

      dbms_output.Put_line('Assertion '

                           ||assertion

                           ||' is TRUE');

    ELSE

      dbms_output.Put_line('Assertion '

                           ||assertion

                           ||' is FALSE');

    END IF;

  END;

BEGIN

  Assert('2 + 2 = 4',2 + 2 = 4);

 

  Assert('10 > 1',10 > 1);

 

  Assert('10 <= 1',10 <= 1);

 

  Assert('5 BETWEEN 1 AND 10',5 BETWEEN 1 AND 10);

 

  Assert('NULL != 0',NULL != 0);

 

  Assert('3 IN (1,3,5)',3 IN (1,3,5));

 

  Assert('''A'' < ''Z''','A' < 'Z');

 

  Assert('''baseball'' LIKE ''%all%''','baseball' LIKE '%all%');

 

  Assert('''suit'' || ''case'' = ''suitcase''','suit'

                                               ||'case' = 'suitcase');

END;

/

Using Comparison Operators