DECODE (argument1,
	      ‘value 1’, ‘value 1’,
	      DECODE ( argument2, 
		       ‘value 2’, ‘value 2’,
		       DECODE ( argument3,
			        ‘value3’, ‘value3’,
				‘def_value’)

IF argument1 = value1 THEN
	'VALUE1'
ELSE
	IF argument2 = value2 THEN 
		'VALUE2'
	ELSE
		IF argument3 = argument3 THEN
			'Value3'
		ELSE
			'def_Value'
		END IF;
	END IF;
END IF;

CASE
WHEN argument1 = value1 THEN 'value1'
ELSE
	CASE
	WHEN argument2 = value2 THEN 'value2'
	ELSE
		CASE 
		WHEN argument3 = argument3 THEN 'value3'
		ELSE 'def_value'
		END
	END
END

CASE
WHEN argument = value1 THEN 'value1'
WHEN Argument2 = value2  THEN 'value 2'
WHEN argument3 = value3 then 'value 3'
ELSE 'def_value'
END

DECODE ( substr(bottled_products, 1, 10,
		‘coke’, ‘coke’,
		‘pepsi’, ‘pepsi’,
		DECODE (  substr(bottled_products, 11, 20),
				‘snapple’, ‘snapple’,
				DECODE ( substr(bottled_products, 21, 30),
					‘gatorade, ‘gatorade’,
					‘powerade’)

CASE 
WHEN substr(bottled_products, 1, 10) = ‘coke’ THEN ‘coke
WHEN substr(bottled_products, 1, 10) = ‘pepsi’ THEN ‘pepsi’
WHEN substr(bottled_products, 11, 20) = ‘snapple’ THEN ‘snapple’
WHEN substr(bottled_products, 21, 30) = ‘gatorade’ THEN ‘gatorade’
ELSE powerade
END