truncate table output
/
-------------------------------------------------------------------------------
-- Example of an anonymous PL/SQL blck
-------------------------------------------------------------------------------
DECLARE                                         -- Anonymous code block
    v_vendor    varchar2(100);                  -- the declaration section
    v_amount    number(9,2);
BEGIN
    SELECT vendor, amount                       -- from the table columns  
      INTO v_vendor, v_amount                   -- into the variables 
      FROM payment
     WHERE payment_num = 1;

    IF v_amount <= 50 THEN 
        INSERT into output VALUES ('payment: $' || v_amount || ' is small');
    ELSE 
        INSERT into output VALUES ('payment: $' || v_amount || ' is sizable');
    END IF;
END;

-------------------------------------------------------------------------------
/
SELECT * from output