DECLARE

  l_budget NUMBER := 1000000;

   -- cursor

  CURSOR c_sales IS

  SELECT  *  FROM sales  

  ORDER BY total DESC;

   -- record    

   r_sales c_sales%ROWTYPE;

BEGIN

​

  -- reset credit limit of all customers

  UPDATE customers SET credit_limit = 0;

​

  OPEN c_sales;

​

  LOOP

    FETCH  c_sales  INTO r_sales;

    EXIT WHEN c_sales%NOTFOUND;

​

    -- update credit for the current customer

    UPDATE 

        customers

    SET  

        credit_limit = 

            CASE WHEN l_budget > r_sales.credit 

                        THEN r_sales.credit 

                            ELSE l_budget

            END

    WHERE 

        customer_id = r_sales.customer_id;

​

    --  reduce the budget for credit limit

    l_budget := l_budget - r_sales.credit;

​

    DBMS_OUTPUT.PUT_LINE( 'Customer id: ' ||r_sales.customer_id || 

' Credit: ' || r_sales.credit || ' Remaining Budget: ' || l_budget );

​

    -- check the budget

    EXIT WHEN l_budget <= 0;

  END LOOP;

​

  CLOSE c_sales;

END;

Code language: SQL (Structured Query Language) (sql)