q40.sql

SELECT
  w_state,
  i_item_id,
  sum(CASE WHEN (cast(d_date AS DATE) < cast('2000-03-11' AS DATE))
    THEN cs_sales_price - coalesce(cr_refunded_cash, 0)
      ELSE 0 END) AS sales_before,
  sum(CASE WHEN (cast(d_date AS DATE) >= cast('2000-03-11' AS DATE))
    THEN cs_sales_price - coalesce(cr_refunded_cash, 0)
      ELSE 0 END) AS sales_after
FROM
  catalog_sales
  LEFT OUTER JOIN catalog_returns ON
                                    (cs_order_number = cr_order_number
                                      AND cs_item_sk = cr_item_sk)
  , warehouse, item, date_dim
WHERE
  i_current_price BETWEEN 0.99 AND 1.49
    AND i_item_sk = cs_item_sk
    AND cs_warehouse_sk = w_warehouse_sk
    AND cs_sold_date_sk = d_date_sk
    AND d_date BETWEEN (cast('2000-03-11' AS DATE) - INTERVAL '30' day)
  AND (cast('2000-03-11' AS DATE) + INTERVAL '30' day)
GROUP BY w_state, i_item_id
ORDER BY w_state, i_item_id
LIMIT 100;