q2.sql

WITH wscs AS
( SELECT
    sold_date_sk,
    sales_price
  FROM (SELECT
    ws_sold_date_sk sold_date_sk,
    ws_ext_sales_price sales_price
  FROM web_sales) x
  UNION ALL
  (SELECT
    cs_sold_date_sk sold_date_sk,
    cs_ext_sales_price sales_price
  FROM catalog_sales)),
    wswscs AS
  ( SELECT
    d_week_seq,
    sum(CASE WHEN (d_day_name = 'Sunday')
      THEN sales_price
        ELSE NULL END)
    sun_sales,
    sum(CASE WHEN (d_day_name = 'Monday')
      THEN sales_price
        ELSE NULL END)
    mon_sales,
    sum(CASE WHEN (d_day_name = 'Tuesday')
      THEN sales_price
        ELSE NULL END)
    tue_sales,
    sum(CASE WHEN (d_day_name = 'Wednesday')
      THEN sales_price
        ELSE NULL END)
    wed_sales,
    sum(CASE WHEN (d_day_name = 'Thursday')
      THEN sales_price
        ELSE NULL END)
    thu_sales,
    sum(CASE WHEN (d_day_name = 'Friday')
      THEN sales_price
        ELSE NULL END)
    fri_sales,
    sum(CASE WHEN (d_day_name = 'Saturday')
      THEN sales_price
        ELSE NULL END)
    sat_sales
  FROM wscs, date_dim
  WHERE d_date_sk = sold_date_sk
  GROUP BY d_week_seq)
SELECT
  d_week_seq1,
  round(sun_sales1 / sun_sales2, 2),
  round(mon_sales1 / mon_sales2, 2),
  round(tue_sales1 / tue_sales2, 2),
  round(wed_sales1 / wed_sales2, 2),
  round(thu_sales1 / thu_sales2, 2),
  round(fri_sales1 / fri_sales2, 2),
  round(sat_sales1 / sat_sales2, 2)
FROM
  (SELECT
    wswscs.d_week_seq d_week_seq1,
    sun_sales sun_sales1,
    mon_sales mon_sales1,
    tue_sales tue_sales1,
    wed_sales wed_sales1,
    thu_sales thu_sales1,
    fri_sales fri_sales1,
    sat_sales sat_sales1
  FROM wswscs, date_dim
  WHERE date_dim.d_week_seq = wswscs.d_week_seq AND d_year = 2001) y,
  (SELECT
    wswscs.d_week_seq d_week_seq2,
    sun_sales sun_sales2,
    mon_sales mon_sales2,
    tue_sales tue_sales2,
    wed_sales wed_sales2,
    thu_sales thu_sales2,
    fri_sales fri_sales2,
    sat_sales sat_sales2
  FROM wswscs, date_dim
  WHERE date_dim.d_week_seq = wswscs.d_week_seq AND d_year = 2001 + 1) z
WHERE d_week_seq1 = d_week_seq2 - 53
ORDER BY d_week_seq1;