RFM 分析 - 价值不断变化

Question

得到以下查询。

SELECT
    customer_id,
    NTILE(5) OVER (ORDER BY MAX(oms_order_date)) AS r_score
FROM 
    mdwh.us_raw.l_dmw_order_report
WHERE 
    quantity_ordered > 0
    AND customer_id IS NOT NULL
    AND customer_id != ('')
    AND UPPER(line_status) NOT IN ('','RETURN', 'CANCELLED')
    AND UPPER(item_description_1) NOT IN ('','FREIGHT', 'RETURN LABEL FEE', 'VISIBLE STITCH')
    AND (quantity_ordered * unit_price_amount) > 0
    AND extended_amount < 1000 --NO BULK ORDERS
    AND oms_order_date BETWEEN '2020-01-01' AND '2020-01-01'
    AND SUBSTRING(upc,1,6) IN (SELECT item_code FROM item_master_zs WHERE new_division BETWEEN '11' AND '39')
GROUP BY
    customer_id
ORDER BY
    customer_id

我在这里所做的只是，在某些条件下，给我唯一的客户 ID，然后将他们的最新购买日期分成五分位数，并在第二列中为我提供分数。但是每次我运行查询时，r_score 值都会不断变化？我究竟做错了什么..？这是表格的外观（同样，r_score 值不断变化）：

Answer 1

ntile() 的问题在于，它通过在不同的组中放置相同的值来确保组的大小完全相同。

因此，我通常使用rank()手动进行计算：

ceil(rank() over (order by max(oms_order_date)) * 5.0 /
     count(*) over ()
    ) as r_score

如果你使用row_number()，你会得到ntile()的等价物。

如果你想使用ntile()，你可以使用额外的order by键，这样排序键是唯一的。

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2/17/20 下午 5:18 编辑

这是我正在使用的新代码：

SELECT
    customer_id,
    CEIL(RANK() OVER (ORDER BY MAX(oms_order_date)) * 5 / COUNT(*) OVER ()) AS r_score,
    CEIL(RANK() OVER (ORDER BY COUNT(client_web_order_number)) * 5 / COUNT(*) OVER ()) AS f_score,
    CEIL(RANK() OVER (ORDER BY AVG(extended_amount)) * 5 / COUNT(*) OVER ()) AS m_score,
    (r_score || f_score || m_score) AS rfm_score
FROM 
    mdwh.us_raw.l_dmw_order_report t1
WHERE 
    quantity_ordered > 0
    AND customer_id IS NOT NULL
    AND customer_id != ('')
    AND oms_order_date IS NOT NULL
    AND UPPER(line_status) NOT IN ('','RETURN', 'CANCELLED')
    AND UPPER(item_description_1) NOT IN ('','FREIGHT', 'RETURN LABEL FEE', 'VISIBLE STITCH')
    AND (quantity_ordered * unit_price_amount) > 0
    AND extended_amount < 1000 --NO BULK ORDERS
    AND oms_order_date BETWEEN '2020-01-01' AND '2020-01-10'
    AND SUBSTRING(upc,1,6) IN (SELECT item_code FROM item_master_zs WHERE new_division BETWEEN '11' AND '39')
GROUP BY
    customer_id
ORDER BY
    customer_id

现在的问题是我得到了一些带有空白 r_score 的行，最大值是 4 而不是 5..