增长率

使用 SQL 分析业务数据

Michel Semaan

Data Scientist

差值（Delta）- 查询

WITH maus AS (
  SELECT
    DATE_TRUNC('month', order_date) :: DATE AS delivr_month,
    COUNT(DISTINCT user_id) AS mau
  FROM orders
  GROUP BY delivr_month),

  maus_lag AS (
  SELECT
    delivr_month,
    mau,
    COALESCE(
      LAG(mau) OVER (ORDER BY delivr_month ASC),
    1) AS last_mau
  FROM maus)

差值（Delta）- 结果

查询

WITH maus AS (...),
  maus_lag AS (...)

SELECT
  delivr_month,
  mau,
  mau - last_mau AS mau_delta
FROM maus_lag
ORDER BY delivr_month
LIMIT 3;

结果

delivr_month  mau  mau_delta
------------  ---  ---------
2018-06-01    123  1
2018-07-01    226  103
2018-08-01    337  111

差值（Delta）- 注意事项

原始、绝对数值
只显示变量的三种状态之一
- 若 $\delta \lt 0$ 则下降
- 若 $\delta = 0$ 则持平
- 若 $\delta \gt 0$ 则上升

增长率 - 概览

增长率：相对初始值，衡量变量随时间变化的百分比
公式：$\frac{当前值-前一值}{前一值}$
示例：$\frac{67 - 50}{50} = 0.34 = 34\% $

增长率 - 查询

查询

WITH maus AS (...),
  maus_lag AS (...)

SELECT
  delivr_month,
  mau,
  ROUND(
    (mau - last_mau) :: NUMERIC / last_mau,
  2) AS growth
FROM maus_lag
ORDER BY delivr_month
LIMIT 3;

结果

delivr_month  mau  growth
------------  ---  ------
2018-06-01    123  122.00
2018-07-01    226  0.84
2018-08-01    337  0.49

增长

使用 SQL 分析业务数据