Question

我有一个简单的日志表：

id | user_id | value | created_at | updated_at

假设用户在一个月内进行了多次输入。其中一些条目是连续几天。即周一，周二，周三，周四，但随后她会跳过一天并且不会进入另一个条目，直到坐下。我希望能够说她已经连续4天登录了。我不想在服务器端执行此操作，因为这个表很容易就是数百万个日志条目，所以我开始寻找查询数据库的方法。

经过几个小时，我觉得sequelize并没有很好地处理这个问题，转向原始的sql。我发现，这不是我自己的，这个问题：

WITH

  -- This table contains all the distinct date 
  -- instances in the data set
  dates(date) AS (
    SELECT DISTINCT CAST(created_at AS DATE)
    FROM plan_activity_logs
    WHERE user_id = ${user}
  ),

  -- Generate "groups" of dates by subtracting the
  -- date's row number (no gaps) from the date itself
  -- (with potential gaps). Whenever there is a gap,
  -- there will be a new group
  groups AS (
    SELECT
      ROW_NUMBER() OVER (ORDER BY date) AS rn,
      dateadd(day, -ROW_NUMBER() OVER (ORDER BY date), date) AS grp,
      date
    FROM dates
  )
SELECT
  COUNT(*) AS consecutiveDates,
  MIN(date) AS minDate,
  MAX(date) AS maxDate
FROM groups
GROUP BY grp
ORDER BY 1 DESC, 2 DESC

如果我正确地理解它，那就完全符合我的要求，但是当它被执行时，sequelize会抛出一个错误：

 "sqlMessage": "You have an error in your SQL syntax; 
      check the manual that corresponds to your MySQL server
      version for the right syntax to use near 
     'dates(date) AS (
    SELECT DISTINCT CAST(created_at AS DATE)
    ' at line 1",

我不太了解sql，但我很确定with语句没有错，所以我想知道这是不是一个sequelize的怪癖我不理解？

如何使用sequelize来获取条目的连续日期数？

0 个答案: