Question

我有一个sqlite3表，记录我的加热系统的状态和每30秒一次。该表看起来像这样

TABLE CLIMATESYSTEM (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    Timestamp INT,
    FAN INT,
    SYSTEM INT
);

timestamp是自python

中的epoch（（int）time.time）以来的秒数

表中的几行看起来像这样

5577|1452049280|1|1
5578|1452049339|1|1
5579|1452049399|1|1
5580|1452049459|1|1
5581|1452049520|0|0
5582|1452049580|0|0
5583|1452049644|1|1
5584|1452049700|1|1
5585|1452049760|1|1
5586|1452049820|0|0

我要做的是计算状态转换从开启（1）到关闭（0）与下一次从关闭转换为开启之间的秒数。

示例计算＃5577和＃5581之间的秒数 - ＆gt;添加到TIME_SYS_ON

示例计算＃5581和＃5583之间的秒数 - ＆gt;添加到TIME_SYS_OFF

我打算做的是测量我的加热系统运行的24小时内的总时间

关于起点的任何想法？

由于

Answer 1

首先，查找每一行的下一个时间戳：

SELECT Timestamp,
       (SELECT MIN(Timestamp)
        FROM ClimateSystem AS CS2
        WHERE CS2.Timestamp > ClimateSystem.Timestamp
       ) AS NextTimestamp,
       System
FROM ClimateSystem;

然后用它来计算每个区间的长度：

SELECT NextTimestamp - Timestamp,
       System
FROM (SELECT Timestamp,
             (SELECT MIN(Timestamp)
              FROM ClimateSystem AS CS2
              WHERE CS2.Timestamp > ClimateSystem.Timestamp
             ) AS NextTimestamp,
             System
      FROM ClimateSystem);

然后根据需要添加过滤器：

SELECT SUM(NextTimestamp - Timestamp),
       System
FROM (SELECT Timestamp,
             (SELECT MIN(Timestamp)
              FROM ClimateSystem AS CS2
              WHERE CS2.Timestamp > ClimateSystem.Timestamp
             ) AS NextTimestamp,
             System
      FROM ClimateSystem)
WHERE Timestamp BETWEEN :StartOfDay AND :EndOfDay
GROUP BY System;

SQL行状态更改之间的时间

1 个答案: