[英]MySQL Group Epoch Timestamp by Every 15 Minutes
我有一個數據庫,它以相當高的頻率收集一些數據並記錄每個條目的時間戳(存儲為紀元時間,而不是 mysql 日期時間)。 例如
timestamp rssi sender
-------------------------------------------
1592353967.171600 -67 9EDA3DBFFE15
1592353967.228000 -67 9EDA3DBFFE15
1592353967.282900 -62 E2ED2569BE2
1592353971.892600 -67 9EDA3DBFFE15
1592353973.962900 -61 2ADE2E4597B2
...
我的目標是能夠在 15 分鍾的時間間隔內獲得所有行的計數,經過研究可以使用GROUP BY
獲得。 理想情況下,最終的 output 看起來像這樣
timestamp count
------------------------------
1592352000 (8:00pm EST) 38
1592352900 (8:15pm EST) 22
1592353800 (8:30pm EST) 0 <----- Important, must include periods with 0 entries
1592354700 (8:45pm EST) 61
...
我在這里主要遇到兩件事:1.能夠在結果中顯示時間戳間隔2.在一個時間段內顯示0行的間隔
我目前的嘗試如下,它在正確的軌道上,因為那里的時間段內的數據實際上是正確的
Showing rows 0 - 23 (24 total, Query took 0.0264 seconds.)
SELECT count(*) AS total, MINUTE(FROM_UNIXTIME(timestamp)) AS minute
FROM requests
WHERE timestamp >= 1592352000 AND timestamp < (1592352000 + 3600)
GROUP BY MINUTE(FROM_UNIXTIME(timestamp))
total minute
55 32
89 33
64 34
55 35
87 36
82 37
90 38
69 39
74 40
47 41
89 42
53 43
71 44
87 45
72 46
83 47
86 48
83 49
113 50
76 51
77 52
88 53
81 54
28 55
這個數據是正確的,但是這里沒有顯示一些時間段(這個小時的前 30 分鍾沒有數據,因此第一minute
條目從 32 開始)。 還嘗試通過使用每 15 分鍾獲取一次
SELECT count(*) AS total, MINUTE(FROM_UNIXTIME(timestamp)) AS minute
FROM requests
WHERE timestamp >= 1592352000 AND timestamp < (1592352000 + 3600)
GROUP BY MINUTE(FROM_UNIXTIME(timestamp)) DIV 15
#1055 - Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'wave_master.requests.timestamp' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
任何幫助將不勝感激。
您可以使用“數字”表生成一小時內的 15 分鍾周期 (0-3),然后將其LEFT JOIN
到您的計數中,按 15 分鍾周期分組,使用COALESCE
將NULL
值替換為 0:
SELECT periods.period * 900 + 1592352000 AS timestamp,
FROM_UNIXTIME(periods.period * 900 + 1592352000) AS time,
COALESCE(counts.total, 0) AS total
FROM (
SELECT 0 period
UNION ALL SELECT 1
UNION ALL SELECT 2
UNION ALL SELECT 3
) periods
LEFT JOIN (
SELECT (timestamp - 1592352000) DIV 900 AS period,
COUNT(*) AS total
FROM requests
WHERE timestamp >= 1592352000 AND timestamp < 1592352000 + 3600
GROUP BY period
) counts ON counts.period = periods.period
Output (對於您問題中的數據以及其他幾個值):
timestamp time total
1592352000 2020-06-17 00:00:00 1
1592352900 2020-06-17 00:15:00 1
1592353800 2020-06-17 00:30:00 5
1592354700 2020-06-17 00:45:00 0
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