我在下面的最后一部分“递归”中挣扎。当然,我可以使用 C# 循环访问数据库中的每一天的 TimestampOrigin。这将意味着数百次相同的查询。但是使用“带递归”的一个查询可能是可能的。
测试数据:
CREATE TABLE tblData(
Id INT, ComputerName TEXT, TimestampOrigin TEXT, Timestamp TEXT, Number INT
);
DELETE FROM tblData;
INSERT INTO tblData VALUES (1, "Computer1", '2021-02-10 12:00:00', '2021-02-27 12:00:00', 35);
INSERT INTO tblData VALUES (2, "Computer2", '2021-02-10 12:00:00', '2021-02-27 12:00:00', 24);
INSERT INTO tblData VALUES (3, "Computer3", '2021-02-09 12:00:00', '2021-02-26 12:00:00', 23);
INSERT INTO tblData VALUES (3, "Computer4", '2021-02-09 12:00:00', '2021-02-26 12:00:00', null);
INSERT INTO tblData VALUES (4, "Computer5", '2021-02-08 12:00:00', '2021-02-25 12:00:00', 7);
INSERT INTO tblData VALUES (5, "Computer6", '2021-02-08 12:00:00', '2021-02-25 12:00:00', 0);
INSERT INTO tblData VALUES (7, "Computer7", '2021-02-07 12:00:00', '2021-02-24 12:00:00', 9);
按 TimestampOrigin 分组的查询:
SELECT DATE(TimestampOrigin) AS TimestampOrigin,
SUM(CASE WHEN Number < 1 THEN 1 ELSE 0 END) AS Less1,
SUM(CASE WHEN Number >= 0 AND Number < 10 THEN 1 ELSE 0 END) AS Less10,
SUM(CASE WHEN Number >= 10 AND Number < 25 THEN 1 ELSE 0 END) AS Less25
FROM tblData WHERE Number NOT NULL GROUP BY DATE(TimestampOrigin) ORDER BY TimestampOrigin DESC
我每天需要的是当前到时间戳的总和,即当天+17天。以 2021-02-08 天为例,时间戳来源为 2021-02-08 到 2021-02-08 +17 天的所有行的总和(时间戳列)。不知道是否真的需要 TimestampOrigin +17 天的中午时间的额外列 Timestamp。但是随着时间的推移查询是我在项目一开始就创建它的原因。
SELECT DATE(TimestampOrigin) AS TimestampOrigin,
SUM(CASE WHEN Number < 1 THEN 1 ELSE 0 END) AS Less1,
SUM(CASE WHEN Number >= 0 AND Number < 10 THEN 1 ELSE 0 END) AS Less10,
SUM(CASE WHEN Number >= 10 AND Number < 25 THEN 1 ELSE 0 END) AS Less25
FROM tblData WHERE Number NOT NULL AND DATE(TimestampOrigin) >= DATE('2021-02-08') AND DATE(TimestampOrigin) <= DATE('2021-02-08', '+17 day')
我没有每天执行数百次上述查询并求和,而是认为“使用递归”是正确的方法“。但到目前为止还不能让它工作。在哪里添加 17 天?
WITH RECURSIVE cte AS (
SELECT Id, ComputerName, Timestamp, DATE(Timestamp,'+1 day') totime, Number, TimestampOrigin
FROM tblData
UNION ALL
SELECT Id, ComputerName, DATE(Timestamp,'+1 day'), DATE(totime,'+1 day'), Number, TimestampOrigin
FROM cte
WHERE Number NOT NULL AND DATE(Timestamp,'+1 day') < DATE('2021-02-11')
)
SELECT DATE(TimestampOrigin),
SUM(CASE WHEN Number < 1 THEN 1 ELSE 0 END) AS Less1,
SUM(CASE WHEN Number >= 0 AND Number < 10 THEN 1 ELSE 0 END) AS Less10,
SUM(CASE WHEN Number >= 10 AND Number < 25 THEN 1 ELSE 0 END) AS Less25
FROM cte GROUP BY DATE(TimestampOrigin) ORDER BY DATE(TimestampOrigin) DESC
预期结果将是(就像我在测试数据中的 4 天中的每一天运行上述查询时一样):