[英]Spawning a .lnk windows shortcut with node.js gives "UNKNOWN" error
[英]MySQL gives me "unknown column" error on Windows
我使用 MySQL 在 Node.Js 上執行了以下查詢:
SELECT COUNT(DISTINCT t.uid) AS usersCount, COUNT(*) AS workingDaysCount
FROM (
SELECT d.date, u.id AS uid,
CASE TIMESTAMPDIFF(day, SUBDATE(d.date, WEEKDAY(d.date)), d.date)
WHEN 0 THEN w.monday
WHEN 1 THEN w.tuesday
WHEN 2 THEN w.wednesday
WHEN 3 THEN w.thursday
WHEN 4 THEN w.friday
WHEN 5 THEN w.saturday
WHEN 6 THEN w.sunday
ELSE NULL
END AS working_day
FROM (
SELECT date_range.date
FROM (
SELECT CURDATE() - INTERVAL (sign.a * (a.a + (10 * b.a) + (100 * c.a) + (1000 * e.a) )) DAY AS date
FROM (SELECT -1 AS a UNION ALL SELECT 1) AS sign
CROSS JOIN (SELECT 0 AS a UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS a
CROSS JOIN (SELECT 0 AS a UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS b
CROSS JOIN (SELECT 0 AS a UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS c
CROSS JOIN (SELECT 0 AS a UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS e
ORDER BY date DESC
) date_range
WHERE date_range.Date BETWEEN DATE('2021-06-10') AND DATE('2021-06-10')) d, users u
LEFT OUTER JOIN working_days w ON w.id = (
SELECT id
FROM working_days
WHERE user_id = u.id AND week_start_date <= d.date
ORDER BY week_start_date DESC
LIMIT 1
)
WHERE u.id IN (4)
GROUP BY d.date, u.id
) t
WHERE t.working_day = 1;
在 Linux 服務器上它工作正常,所以我不知道問題出在哪里,但在 Windows 上我有以下錯誤:
#1054 - Unknown column 'd.date' in 'where clause'
我已經查看了代碼並調試了幾個小時,但我沒有找到任何關於此的答案。 請問有人有什么想法嗎?
問題點在於通過逗號和 JOIN 組合笛卡爾。
別名為t
的子查詢看起來像
SELECT ...
FROM (...) d, u LEFT OUTER JOIN working_days w ...
逗號優先級低於 JOIN 優先級,因此查詢是
SELECT ...
FROM (...) d, ( u LEFT OUTER JOIN working_days w ... )
即u
和w
首先加入。 當然,此時子查詢d
不可訪問。
用 CROSS JOIN 替換逗號:
SELECT ...
FROM (...) d
CROSS JOIN u
LEFT OUTER JOIN working_days w ...
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