我有这样的表http://pastebin.com/raw.php?i=miEpLUNU 每隔30分钟,我就会插入风向。现在我想做的是我想做这样的事情,但是对于每一天和每个车站。
SELECT DIR_GORYCZKOWA, COUNT(*) AS COUNT_DIR, DATE_FORMAT(DATE_SYSTEM, '%Y-%m-%d') AS DATE
FROM wind_direction
WHERE DATE_SYSTEM BETWEEN '2014-02-19' AND '2014-02-20'
GROUP BY DIR_GORYCZKOWA ORDER BY COUNT_DIR DESC LIMIT 1;
这甚至可能吗?
答案 0 :(得分:0)
试试:
SELECT DIR_GORYCZKOWA, COUNT(*) AS COUNT_DIR, DATE_FORMAT(DATE_SYSTEM, '%Y-%m-%d') AS DATE
FROM wind_direction
GROUP BY DATE(DATE_SYSTEM)
ORDER BY COUNT_DIR DESC LIMIT 1;
答案 1 :(得分:0)
echo_Me的答案是正确的。如果要将返回的数据限制在特定日期范围内,请保留where子句。
返回这些结果的查询是正确的 http://pastebin.com/raw.php?i=QX2MGR5c
这是每天为您提供的每站总数(DIR_GORYCZKOWA)