形象设计,seo的站外优化流程,wordpress 文章宽度,建网站有什么要注意的文章目录 生成最近24小时整点生成最近30天生成最近12个月 生成最近24小时整点
SELECT-- 每向下推1行, i比上次减去1b.*, i.*,DATE_FORMAT( DATE_SUB( NOW(), INTERVAL ( -( i : i - 1 ) ) HOUR ), %Y-%m-%d %H:00 ) AS time
FROM-- 目的是生成12行数据( SELECTa FROM( SELECT… 文章目录 生成最近24小时整点生成最近30天生成最近12个月 生成最近24小时整点
SELECT-- 每向下推1行, i比上次减去1b.*, i.*,DATE_FORMAT( DATE_SUB( NOW(), INTERVAL ( -( i : i - 1 ) ) HOUR ), %Y-%m-%d %H:00 ) AS time
FROM-- 目的是生成12行数据( SELECTa FROM( SELECT 1 AS a UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 ) AS aJOIN ( SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 ) AS b ON 1 ) AS b,-- 先给1个默认的值( SELECT i : 1 ) AS i -- 每次跟主表连接1次, 都会动态计算列select中的值就跟2张普通的表按条件连接起来,然后取表中的字段一样,只不过这里取的是i,而i属于会话变量而已
-- ORDER BY time 生成最近30天
同理往前推30天
SELECTDATE_FORMAT( DATE_SUB( NOW(), INTERVAL ( -( i : i - 1 ) ) DAY ), %Y-%m-%d ) AS time
FROM(SELECTa FROM( SELECT 1 AS a UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 ) AS aJOIN ( SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 ) AS b ON 1 ) AS b,( SELECT i : 1 ) AS i
ORDER BY time 生成最近12个月
SELECT DATE_FORMAT(CURDATE(), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 1 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 2 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 3 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 4 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 5 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 6 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 7 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 8 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 9 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 10 MONTH), %m) AS month
UNION SELECT DATE_FORMAT((CURDATE() - INTERVAL 11 MONTH), %m) AS month
