mysql中生成时间维度表
利用mysql常用日期函数生成时间维度表，效率最高，最简单，无需其他的一些工具支持。生成结果示例如下图：
# time span
SET @d0 = "2012-01-01";
SET @d1 = "2012-12-31";
SET @date = date_sub(@d0, interval 1 day);
# set up the time dimension table
DROP TABLE IF EXISTS time_dimension;
CREATE TABLE `time_dimension` (
`date` date DEFAULT NULL,
`id` int NOT NULL,
`y` smallint DEFAULT NULL,
`m` smallint DEFAULT NULL,
`d` smallint DEFAULT NULL,
`yw` smallint DEFAULT NULL,
`w` smallint DEFAULT NULL,
`q` smallint DEFAULT NULL,
`wd` smallint DEFAULT NULL,
`m_name` char(10) DEFAULT NULL,
`wd_name` char(10) DEFAULT NULL,
PRIMARY KEY (`id`)
);
# populate the table with dates
INSERT INTO time_dimension
SELECT @date := date_add(@date, interval 1 day) as date,
# integer ID that allowsimmediate understanding
date_format(@date, "%Y%m%d")as id,
year(@date) as y,
month(@date) as m,
day(@date) as d,
date_format(@date, "%x")as yw,
week(@date, 3) as w,
quarter(@date) as q,
weekday(@date)+1 as wd,
monthname(@date) as m_name,
dayname(@date) as wd_name
FROM T
WHERE date_add(@date, interval 1 day) <= @d1
ORDER BY date
;
神秘的表T，仅仅需要有多于你需要生成日期的记录数即可。思路是从T表选择多行数据，同时生成对应的日期字段。
