mysql.help_topic生成序列的方法实现

SELECT
	DATE( DATE_ADD( '2022-05-01', INTERVAL @s DAY ) ) AS date,
	'异常总条数' as e_name,
	 @s := @s + 1 AS `index`
FROM
	mysql.help_topic,
	( SELECT @s := 0 ) temp 
WHERE
	@s <= DATEDIFF('2022-05-31','2022-05-01')

#查询本周第一天
SELECT DATE_SUB(CURDATE(),INTERVAL WEEKDAY(CURDATE()) DAY) AS TIME

#查询本周的最后一天
SELECT DATE_SUB(CURDATE(),INTERVAL WEEKDAY(CURDATE())-6 DAY) AS TIME

#查询本月的第一天
SELECT DATE_SUB(CURDATE(),INTERVAL DAY(CURDATE())-1 DAY) AS TIME

#查询本月的最后一天
SELECT LAST_DAY(CURDATE()) AS TIME

#当前quarter的第一天：  
select concat(date_format(LAST_DAY(MAKEDATE(EXTRACT(YEAR FROM  CURDATE()),1) + interval QUARTER(CURDATE())*3-3 month),'%Y-%m-'),'01'); 
 
#当前quarter的最后一天：  
select LAST_DAY(MAKEDATE(EXTRACT(YEAR  FROM CURDATE()),1) + interval QUARTER(CURDATE())*3-1 month);

#当年第一天：
SELECT DATE_SUB(CURDATE(),INTERVAL dayofyear(now())-1 DAY);
 
#当年最后一天：
SELECT concat(YEAR(now()),'-12-31'); 

#新增一个星期
SELECT DATE_ADD(now(), INTERVAL 1 week) time

#新增一个月
SELECT DATE_ADD(now(), INTERVAL 1 month) time

#新增一个季度
SELECT DATE_ADD(now(), INTERVAL 1 quarter) time

#新增一年
SELECT DATE_ADD(now(), INTERVAL 1 year) time

#查询本日的数据
SELECT T.* FROM buz_sampling_data T
WHERE TO_DAYS(TIME) = TO_DAYS(NOW())


#查询本周的数据
SELECT T.* FROM buz_sampling_data T
WHERE YEARWEEK(TIME,1) = YEARWEEK(NOW(),1)


#查询本月的数据
SELECT T.* FROM buz_sampling_data T
WHERE MONTH(TIME) = MONTH(NOW())


#查询本年的数据
SELECT T.* FROM buz_sampling_data T
WHERE YEAR(TIME) = YEAR(NOW())