sql获取连续日期

### MYSQL获取一整月的日期列
## 第一种
SELECT
	date_list,
	CASE
		DAYOFWEEK( date_list ) 
		WHEN 1 THEN
		'星期日' 
		WHEN 2 THEN
		'星期一' 
		WHEN 3 THEN
		'星期二' 
		WHEN 4 THEN
		'星期三' 
		WHEN 5 THEN
		'星期四' 
		WHEN 6 THEN
		'星期五' 
		WHEN 7 THEN
		'星期六' 
	END week_name 
FROM
	(
	SELECT
		date_add( curdate( ), INTERVAL t.help_topic_id DAY ) AS date_list 
	FROM
		mysql.help_topic t 
	WHERE
	t.help_topic_id < DAY ( last_day( curdate( ) ) ) 
	) t1;
	
## 第二种
SELECT DATE_FORMAT(DATE_SUB(LAST_DAY(NOW()), INTERVAL xc-1 DAY), '%Y-%m-%d') as date
FROM 
	( 
		SELECT @xi:=@xi+1 as xc from 
		(SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5) xc1, 
		(SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6) xc2,  
		(SELECT @xi:=0) xc0 
	) xcxc;