SELECT
	DATE_FORMAT(add_time, '%Y-%m-%d') as 'add_time',
	COUNT(add_time) as 'reach_intention'
FROM
	table1
where
## where 條件可以根據(jù)自己實(shí)際情況來定
	DATE_FORMAT(add_time, '%Y-%m-%d') > DATE_FORMAT(date_sub(now(), interval 1 month), '%Y-%m-%d')
group by
	DATE_FORMAT(add_time, '%Y-%m-%d')

這是查詢出來的結(jié)果

結(jié)果一

第二條select：

select
	DATE_FORMAT(add_date, '%Y-%m-%d') as 'add_time' ,
	COUNT(add_date)  as 'post_release'
from
	table2
where
## where 條件可以根據(jù)自己實(shí)際情況來定
	DATE_FORMAT(add_date, '%Y-%m-%d') > DATE_FORMAT(date_sub(now(), interval 1 month), '%Y-%m-%d')
group by
	DATE_FORMAT(add_date, '%Y-%m-%d')

第二條select查詢出來的結(jié)果

2.合并查詢結(jié)果

先把兩條select用union all連接起來

SELECT
		DATE_FORMAT(add_time, '%Y-%m-%d') as 'add_time', COUNT(add_time) as 'reach_intention' ,  '' as 'post_release'
	FROM
		table1
	where
		DATE_FORMAT(add_time, '%Y-%m-%d') > DATE_FORMAT(date_sub(now(), interval 30 day), '%Y-%m-%d')
	group by
		DATE_FORMAT(add_time, '%Y-%m-%d')
UNION ALL
	select
		DATE_FORMAT(add_date, '%Y-%m-%d') as 'add_time' , '' as 'reach_intention' ,  COUNT(add_date) as 'post_release'
	from
		table2
	where
		DATE_FORMAT(add_date, '%Y-%m-%d') > DATE_FORMAT(date_sub(now(), interval 30 day), '%Y-%m-%d')
	group by
		DATE_FORMAT(add_date, '%Y-%m-%d')

在外層嵌套一個select

## 括號里面放 用 union all 連接的select 
select * from () test
## 這里要給表起個別名 不然會報 Every derived table must have its own alias 每個派生表都必須有自己的別名

把union all 連接的select 放到括號里面去然后運(yùn)行

select
	*
from
(
	SELECT
		DATE_FORMAT(add_time, '%Y-%m-%d') as 'add_time', COUNT(add_time) as 'reach_intention' ,  '' as 'post_release'
	FROM
		table1
	where
		DATE_FORMAT(add_time, '%Y-%m-%d') > DATE_FORMAT(date_sub(now(), interval 30 day), '%Y-%m-%d')
	group by
		DATE_FORMAT(add_time, '%Y-%m-%d')
UNION ALL
	select
		DATE_FORMAT(add_date, '%Y-%m-%d') as 'add_time' , '' as 'reach_intention' ,  COUNT(add_date) as 'post_release'
	from
		table2
	where
		DATE_FORMAT(add_date, '%Y-%m-%d') > DATE_FORMAT(date_sub(now(), interval 30 day), '%Y-%m-%d')
	group by
		DATE_FORMAT(add_date, '%Y-%m-%d') 
) test

運(yùn)行結(jié)果

把結(jié)果按日期分組排序。

使用 group by 和 order by 關(guān)鍵字

select
	add_time,
	sum(reach_intention) as 'reach_intention' ,
	sum(post_release) as 'post_release'
from
	(
	SELECT
		DATE_FORMAT(add_time, '%Y-%m-%d') as 'add_time', COUNT(add_time) as 'reach_intention' , '' as 'post_release'
	FROM
		table1
	where
		DATE_FORMAT(add_time, '%Y-%m-%d') > DATE_FORMAT(date_sub(now(), interval 30 day), '%Y-%m-%d')
	group by
		DATE_FORMAT(add_time, '%Y-%m-%d')
UNION ALL
	select
		DATE_FORMAT(add_date, '%Y-%m-%d') as 'add_time' , '' as 'reach_intention' , COUNT(add_date) as 'post_release'
	from
		table2
	where
		DATE_FORMAT(add_date, '%Y-%m-%d') > DATE_FORMAT(date_sub(now(), interval 30 day), '%Y-%m-%d')
	group by
		DATE_FORMAT(add_date, '%Y-%m-%d') ) test
group by
	test.add_time
order by
	test.add_time desc

結(jié)果如下