使用HiveSQL实现开始到结束日期之间的所有日期

Hivesql实现日期间所有日期
或 返回所有日期
如给定起止日期返回中间所有日期

（posexplode比 explode多返回一个postion，利用postion进行下一步的关联操作）

给定表 user 如下：

uid	start_date	end_date
1	2020-01-01	2020-01-05

查询1：

set hive.exec.mode.local.auto=true; --开启本地模式
set hive.cli.print.header=true; --打印表.列名

select 
    tmp.*, 
    t.*, 
    date_add(start_date, pos) as mid_date
from(
    select '1' as uid,
    '2020-01-01' as start_date, 
    '2020-01-05' as end_date 
)tmp
lateral view posexplode( split( space( datediff( end_date, start_date ) ), '' ) ) t as pos, val
;

查询1的结果：

tmp.uid	tmp.start_date	tmp.end_date	t.pos	t.val	mid_date
1	2020-01-01	2020-01-05	0	 	2020-01-01
1	2020-01-01	2020-01-05	1	 	2020-01-02
1	2020-01-01	2020-01-05	2	 	2020-01-03
1	2020-01-01	2020-01-05	3	 	2020-01-04
1	2020-01-01	2020-01-05	4		2020-01-05
Time taken: 0.086 seconds, Fetched: 5 row(s)

– 查询2：

select 
    tmp.*, 
    t.*, 
    date_add(start_date, pos) as mid_date
from(
    select '1' as uid,
        '2020-01-01' as start_date, 
        '2020-01-05' as end_date 

    union all
    select '1' as uid,
        '2020-01-01' as start_date, 
        '2020-01-25' as end_date 
)tmp
lateral view posexplode( split( repeat( 'a', datediff( '2020-01-05', '2020-01-01' )), '' ) ) t as pos, val
;

查询2的结果：

tmp.uid	tmp.start_date	tmp.end_date	t.pos	t.val	mid_date
1	2020-01-01	2020-01-05	0	a	2020-01-01
1	2020-01-01	2020-01-05	1	a	2020-01-02
1	2020-01-01	2020-01-05	2	a	2020-01-03
1	2020-01-01	2020-01-05	3	a	2020-01-04
1	2020-01-01	2020-01-05	4		2020-01-05
1	2020-01-01	2020-01-25	0	a	2020-01-01
1	2020-01-01	2020-01-25	1	a	2020-01-02
1	2020-01-01	2020-01-25	2	a	2020-01-03
1	2020-01-01	2020-01-25	3	a	2020-01-04
1	2020-01-01	2020-01-25	4		2020-01-05
Time taken: 1.335 seconds, Fetched: 10 row(s)