hive-行转列列转行

一、

ids	type
1	A
1	C
1	E
2	B
2	D
2	F

 

ids	A	B	C	D	E	F
1	1	0	1	0	1	0
2	0	1	0	1	0	1

将第一个表格的数据变成第二种

两种方式：1. 

 select ids, 
 count(if(type='A',1,null))A,
 count(if(type='B',1,null))B,
 count(if(type='C',1,null))C,
 count(if(type='D',1,null))D,
 count(if(type='E',1,null))E,
 count(if(type='F',1,null))F from lp.study group by ids;

2.

 select ids,sum(if(type='A',1,0))A,
 sum(if(type='B',1,0))B,
 sum(if(type='C',1,0))C,
 sum(if(type='D',1,0))D,
 sum(if(type='E',1,0))E,
 sum(if(type='F',1,0))F from lp.study group by ids;

二.行转列 使用 collect_set

ids	type
1	A
1	C
1	E
2	B
2	D
2	F

ids	type
1	A,C,E
2	B,D,F

将第一个表格转为第二个表格

select ids,concat_ws(",",collect_set(type)) types  from lp.study group by ids;

三.列传行 使用 lateral view explode

ids	type
1	A,C,E
2	B,D,F

ids	type
1	A
1	C
1	E
2	B
2	D
2	F

将第一个表格转为第二个表格

select ids,type from 
 (select ids,concat_ws(",",collect_set(type)) types  from lp.study group by ids) a lateral view explode(split(types,",")) col as type ;