hive group by 和 select set

void function(int *a){
*a = 100;
}
int main(){
int x=200;
int *b = &x;
function(b);
return(0);
} 
void function(int &a){
a = 100;
}
int main(){
int x = 200;
function(x);
return(0);
}




hive group by  要和 collect_set 联合使用
select 旧列名 as 新列名 from 旧表 as 新表




返回无重复记录


select max(ubi.id), ubi.name, concat_ws(',', collect_set(ua.address)) as address 






from


 user_basic_info ubi join
ser_address ua 
on
ubi.name=ua.name 
group by ubi.name;  




user_basic_info:




id name
1 a
2 b
3 c
4 d




user_address;
name address
a add1
a add2
b add3
c add4
d add5