java - 通过使用配置单元查询是否可以将表数据转换为复杂类型的list ？

Question

这是表格的详细信息

Id    Data  
a     {"col1":"11.0","col2":30.0}  
a     {"col1":"12.0","col2":10.0}  
b     {"col1":"11.0","col2":20.0}  
b     {"col1":"12.0","col2":25.0}  
b     {"col1":"15.0","col2":25.0}  
c     {"col1":"12.0","col2":15.0}  
c     {"col1":"13.0","col2":16.0}  

预期输出-按ID分组的数据结构列表。

ID  Data  
a   list[ {"col1":"11.0","col2":30.0},{"col1":"12.0","col2":10.0}]  
b   list[ {"col1":"11.0","col2":20.0},{"col1":"12.0","col2":25.0},{"col1":"15.0","col2":25.0}]  
c   list[ {"col1":"12.0","col2":15.0},{"col1":"13.0","col2":16.0}] 

HIVE支持的功能是否可能，还是需要编写任何用户定义的功能。

Answer 1

简短的答案是肯定的，对此有以前的答案，请参见此处

How to get array/bag of elements from Hive group by operator?

但总而言之，如果您只有唯一的元素，则使用collect_set，否则使用collect_list(仅适用于hive 0.13+)，除了它是标准的按查询分组。