技術標籤：hive

Lateral View explode使用過程中炸裂行存在空值導致資料丟失的問題

一般使用

select id,con,con_detail
from 
(select 1 as id,'a,b,c' as con
union all select 2 as id,null as con 
union all select 3 as id,'' as con
)t
lateral view explode(split(con,',')) aa as con_detail

結果如下，

發現其中id為2的行不見了，原因是其炸裂的列值為null，解決辦法有兩種，一種是將空值進行非空

select id,con,con_detail
from 
(select 1 as id,'a,b,c' as con
union all select 2 as id,null as con 
union all select 3 as id,'' as con
)t
lateral view outer explode(split(con,',')) aa as con_detail

結果如下，