hive---内置函数(2)表生成函数

表生成函数：可以理解为一个函数可以生成一个表

行转列函数：

explode(字段名--hive中集合类型中的array，map)----炸开字段内容

distinct去重

select distinct sub from (select explode(subjects) as sub from t_stu_subject) temp;

表生成函数：lateral view

目标表

select id,name,tmp.sub

from t_stu_subject later view wxplode(subjects) tmp as sub;