将每一行数据存储为string,属性名line
get_json_object()
select get_json_object(line,'$.movie') as movie, get_json_object(line,'$.rate') as rate, get_json_object(line,'$.timeStamp') as time, get_json_object(line,'$.uid') as uid from rate_json;
json_tuple()
select b.movie,b.rate,b.time,b.uid from rate_json lateral view json_tuple(line,'movie','rate','timeStamp','uid') b as movie,rate,time,uid;



