问卷问题和答案的合并

得到的question和answer是json格式，字段是map<string,string>，需要将序号和后面的问题或者答案分开，采用lateral view explode的方法，lateral view explode和explode相比，可以select 非炸裂的字段

要注意炸裂后的两个字段不用括号，如果有where，where放在最后面

	select q_key, q_value
	from questionnaire
	lateral view explode(questions) t as q_key, q_value

可以多次使用lateral view explode

  select q_key, q_value, a_key, a_value
  from questionnaire
  lateral view explode(questions) t as q_key, q_value
  lateral view explode(answers) t2 as a_key, a_value
  where q_key=a_key