Hive学习-数据查询语句
1.DQL查询语法
1)查询语法
hive> SELECT [ALL | DISTINCT] SELECT_expr, SELECT_expr, ......(st.info, '$.name') AS name,
get_json_object(st.info, '$.age') AS age,
get_json_object(sc.scores,...,
AVG(CAST(get_json_object(sc.scores, '$.English') AS INT)) AS avg_english,
AVG(CAST(get_json_object...,
AVG(CAST(get_json_object(sc.scores, '$.Physics') AS INT)) AS avg_physics,
AVG(CAST(get_json_object...k1=v1&k2=v2#Ref1', 'QUERY', 'k1');v1
get_json_object(string json_string, string path) 解析json的字符串json_string