HIVE直接讀入json的函數有兩個：
（1）get_json_object(string json_string, string path)
返回值: string
說明：解析json的字符串json_string,返回path指定的內容。如果輸入的json字符串無效，那么返回NULL。
舉例：
hive> select get_json_object(‘{“store”:{“fruit”:[{"weight":8,"type":"apple"},{"weight":9,"type":"pear"}], “bicycle”:{“price”:19.95,”color”:”red”}}, “email”:”amy@only_for_json_udf_test.net”, “owner”:”amy” } ‘,’$.owner’) from dual;
結果：amy
這個函數每次只能返回一個數據項。
（2）json_tuple(jsonStr, k1, k2, ...)
參數為一組鍵k1，k2……和JSON字符串，返回值的元組。該方法比 get_json_object 高效，因為可以在一次調用中輸入多個鍵
select a.timestamp, b.*
from log a lateral view json_tuple(a.appevent, 'eventid', 'eventname') b as f1, f2;
處理數據樣例：
{"GPS_LAT":39.8965125,"GPS_LONG":116.3493225,"GPS_SPEED":20.9993625,"GPS_STATE":"A","GPS_TIME":"2014-01-02 00:00:16","IMEI":"508597","after_oxygen_sensor":132,"air_condion_state":3,"bdoneNo_after_mileage":0,"bdoneNo_zero_mileage":8044,"db_speed":22,"direction_angle":358.2585,"front_oxygen_sensor":64,"instant_fuel":233,"speed":1210,"torque":33,"total_fuel":0}
處理HIVE語句：
create table 2014jrtest as select json_tuple(line,'GPS_LAT','GPS_LONG','GPS_SPEED','GPS_STATE','GPS_TIME','IMEI','after_oxygen_sensor','air_condion_state','bdoneNo_after_mileage','bdoneNo_zero_mileage','db_speed','direction_angle','front_oxygen_sensor','instant_fuel','speed','torque','total_fuel') from 2014test;
