HIVE直接讀入json的函式有兩個：

（1）get_json_object(string json_string, string path)

返回值: string

說明：解析json的字串json_string,返回path指定的內容。如果輸入的json字串無效，那麼返回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”:”
 
[email protected]_for_json_udf_test.net”, “owner”:”amy” } ‘,’$.owner’) from dual;

結果：amy

這個函式每次只能返回一個數據項。

（2）json_tuple(jsonStr, k1, k2, ...)

引數為一組鍵k1，k2……和JSON字串，返回值的元組。該方法比 get_json_object 高效，因為可以在一次呼叫中輸入多個鍵

select a.timestamp, b.*
from log a lateral view json_tuple(a.appevent, 'eventid', 'eventname') b as f1, f2;
 

處理資料樣例：

{
	"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;

作者：石曉文的學習日記 連結：https://www.jianshu.com/p/8a868d2ac307 來源：簡書 簡書著作權歸作者所有，任何形式的轉載都請聯絡作者獲得授權並註明出處。