问题：
将MongoDB数据导入Hive，按照https://blog.csdn.net/thriving_fcl/article/details/51471248文章，在hive建外部表与mongodb做映射后，执行后出现
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. com/mongodb/util/JSON
建表语句如下：
CREATE EXTERNAL TABLE mongotohive
(
id string,
userid string,
age bigint,
status string
)
STORED BY 'com.mongodb.hadoop.hive.MongoStorageHandler'
WITH SERDEPROPERTIES('mongo.columns.mapping'='{"id":"_id","userid":"user_id","age":"age","status":"status"}')
TBLPROPERTIES('mongo.uri'='mongodb://localhost:27017/mydb.users');
mongodb 数据如下：
db.users.find()
{ "_id" : ObjectId("5b456e33a93daf7ae53e6419"), "user_id" : "abc123", "age" : 58, "status" : "D" }
{ "_id" : ObjectId("5b45705ca93daf7ae53e8b2a"), "user_id" : "bcd001", "age" : 45, "status" : "C" }
解决方案：
将mongo-hadoop-core-2.0.0.jar、mongo-hadoop-hive-2.0.0.jar、mongo-java-driver-3.7.1.jar三个jar包放到hive的lib文件夹下后，再次运行成功。如下：
hive> CREATE EXTERNAL TABLE mongotohive
> (
> id string,
> userid string,
> age bigint,
> status string
> )
> STORED BY 'com.mongodb.hadoop.hive.MongoStorageHandler'
> WITH SERDEPROPERTIES('mongo.columns.mapping'='{"id":"_id","userid":"user_id","age":"age","status":"status"}')
> TBLPROPERTIES('mongo.uri'='mongodb://localhost:27017/mydb.users');
OK
Time taken: 1.431 seconds
hive> select * from mongotohive;
OK
5b456e33a93daf7ae53e6419 abc123 58 D
5b45705ca93daf7ae53e8b2a bcd001 45 C
Time taken: 0.601 seconds, Fetched: 2 row(s)
hive>
