Hive casting of MongoDb Date - mongodb

Question

I'm linking Hive to a MongoDb collection that has a date. The MongoDB collection's structure looks like this:
{
"name" : "Using Hive",
"validFrom" : ISODate("2014-11-04T00:00:00.000Z"),
"validTo" : ISODate("2016-01-30T00:00:00.000Z"),
"_id" : ObjectId("54da1c02ead8571c292901d3")
}
I'm adding it to Hive as follows:
CREATE TABLE certificate
(
name STRING,
validFrom TIMESTAMP,
validTo TIMESTAMP,
id STRING
)
STORED BY 'com.mongodb.hadoop.hive.MongoStorageHandler'
WITH SERDEPROPERTIES('mongo.columns.mapping'='{"id":"_id"}')
TBLPROPERTIES('mongo.uri'='mongodb://localhost:27017/test.certificate');
When I get do a select the dates are null:
hive> select * from certificate;
OK
Using Hive NULL NULL 54da1c02ead8571c292901d3
MongoDb NULL NULL 54da1c02ead8571c292901d4
Hadoop NULL NULL 54da1c02ead8571c292901d5
I know Hive supports date casting, is that something I can do with the CREATE statement to ensure the dates are correctly cast? I'll be using queries with "where valid from date's less than today and valid to date's more than today" and such, so having those columns as dates and not strings is vital.
Thanks =D

Answer 1

Specify the mappings for columns validFrom and validTo. By default hive converts column names to lowercase. Please check if following works.
CREATE TABLE certificate
(
name STRING,
validfrom TIMESTAMP,
validto TIMESTAMP,
id STRING
)
STORED BY 'com.mongodb.hadoop.hive.MongoStorageHandler'
WITH SERDEPROPERTIES('mongo.columns.mapping'='{"id":"_id","validfrom":"validFrom","validto":"validTo"}')
TBLPROPERTIES('mongo.uri'='mongodb://localhost:27017/test.certificate');