Tips

Can we create Hive table on JSON file?

Author 0 comment

Can we create Hive table on JSON file?

To make a Hive table out of a JSON file you need to write the CREATE TABLE statement based on HiveQL DDL standards specifically for your JSON structure. Using HiveQL to analyse JSON files require either org.

Can JSON be nested?

Objects can be nested inside other objects. Each nested object must have a unique access path. The same field name can occur in nested objects in the same document.

How do I access nested JSON data?

Accessing nested json objects is just like accessing nested arrays. Nested objects are the objects that are inside an another object. In the following example ‘vehicles’ is a object which is inside a main object called ‘person’. Using dot notation the nested objects’ property(car) is accessed.

How do I query JSON data in Hive?

READ:   What does it mean for domain names to be hierarchical?

Hive provides three different mechanisms to run queries on JSON documents, or you can write your own:

  1. Use the get_json_object user-defined function (UDF).
  2. Use the json_tuple UDF.
  3. Use the custom Serializer/Deserializer (SerDe).
  4. Write your own UDF by using Python or other languages.

What is JSON SerDe in Hive?

The Hive JSON SerDe is commonly used to process JSON data like events. These events are represented as blocks of JSON-encoded text separated by a new line. The Hive JSON SerDe does not allow duplicate keys in map or struct key names.

Can JSON have nested array?

A JSON document can have JSON objects nested inside other JSON objects. JSON objects are key-value pairs and there are different methods you can use to access JSON objects from a nested JSON document. One method is to use recursion just like you access data from a nested array or tree data structure.

What is JSON nested?

Nested JSON is simply a JSON file with a fairly big portion of its values being other JSON objects. Compared with Simple JSON, Nested JSON provides higher clarity in that it decouples objects into different layers, making it easier to maintain. Using Phrase, keys will be stored by separating levels with a dot.

READ:   What is Panchakarma treatment in Kerala?

What is nested JSON?

How can I access and process nested objects arrays or JSON?

A nested data structure is an array or object which refers to other arrays or objects, i.e. its values are arrays or objects. Such structures can be accessed by consecutively applying dot or bracket notation.

How will you create a table in Hive for a JSON input file?

json-serde jar is located at /data/serde directory in hdfs, before creating the table add the serde jar in hive with add jar followed by jar path command now you can create the table using the syntax displayed on the screen please note the row format unlike previous examples fields are not terminated by tab or comma.

How do I load a JSON file into a hive table?

Steps:

  1. Load JSON file from your home folder in HDFS to Hive.
  2. Login to the web console.
  3. Copy /data/sample_json from HDFS to your home folder in HDFS. $
  4. Check the content of the sample_json directory.
  5. It contains the file user_country.
  6. Launch Hive by typing hive in the web console.
  7. Use your database.
READ:   What is the benefits of Prithvi Mudra?

How do I create a hive table from a JSON file?

To make a Hive table out of a JSON file you need to write the CREATE TABLE statement based on HiveQL DDL standards specifically for your JSON structure. It can be very complicated if you are using a nested JSON file so I recommend you to use this quick and easy generator: https://hivetablegenerator.com/

How to deserialize JSON data in hcatalog-core?

Hive 0.12 and later in hcatalog-core has JsonSerDe which will serialize and deserialize your JSON data. So, all you need to do is create an external table like the following example: The corresponsing json data file should look like the following example:

Is jsonserde a valid JSON?

The above Json is a valid Json. I want to create a hive table on top of data of above form using JsonSerde. jsonhivecreate-tablehive-serdehiveddl

What is JSON serde in hive?

This is the default JSON SerDe from Apache. This is commonly used to process JSON data like events. These events are represented as blocks of JSON-encoded text separated by a new line. The Hive JSON SerDe does not allow duplicate keys in map or struct key names.