How to export data from cassandra to Json file using Python or other language?

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I want to export data from Cassandra to Json file, because Pentaho didn't support my version of Cassandra 3.10

You can simply add json after select to get your results in json format:

cqlsh:cycling> select json name, checkin_id, timestamp from checkin;
 [json]
------------------------------------------------------------------------------------------------------------------
 {"name": "BRAND", "checkin_id": "50554d6e-29bb-11e5-b345-feff8194dc9f", "timestamp": "2016-08-28 21:45:10.406Z"}
  {"name": "VOSS", "checkin_id": "50554d6e-29bb-11e5-b345-feff819cdc9f", "timestamp": "2016-08-28 21:44:04.113Z"}
(2 rows)

Taken from https://docs.datastax.com/en/cql/3.3/cql/cql_using/useQueryJSON.html

How to export data from cassandra to Json file using Python or other , rate: 30 rows/s 6 rows exported to 1 files in 0.213 seconds. Now, we are going to delete data from table 'Data' to import again from CSV file which� When exporting data (COPY TO), the default is to output all columns from the Cassandra table metadata, in the order defined. If you only want to export a particular set of columns, you can specify the column names in parentheses after the table name. The destination for the output CSV is specified either by a file path or by the keyword "STDOUT".

DataStax now provides the tool called DSBulk that works with both DSE & Cassandra, and it's heavily optimized to load and unload data to/from DSE/Cassandra. It supports output as JSON format as well, like this:

dsbulk unload -k keyspace -t table -url out_dir -c json

More examples of unloading data, could be found in this blog post, that is part of the series of blog posts on DSBulk. For example, you can specify which columns of the table to offload, etc.

Export and Import data in Cassandra, How to export data from cassandra to Json file using Python or other language? I want to export data from Cassandra to Json file, because Pentaho didn't� To provide you some context, here is a template that you may use in Python to export pandas DataFrame to JSON: df.to_json(r'Path to store the exported JSON file\File Name.json') Next, you’ll see the steps to apply this template in practice. Steps to Export Pandas DataFrame to JSON Step 1: Gather the Data

I had the same need to export cassandra tables as JSON and built a command line tool for it:

Retrieval using JSON, Using the SELECT command to return JSON data. Introduction to Cassandra Query Language � CQL data modeling � Using CQL � CQL reference � DataStax LunaEnterprise Support for Apache Cassandra — Start a Free 30-Day For more information, see What's New in Cassandra 2.2: JSON Support. This tutorial shows how easy it is to use the Python programming language to work with JSON data. Before I begin the topic, let's define briefly what we mean by JSON. Let's see how JSON's main website defines it: JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write.

You can use bash redirction to get json file.

cqlsh -e "select JSON * from ${keyspace}.${table}" | awk 'NR>3 {print $0}' | head -n -2 > table.json

COPY, Introduction to Cassandra Query Language � CQL data modeling � Using CQL shell commands that import and export CSV (comma-separated values or delimited text files). COPY TO exports data from a table into a CSV file. a list of one or more comma-separated file names or python glob expressions. I am trying to find out ways on how you can efficient load data into Cassandra in Python whether it be a 1000 or a million records. I am a beginner to both Cassandra and Python and did read using a batch statement might be a option, but it sounds like that would still load records a row at a time.

Apache Cassandra - Tutorial 12 - CQL, We can import and export data from Apache Cassandra database tables to basic csv files Duration: 8:45 Posted: Feb 22, 2019 If you'd like to learn more about using CSV files in Python in more detail, you can read more here: Reading and Writing CSV Files in Python. Saving a JSON File. JSON is another popular format for storing data, and just like with CSVs, Python has made it dead simple to write your dictionary data into JSON files: import json my_details = { 'name

Importing a json file into Cassandra - json - html, Come up with some kind of schema for your JSON data and map it to a CQL table We can achieve this in Python and other programming languages and have� Writing a JSON File. The json module also allows us to write JSON data into a JSON file. JSON files are saved with the .json extension. Let's see how we can do that below. In order to achieve this, we use Python's open() function with w as the parameter to signify that we want to write the file.

Using JSON with Cassandra – BMC Blogs, Cassandra supports JSON, and in this expert guide , complete with code, we'll show you how to use JSON to write to e-book: Simplifying Big Data with Streamlined Workflows Since the sales items are a list we can add more than one. Copy If you want to convert it to a JSON string then use toJson(). When you only need to use JSON for a single column, the new toJson() and fromJson() functions can be used. These behave the same as INSERT JSON and SELECT JSON, but are limited to a single value or column. fromJson() The fromJson() function converts a single JSON-encoded string to a normal Cassandra value. For example, this can be used when

Comments
  • There is jdbc driver for Cassandra, so Pentaho could treat Cassandra as typical SQL database. We've used Pentaho+Cassandra in one of our projects though I'm not sure about Cassandra's version.
  • But I want json file no just json format, how could I save this json?