How to Achieve a Group By Functionality in jq for JSON Objects

Learn how to effectively use jq to `group` JSON data by keys in a structured format with this helpful guide.
---
This video is based on the question https://stackoverflow.com/q/69968773/ asked by the user 'EmaX' ( https://stackoverflow.com/u/4187881/ ) and on the answer https://stackoverflow.com/a/69969381/ provided by the user 'peak' ( https://stackoverflow.com/u/997358/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to Group By within Object in jq

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Achieve a Group By Functionality in jq for JSON Objects

When working with JSON data, you may find yourself in a situation where you need to restructure the data for better clarity and usability. One common challenge is grouping data by a certain key within nested objects. In this guide, we'll address this exact issue and provide a clear solution using jq, a lightweight and flexible command-line JSON processor.

Understanding the Problem

Let’s start by examining a sample JSON object that illustrates the problem you may face:

[[See Video to Reveal this Text or Code Snippet]]

In the above example, you can see that for each unique identifier (id_1, id_2), the data related to different days (day_1, day_2) is separated. The desired output is to group these days under their respective IDs as shown below:

[[See Video to Reveal this Text or Code Snippet]]

The jq Solution

To achieve this grouping in bash using jq, you can utilize the command's powerful streaming capabilities. Follow the steps outlined below to implement this solution.

Step-by-Step Instructions

Prepare Your Input: Save your original JSON object to a file named input.json.

Use jq with the Stream Option: Run the following jq command in your bash terminal:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Command

-n --stream: This tells jq to read data in streaming mode, allowing the processing of the input in a way that handles large files efficiently.

def stream: This defines a custom function named stream that will be used to process the data.

foreach: This iterates over each key-value pair in the JSON data.

setpath: This function is utilized to store values at specific paths dynamically, allowing the restructuring of the JSON object.

Considerations

Ensure that the JSON structure in input.json is correctly formatted without duplicate keys for the jq command to work correctly.

You might explore modifying this jq script for other similar structured JSON objects.

Conclusion

Manipulating JSON data with jq can be incredibly powerful, especially for organizing your data in a clean and structured way. By applying the method described above, you can efficiently group data by keys within an object. The ability to restructure JSON can significantly enhance both data analysis and visualization efforts.

Feel free to reach out if you have any questions or need further assistance with jq commands or JSON data manipulation!

Видео How to Achieve a Group By Functionality in jq for JSON Objects канала vlogize