Скачать или смотреть How to Get Yesterday's Date in Apache NiFi Using Expressions

Learn how to easily obtain `yesterday's timestamp` in Apache NiFi with a simple expression. Follow our step-by-step guide to format it as you need!
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This video is based on the question https://stackoverflow.com/q/66535427/ asked by the user 'Arun Sai Mustyala' ( https://stackoverflow.com/u/11243901/ ) and on the answer https://stackoverflow.com/a/66535603/ provided by the user 'daggett' ( https://stackoverflow.com/u/1276664/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Mastering Date Management in Apache NiFi: Get Yesterday's Date

Managing dates accurately is crucial in data processing. Whether you are scheduling tasks or generating reports, knowing how to manipulate dates can save you time and hassle. In this guide, we’ll tackle a common challenge: how to get yesterday's timestamp in Apache NiFi's expression language. If you've already figured out how to get the current timestamp using now(), you are halfway there! Let's explore how to extend that knowledge to retrieve dates from the past.

The Problem: Obtaining Yesterday's Date

You might be in a scenario where you need to generate timestamps from previous days for logging, reporting, or data processing purposes. For instance, if you want to create a timestamp for yesterday at 23:59:00 like so: "superDate":"2021-03-07 23:59:00", you'll need a way to adjust the current timestamp back by one day.

Why Use now() Instead of Static Dates?

Using dynamic timestamps such as now() is more efficient than hardcoding dates. This approach ensures that your application always refers to the correct time based on the current date, making your workflows flexible and reliable.

The Solution: Using NiFi Expressions

To calculate yesterday's date in Apache NiFi, you can use a specific expression that retrieves the current timestamp and subtracts the necessary amount of time. Below is the expression you'll need:

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

Breaking Down the Expression

Let’s take a closer look at each part of this expression:

${now()}: This function retrieves the current date and time.

:toNumber(): Converts the current timestamp to a numeric value (milliseconds since epoch).

:minus(86400000): This function subtracts 86,400,000 milliseconds, which is equivalent to 24 hours or one day. This effectively gives you the timestamp for yesterday at the same hour.

:format('yyyy-MM-dd HH:mm:ss'): Finally, this formats the result into a human-readable string with the specified date and time layout.

Example Usage

Using the given expression in your NiFi processor will yield results like the following:

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

This ensures that you can easily manage datasets requiring timestamps from yesterday.

Conclusion

Getting yesterday's timestamp in Apache NiFi can be done swiftly using a single expression. By leveraging the powerful capabilities of NiFi's expression language, you gain precise control over date and time management, enhancing your data workflow efficiency. Now, with this newfound knowledge, you're equipped to tackle date-related challenges in your data processing tasks confidently.

If you have any further questions, feel free to reach out or comment below. Happy NiFi-ing!