Скачать или смотреть How to Use REGEXP_REPLACE in Oracle for Fixed-Length String Formatting

A comprehensive guide on how to use Oracle's `REGEXP_REPLACE` to format strings into fixed lengths for better data presentation.
---
This video is based on the question https://stackoverflow.com/q/65010934/ asked by the user 'Samuel' ( https://stackoverflow.com/u/14567293/ ) and on the answer https://stackoverflow.com/a/65011118/ provided by the user 'MonkeyZeus' ( https://stackoverflow.com/u/2191572/ ) 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: Oracle - use regular expression to format capturing groups

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

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Formatting Strings with Regular Expressions in Oracle

In today’s digital age, data formatting often presents specific challenges—especially when dealing with strings that have multiple components. One common situation is when you have a series of values separated by commas and you want these values presented uniformly with a fixed length.

The Challenge

Imagine you have various inputs containing three groups of strings, separated by commas. The task is to ensure that each of those capturing groups is displayed with a fixed width of ten characters, padded with underscores (_) if they are shorter. The requirement becomes even more specific when dealing with strings of different lengths, as is often the case.

Here's an example input:

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

The desired output should look like this:

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

This discrepancy can lead to unaligned data that is visually unappealing and harder to analyze. Let's explore how to achieve this formatting using Oracle's REGEXP_REPLACE.

The Solution

We can utilize Oracle's REGEXP_REPLACE function, along with multiple replacements and concatenation to solve this problem effectively. Below, I’ll walk you through the steps of writing the SQL query to achieve the desired fixed-length output.

Step-by-Step Instructions

Understanding the REGEXP_REPLACE Function:

This function is designed to search a string for a regular expression pattern and replace it with a specified replacement.

Write the SQL Query:
Here is the SQL query you can use:

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

Explanation of Each Replacement:

The first replacement REGEXP_REPLACE('085,10,1234567', ',.*$', '') removes everything from the first comma to the end, extracting the first value.

The second replacement REGEXP_REPLACE('085,10,1234567', '^[^,]+ ,|,[^,]+ $', '') isolates the second value by removing the first and last elements of the string.

The third replacement REGEXP_REPLACE('085,10,1234567', '^.*,', '') captures the last component, effectively extracting the last number after the last comma.

Results:
When you replace '085,10,1234567' with your actual input string and run the query, it will produce the desired output formatted as:

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

Conclusion

By applying the Oracle REGEXP_REPLACE function alongside logical string manipulations, you can streamline the process of formatting strings to fixed lengths visually. This method ensures that all captured data remains organized and easily readable.

Remember, adapting this query will allow you to handle various string inputs effectively while maintaining a clean, structured output. Whether you’re prepping data for reports, dashboards, or simply improving readability for analytics, mastering these formatting techniques will significantly enhance your data management skills.

Ready to give it a try? Happy querying with Oracle!