Скачать или смотреть How to Flatten XML using SQL Server without Duplicate Values

Learn how to effectively flatten XML data using SQL Server with XQuery methods instead of OPENXML, avoiding duplicate values in your output.
---
This video is based on the question https://stackoverflow.com/q/72665947/ asked by the user 'B Ward' ( https://stackoverflow.com/u/6750700/ ) and on the answer https://stackoverflow.com/a/72666015/ provided by the user 'AlwaysLearning' ( https://stackoverflow.com/u/390122/ ) 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: Trying to flatten XML using SQL Server XMLOPEN however values are repeating in nested rows

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.
---
Flattening XML in SQL Server: A Deep Dive into SQL Queries

When working with XML data in SQL Server, one common challenge developers face is flattening that XML into a relational format. This task sometimes results in repeated values in nested rows, leading to confusion and inaccuracies in data representation. Let's explore a practical scenario where this problem arises and how to efficiently solve it.

Understanding the Problem

In this example, we want to flatten the following XML structure:

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

When using the OPENXML method, the output shows duplicate values for certain columns, particularly in the Direct column. Here’s a closer look at the data we want to derive from this XML:

NameCodeNameSequencesSequenceDirectLEESA5YBAS12,3012PUNED/BODAS/OSINA/IGDEB/LEESALEESA5YBAS12,3030RUGMU/IGDEB/LEESAHowever, using the initial SQL Server query led to an unexpected result where the last value of the Direct column was repeated. To avoid this issue, we need a better approach.

The Solution: Utilizing XQuery Methods

Instead of OPENXML, we will utilize XQuery methods from SQL Server which are more efficient and prevent the repetition of values. Here’s how to do it properly:

Step-by-Step Implementation

Define the XML Variable: Start by storing your XML data in a variable.

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

Query the XML Data: Use nodes() and cross apply to extract the needed values without repetitions.

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

Resulting Output

By running the above query, you will achieve the desired output without repeated values:

NameCodeNameSequencesSequenceDirectLEESA5YBAS12,3012PUNED/BODAS/OSINA/IGDEB/LEESALEESA5YBAS12,3030RUGMU/IGDEB/LEESAConclusion

Handling XML data effectively in SQL Server can be tricky, especially when it comes to ensuring that your output is clean and logical. By transitioning from OPENXML to XQuery methods, we eliminate issues with repeated values and streamline the extraction process. This not only improves the reliability of your data representation but also enhances your overall workflow in SQL Server.

For any SQL Server developer, mastering these techniques will significantly improve your ability to work with XML data seamlessly.