Fixing Duplicate Results in JSON Output from PyMySQL Queries

Discover why your JSON built with PyMySQL is returning duplicate results and learn how to fix it efficiently.
---

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: Why is my json built using PyMySQL returning with duplicate results?

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding Why Your JSON Built Using PyMySQL Is Returning Duplicate Results

Have you ever encountered a situation where the JSON output from your database query contains duplicate results? This can be frustrating, especially when you expect a certain number of distinct records. In this guide, we will explore the common causes behind this issue and walk you through a solution that simplifies your code and eliminates the problem of duplicates.

The Problem: Unexpected Duplicates in JSON Output

In your case, you're using PyMySQL to execute a SELECT statement on a MySQL database, and then converting the results into a JSON format to send to your mobile application.

While testing, you've noticed an inconsistency in your output: instead of returning the expected 10 rows, your JSON contains 104 duplicate rows. It’s crucial to understand the underlying issue to effectively solve it.

Analyzing Your Code

Here’s a snippet of your code that illustrates the problem:

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

What Went Wrong?

The Solution: Properly Structuring Your Code

To resolve this issue, you need to adjust the indentation so that you only append the row dictionary once per iteration of the outer loop. Here’s how you can revise your code:

Updated Code

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

Explanation of Changes

Clarity and Efficiency: This change not only fixes the duplication issue but also makes the code clearer and easier to maintain.

Conclusion

If you've encountered a situation where your JSON output is filled with duplicate results from your MySQL queries, the problem often lies in how you structure your loops. By ensuring that each row is processed and appended correctly, you can avoid such pitfalls and enhance the functionality of your database interactions. Always remember to review your loop structures—small indentation errors can lead to significant issues like unexpected duplicates.

With this adjustment to your code, you should now see the correct number of rows in your JSON output. Happy coding!