Скачать или смотреть Solving SQLite's no such column Error in Your Android To-Do List App

Learn how to troubleshoot and resolve common SQLite errors in your Android To-Do List app, particularly focusing on the `no such column` error when querying the database.
---
This video is based on the question https://stackoverflow.com/q/63716354/ asked by the user 'william_' ( https://stackoverflow.com/u/13414648/ ) and on the answer https://stackoverflow.com/a/63717527/ provided by the user 'John Joe' ( https://stackoverflow.com/u/5156075/ ) 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: no such column error on querying sqlite database

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.
---
Troubleshooting no such column Error in SQLite for Your To-Do List App

Creating a simple to-do list app can be a fun and rewarding project, especially when you allow users to store and manage tasks effectively. However, while working with databases such as SQLite, you might encounter issues—one of the most common being the no such column error. This guide will guide you through understanding this error and how to resolve it in the context of your Android app.

The Problem: Understanding the no such column Error

While developing your to-do list app, you encountered the following error when trying to query tasks based on their completion status:

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

This error highlights that SQLite cannot recognize the column in question, resulting in the function failing and causing frustration for developers.

The Solution: Correcting the SQL Query

To resolve this error, it is crucial to understand how to structure your SQL queries correctly. In your case, the issue comes from how the selection parameter is formatted in your query logic.

The Correct Query Structure

Instead of directly including strings in your query, you should use placeholders to avoid SQL syntax errors. Here’s how to fix your SQL query:

Original Code

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

Revised Code

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

Explanation

Placeholders in SQLite

Using ? as a Placeholder: Replace the actual value in the query with a placeholder (?). This prevents SQL syntax errors and safeguards against SQL injection.

Providing the Value: The value for the placeholder is supplied through a separate array, which in this case is new String[]{notComplete}. This ensures that the query compiler can differentiate between the SQL commands and the actual data.

Advantages of Using Placeholders

Improved Security: Reduces the risk of SQL injection attacks.

Clearer Code: Makes your SQL queries easier to read and maintain.

Summary

When working with SQLite in your Android to-do list application, ensuring that your SQL queries are correctly structured is essential for smooth database operations. By implementing the suggestions in this post, you can effectively resolve the no such column error and continue building your app with confidence.

With this knowledge, you should now be equipped to handle similar errors in the future and maintain a seamless user experience in your application. Happy coding!