How to Execute a SELECT Query with Two Columns Using Sqflite in Flutter

Описание: Learn how to use the `OR` operator in Sqflite to select data from multiple columns efficiently in your Flutter applications.
---
This video is based on the question https://stackoverflow.com/q/71915011/ asked by the user 'Carlos Peñaranda' ( https://stackoverflow.com/u/13800717/ ) and on the answer https://stackoverflow.com/a/71915099/ provided by the user 'forpas' ( https://stackoverflow.com/u/10498828/ ) 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: sqflite: How to make a SELECT with two columns inside the same rawQuery

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.
---
Leveraging Sqflite: How to Select Data from Multiple Columns in Flutter

Working with databases in mobile applications can sometimes present unique challenges, especially when it comes to retrieving data from multiple sources. If you're using the Sqflite package in Flutter and you're trying to select information from two columns using an OR operator, fear not! In this guide, we'll walk you through the steps to accomplish this task smoothly.

The Problem Statement

You may have encountered a situation where you want to retrieve entries from a database based on conditions applied to two columns. For instance, you have a table named todos with columns title and categoria. You want to select records where either column matches a specific query string. The desired SQL would look something like this:

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

However, this syntax is incorrect. The challenge here is to effectively use the OR operator to search both columns simultaneously.

The Solution: Using the OR Operator

To perform a query that covers both columns, you can modify your raw query to utilize the OR operator correctly. Here's how you can do this in your Flutter application:

Basic Implementation Example

You can structure your query like this:

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

Alternative Implementation

Another way to execute the same query, especially if you prefer string concatenation in SQL, is:

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

Key Takeaways

Use the OR operator: This is essential for querying multiple columns effectively.

Parameterized Queries: Always use placeholders (?) and parameter arrays to prevent SQL injection attacks and manage data safely.

Understand Your Data: Make sure to tailor the parameters (queryCourse) to fit what you are trying to query.

Conclusion

Retrieving data based on multiple columns is a common requirement in application development, and with the techniques shared above, you’ll be able to execute queries efficiently using Sqflite within Flutter. Always remember to keep your queries secure and well-structured, ensuring that you handle any potential edge cases that might arise with user input.

If you have any other queries regarding Sqflite or Flutter, feel free to reach out or explore more resources available for effective database management in your apps.