Скачать или смотреть How to Delete Items from SQLiteOpenHelper in Android?

Learn the simple methods to delete items from your SQLiteOpenHelper database when using RecyclerView in your Android app.
---
This video is based on the question https://stackoverflow.com/q/65384602/ asked by the user 'TOGIY SOFTWARE' ( https://stackoverflow.com/u/14861610/ ) and on the answer https://stackoverflow.com/a/65387893/ provided by the user 'Nadim Ansari' ( https://stackoverflow.com/u/11760447/ ) 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: How Can I delete item on my SQliteOpenhelper

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.
---
How to Delete Items from SQLiteOpenHelper in Android?

When developing Android applications, managing data effectively is crucial to providing a smooth user experience. If you're using SQLiteOpenHelper to handle your database and RecyclerView to display your data, you might wonder how to delete items not only from the UI but also from the database. In this guide, we’ll guide you through the process of deleting items from your SQLite database when using a RecyclerView.

The Problem

With your existing setup, you've successfully implemented adding and displaying items in a RecyclerView using SQLite for data storage. However, you are facing challenges in ensuring that when an item is deleted from the RecyclerView, it also gets removed from the SQLite database. This disconnect can lead to inconsistencies between the UI and the underlying data.

Understanding SQLiteOpenHelper

SQLiteOpenHelper is a helper class that manages database creation and version management. It's essential for managing your database structure and ensuring smooth data manipulation operations. Below, we will outline how to effectively implement the deletion of entries from the database.

The Solution

To solve the problem of deleting items from your SQLiteOpenHelper database, follow these steps:

Step 1: Add a Delete Method in Your Database Helper Class

You need to implement a method that specifies how to perform the delete operation on your SQLite table. Here's the code snippet to include in your DatabaseHelper:

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

Explanation:

SQLiteDatabase: This is the use of writable database access to modify it.

The query executed via execSQL() specifies that a row should be deleted where the specified ID matches.

Step 2: Call the Delete Method from Your Activity

Once the delete method is in place, you'll need to call this method when an item is deleted from your RecyclerView. This can often be tied to a swipe gesture using ItemTouchHelper.

Here’s how you can integrate it into your todoactivity.java:

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

Step 3: Ensure Proper ID Management

You’ll need to ensure that the IDs used in deleteItem(int iDxxx) match correctly with those stored in your RecyclerView. This will often require storing the ID as part of your list items or retrieving it in a way that allows for accurate deletion calls.

Conclusion

By implementing these steps, you can effectively synchronize your RecyclerView with your SQLite database. Now when you swipe to delete an item, it will be removed from both the RecyclerView display and the database, ensuring data integrity.

Final Thoughts

Managing data in Android applications requires careful attention, especially when it comes to adding and deleting entries. Using the SQLite database in conjunction with RecyclerView can create a powerful setup, and knowing how to manipulate this data is crucial for any Android developer. Happy coding!