How to Recover Deleted Records in SQLite Database? Quickly

Summary: If you’ve accidentally deleted records from SQLite, then read this blog to know the ways to restore the deleted records in SQLite. It constitutes using the hex editor and WAL file to get the job done. It also mentions a professional utility that can easily and quickly recover deleted records from SQLite database files.

Table of Contents:

• How Deletion Works in SQLite
• Methods to Recover Deleted Records in SQLite
• Method 1 – Use SQLite’s Write-Ahead Logging (WAL) File
• Method 2 – Use SQLite Deleted Records Recovery Tools
• Steps to Recover Deleted Records in SQLite using SysTools Software
• Method 3 – Use Data Carving Techniques Manually
• Method 4 – Use Backup Files
• FAQs
• Conclusion

SQLite has been one of the favorite choices for lightweight, file-based data management, from mobile to desktop applications. Recovery of deleted records from SQLite is a difficult proposition despite its simplicity in design due to how SQLite manages storage and deletes the data. It lacks an “undo” facility or data recovery like the general RDBMS systems. Therefore, recovering a deleted record becomes complex and sometimes requires very specialized tools and techniques.

This article is aimed at describing effective ways to restore deleted records in SQLite databases. It will also disclose some best practices concerning the preservation and handling of data.

How Deletion Works in SQLite

Before proceeding with the recovery methods, let’s understand how SQLite handles the data after deletion. When you delete a record in SQLite, it doesn’t mean that it is removed from the file. Instead:

• Once again, the space for the deleted record is marked as “free” and can be used by some future writes.
• SQLite doesn’t overwrite the data right away. It could still be inside the database file before SQLite uses that space again.
• This delayed deletion approach allows partial recovery of the data if immediate actions are taken before further modifications in the database.

This makes SQLite perfect for recovery attempts when data has recently been deleted because it may remain in the unallocated space for some time.

Methods to Recover Deleted Records in SQLite

You can follow the given methods to recover the deleted records in SQLite database.

Method 1 – Use SQLite’s Write-Ahead Logging (WAL) File

When SQLite is using Write-Ahead Logging (WAL), the database maintains a WAL file containing recent transactions not yet committed to the database file. The WAL may contain copies of data pages containing records deleted recently.

Note: This works great if the deletion happened recently and the WAL file hasn’t been overwritten by new transactions.

To try to recover using the WAL file:

• Identify the WAL file: It’s usually located in the same directory as the main database file and named “database_name-wal”.
• Copy and backup the database and WAL files. This will ensure that no further changes occur in your original files if something goes wrong.
• Open the WAL file manually with any tool of choice, preferably a hex editor or SQLite Viewer, in order to find only the records that have been deleted.
• Extract Data: Fetch the uncommitted data directly from the WAL file itself. It contains the deleted records.

Method 2 – Use SQLite Deleted Records Recovery Tools

If the other methods are too cumbersome and you don’t have a backup to go back to, you can use professional recovery software. SysTools SQLite Recovery Tool is an advanced software that is designed to scan both the allocated and unallocated space of a SQLite database file and recover deleted records.

Make sure to download and try the free demo version first. It will preview your deleted records in its interface. If everything is there as you desire, then purchase the full version.

Steps to Recover Deleted Records in SQLite using SysTools Software

• Download, install, and launch the software on your system.
• On the software’s interface, click on the Add button.

• Click on the Browse button to locate and open the SQLite database file (.sqlite, .sqlite2, .sqlite3, .db, or .db3 format) that contains the deleted records.

• The software scans the entire database and shows a preview of all recoverable items including the deleted records.

• Go to the Export option in the ribbon bar.

• Now, you can recover deleted records in SQLite database along with all other elements without any issue.

• If you want to export only the deleted records, then go to the Deleted tab, select the records that you want to recover, and save them using the tab-oriented Export button.

• Once the process completes a confirmation message will appear. Go and find the recovered deleted records in the selected format and location.

Another alternative is using the SQLite Forensics Tool. This is one of the most common tools in digital forensics for recovering deleted records by accessing low-level SQLite data structures.

Note: These tools are easy to use as they are based on graphic interfaces. Plus, the step-by-step wizard makes the recovery process painless.

Method 3 – Use Data Carving Techniques Manually

Data carving is a process in which deleted or corrupted data is extracted without depending on file system structures. This method is quite similar to the 1st method. Here, you will have to directly delve into the SQLite database file and manually parse and analyze them for records that may reside in unallocated space.

1. Open the SQLite database file using a hex editor and look for recognizable patterns in records or keywords.
2. The records are, more often than not, bearing identifiable structures in the schema format. Knowledge of the schema layout goes a long way in identifying matching fields and data types of deleted records.
3. After locating the record, manually copy and reconstruct the data. This process is quite cumbersome and time-consuming, so it’s recommended for technically-sound users or when there are no other options available.

Method 4 – Use Backup Files

This is the safest and most reliable way to recover deleted records in SQLite. IF & ONLY IF, regular backups of the SQLite database are maintained.

Some systems and mobile apps create an automatic backup of SQLite databases from time to time. Look for the relevant backup files in the storage folders of these applications.

This approach minimizes the complexity of recovery while assuring that restored data is already in a usable format. All of this without requiring manual extraction or other advanced techniques.

FAQs

Q) What are the best practices to prevent data loss in SQLite?

Here are some of the best practices:

• WAL Mode Enable: This turns on a separate log file that maintains the most recent changes, including deletions, until the database is checkpointed. The use of a WAL can often act in lieu of a backup for recent data.
• Backup Regularly: Automate frequent backups to external storage devices to ensure you have restore points.
• Version Control: Use version control of some sort with your important SQLite files. That way, you are afforded the facility to roll back into earlier versions when something goes wrong.

Q) How does SysTools software help in recovering SQLite deleted records?

It scans the SQLite database file and recovers everything, including deleted records, without losing data integrity.

Q) Can I recover data after VACUUM?

VACUUM command rebuilds the database structure and permanently overrides unallocated data. This makes it much harder to recover deleted records in SQLite. Specialized tools may come in handy in such a case.

Conclusion

Recovery of deleted records in SQLite is difficult, but it is quite feasible using proper techniques. Some of the most profound techniques include the use of the WAL file, recovery and forensic tools, data carving, and backups, where they may exist. You can enhance your likelihood of recovering data successfully by knowing the peculiar ways SQLite treats deletions and free space. Moreover, good practices like regular backups and enabling the WAL mode will protect the data.