Repair SQLite Database and Restore SQLite Database Objects

Are you using SQLite Browser? Since how long have you been using it? Have you ever confronted corruption in your SQLite database or any other issue that leads to data loss? Like any other database programs, SQLite is prone to crash or malfunction due to the internal bugs. And like every other database files, an SQL database is also not immune to corruption. Whatever the reason is, be it SQLite crash or corruption, it’ll result in data loss. Thankfully, there’s an easy manual trick to repair SQLite database at the time of corruption or SQLite crash. I’ll share the trick later in this post. Also, we’ll read about a professional solution that helps you when the manual trick fails or doesn’t work.

SQLite – An Introduction

SQLite works as an in-process library that has a self-contained, serverless, zero-configuration, and transactional SQL database engine. It’s a part of C programming library. Though SQLite is a relational database management system (DBMS), it’s not a client-server database engine. In fact, it’s embedded into the end program. Over the last decade, SQLite has become a popular choice as embedded database software for both local as well as client storage in application software. It’s the most deployed database engine used by various browsers, operating systems, embedded systems (like mobile phones), etc.

 Also Read: Best Solution to Fix SQLite Error Malformed Database Schema

SQLite Database

Unlike other SQL database, it reads and writes directly to the ordinary disk files. A single disk file contains complete SQL database with multiple tables, indices, triggers, and views. Things you should know about SQLite database:

• SQLite database uses two formats, i.e. UTF-8 (ANSI) and UTF-16 (Unicode), to store data.
• There are two versions of SQLite database: SQLite2 and SQLite3.
• It uses a more general dynamic system type. The datatype of a value is associated with the value itself, not with its container.
• In SQLite database, each value has one of these storage classes: NULL, INTEGER, REAL, TEXT, and BLOB.

SQLite Database Corruption

As I mentioned earlier, SQLite database is prone to corruption like any other database file. There are various reasons which can cause SQLite database corruption and lead to permanent data loss. Let me show you some very common scenarios which may cause corruption and lead to data loss: Overwriting the SQLite database SQLite database is an ordinary disk file, so overwriting is possible. And there’s no way to defend the SQLite database from overwriting. This may cause some serious issues, such as:

Overwriting the SQLite database

SQLite database is an ordinary disk file, so overwriting is possible. And there’s no way to defend the SQLite database from overwriting. This may cause some serious issues, such as:

• Running file decryptor: Opening and closing a decryptor, again and again, may overwrite the threads which are managed on SQLite log files. Such an inappropriate action may replace the data and cause corruption.
• Restore while a transaction is in running mode: Running a backup job at the back-end of the system may create a backup of SQLite database. Since the transaction is not successfully completed, the backup job will save some logs of the previous state and some logs of earlier transactions. As a result, the transaction’s ID doesn’t match and it leads to corruption.
• Delete Hot journal: For database recovery, SQLite uses auxiliary journal files. But if you rename, delete or move these journal files from their actual location, Server fails to find them. As a result, the automatic database recovery can’t be performed.

Locking the SQLite database

Sometimes unwanted changes made by two different processes for a single database may cause corruption and other issues. To avoid that, you can lock the SQLite database files. SQLite provides you a feature for this. But sometimes this helpful feature can itself cause serious problems:

• Missing lock details: Some file systems are treated as reliable sources for locking SQLite database. They might have some irresolvable internal bugs which may cause missing lock details. Whenever an SQLite database gets locked and the lock details are missing, corruption takes place.
• Protocols’ contradiction: SQLite3_vfs and SQLite3_open_v2() are two protocols well-known for SQLite database handling. If you’re working on an SQLite database with both these protocols at the same time, you’ll face the contradiction.
• Using multiple links to a single file: If you’re adding multiple links into a single SQLite database with network connectivity, this may cause SQLite database corruption.
• Renaming or unlinking the database: Renaming any file of SQLite database which is not present at the same location, may cause unlinking in the SQLite database and may result in corruption.

 Also Read: SQLite Error Database is Locked – How to Fix It

Synchronizing SQLite database

You should only use the sync command to perform SQLite database synchronization. But if you use it an I/O barrier, this will lead to any failure rolling back the actions further. It may result in ACID (Atomicity, Consistency, Isolation, Durability) property violation which will lead to SQLite database corruption.

Some other reasons for SQLite database corruption are bugs attack, virus infection, storage media failure, software malfunction, sudden power failure, etc.

Fix SQLite database corruption 

SQLite database corruption leads to permanent data loss. Since you can’t open the corrupt SQLite database, you just can’t access its data until unless you repair it. Before you can try to repair SQLite database, you can use the backup file to restore SQLite data. But make sure you’ve taken backup of SQLite database earlier. But if you have no valid backup for your SQLite database, you have only two options: either you can try to repair SQLite database manually or you can use a professional recovery solution for SQLite data recovery.

Repair SQLite Database

Luckily, there’s a manual trick that can help you repair SQLite database without using any 3rd party tool. But keep it in mind that the manual trick can only fix minor corruption issues. In the case of severe corruption, it may fail or not work up to the mark. Follow the steps given below to repair SQLite database manually:

Step 1: First of all, launch DB Browser for SQLite on your system. Then click Execute SQL tab to run database check command.

Step 2: Now type PRAGMA integrity_check in the command prompt. Then click the Play button.

Since the SQLite database is corrupt, you’ll see an error reporting the issue.

Step 3: Now click the File tab on the task bar. Point to Export in the options and click Database to SQL file…

Step 4: On the Export SQL… dialog box, select the objects which you want to export. Define other options as well. After that, click OK to export the objects.

Step 5: Now, import the database file back to SQLite browser. For that, click the File tab on the task bar. Point to Import in the options and click Database from SQL file… This will resolve the issue in a case of minor corruption.

This will resolve the issue in a case of minor corruption. But if corruption is severe, the above manual trick may fail or not work. In such a situation, you should use a professional recovery solution.

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SQLite Database Recovery Software

SQLite Database Recovery software is smart SQLite data recovery solution recommended by professionals and data recovery experts. It can successfully fix SQLite database corruption and repair SQLite database without causing any alteration to the original data. It supports corrupt SQLite database file created by both SQLite2 and SQLite3. Via this software, you can restore SQLite database objects like tables, indices, views, triggers, etc. and save them into a new database file. The Column mapping feature in this software helps you save the recovered data from SQLite to MDB file format. Before purchasing the software, you should download its demo version for free evaluation. By using demo version, you can check a preview of your SQLite data which you can actually recover from the corrupt SQLite database before you pay for the software.

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