How to Solve Calibre Issues with Kobo Database Corruption

calibre_kobo_database_fix.md

Problem

When attempting to connect a Kobo device to Calibre, the following error may occur:

ERROR: Error: Error communicating with device

CorruptError: database disk image is malformed

Traceback (most recent call last):
  File "calibre\gui2\device.py", line 112, in run
  File "calibre\gui2\device.py", line 566, in _books
  File "calibre\devices\kobo\driver.py", line 2091, in books
  File "C:\t\t\apsw-42s16m2x\src\cursor.c", line 240, in resetcursor
apsw.CorruptError: CorruptError: database disk image is malformed

This occurs when the KoboReader.sqlite database is corrupted or contains invalid entries.

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Solution

1. Open the Database in SQLite Tool:

   • Use SQLiteBrowser or another SQLite tool to open the KoboReader.sqlite database.

2. Export the Database to SQL:

   • Use the tool's export functionality:

     File > Export > Database to SQL file
     

   • This creates a plain-text SQL file that includes the database schema and data.

3. Inspect and Edit the SQL File:

   • Open the exported SQL file in a text editor.
   • Look for invalid entries or table definitions. The issue I've encountered was invalid default values, such as:

     "WishlistedDate" TEXT DEFAULT 0000-00-00T00:00:00.000,
     "DateModified" TEXT DEFAULT 0000-00-00T00:00:00.000,

   • These values are invalid in SQLite because they lack quotes around the default date values.

4. Fix the SQL File:

   • Correct invalid lines by wrapping default values in quotes:

     "WishlistedDate" TEXT DEFAULT '0000-00-00T00:00:00.000',
     "DateModified" TEXT DEFAULT '0000-00-00T00:00:00.000',

5. Reimport the SQL File:

   • In the SQLite tool, create a new database and import the corrected SQL file:

     File > Import > Database from SQL file
     

6. Replace the Corrupted Database:

   • Replace the original KoboReader.sqlite file on the device with the repaired version.

7. Verify and Test:

   • Run PRAGMA integrity_check; on the new database to confirm it is valid.
   • Reconnect the Kobo to Calibre and ensure the device is detected correctly.