Database Error

Sometimes, you may see the following error message:

This indicates that a database error has occurred, and it is recommended to handle it immediately.

What happened?

WonderPen’s library content is stored in a SQLite database. Generally speaking, SQLite is very reliable, but if multiple programs read and write to it, there is a certain probability of errors. For example, if you put a local library into a third-party cloud drive, and the third-party cloud drive has a conflict during synchronization, it may corrupt the database file.

Don’t panic when encountering this problem. WonderPen has built-in automatic data backup enabled by default. Database corruption will not affect existing backup files, and you can restore data from backups at any time.

How to handle it?

There are usually three ways to handle database errors.

1️⃣ Exit and restart WonderPen

Sometimes, this error is temporary, and exiting and restarting WonderPen can restore normal operation.

If the error still appears after restarting, please continue with the methods below.

2️⃣ Restore from backup

In most cases, you can try to restore from backup, which may fix the database.

As shown in the figure above, open the backup and restore panel, and click the restore button on the right side of the latest backup to restore the data.

If no error message appears after restoring the data, it means the database has returned to normal.

If you still see error messages, please try the method below.

3️⃣ Delete the local database file, then restore from backup

If direct restoration cannot fix the database, you need to first delete the local database file (or, more safely: rename it or move it to another location), and then try to restore from backup.

The specific steps are as follows:

Exit WonderPen

To delete the current library database, you need to exit WonderPen first, otherwise the database file may still be in use and deletion may fail.
Open the library folder

Open the folder where the current library is located. Library folders generally end with .wplibrary.
Delete (or rename, move) the database file

In the library folder (.wplibrary folder), you should be able to see a data.db file. The directory structure is similar to the following:
```
My Library.wplibrary/
├── assets/
├── backup/
├── db/
├── data.db  <-- Focus on this file
└── ...
```
Note that there may be other files in your library directory, but you don’t need to pay attention to other files, just focus on that data.db file.

If your system hides file extensions, you may only see a file named data.

Next, you can delete this data.db file. Of course, to be safe, you can also rename this file or move it to another location so that you can restore it if needed.

If you see other files starting with data in this directory, such as data.db-shm, data.db-wal, you can delete (or rename, move) them together.
Open WonderPen and restore from backup again

Then, please reopen WonderPen and open this library. At this time, the library should appear empty.

Finally, please restore from backup again, and the library should return to normal.

Still having problems?

If you still encounter problems, please contact us via Email or other methods.

More information

Some common error codes:

code	Meaning	Common scenarios
`SQLITE_INTERNAL`	Internal logic error	SQLite internal bug (very rare)
`SQLITE_PERM`	Permission error	Unable to write to database file
`SQLITE_ABORT`	Operation aborted	Transaction manually aborted
`SQLITE_BUSY`	Database locked	Multiple processes writing to database simultaneously
`SQLITE_LOCKED`	Database file lock conflict	Lock contention within the same connection
`SQLITE_NOMEM`	Out of memory	Insufficient system resources
`SQLITE_READONLY`	Read-only database	Database opened in read-only mode
`SQLITE_IOERR`	I/O error	Disk read/write error
`SQLITE_CORRUPT`	Database corrupted	File corruption, “database disk image is malformed”
`SQLITE_NOTFOUND`	File not found	Database or index missing
`SQLITE_FULL`	Disk full	Write failed
`SQLITE_CANTOPEN`	Unable to open database	File path error or insufficient permissions
`SQLITE_EMPTY`	Database empty	Reading empty file
`SQLITE_TOOBIG`	Data too large	Inserting very long string or blob
`SQLITE_NOLFS`	Large file not supported	Rare case
`SQLITE_FORMAT`	File format error	SQLite version incompatibility
`SQLITE_NOTADB`	Not a SQLite file	The opened file is not a database