I'm having an issue with a new application on the iPhone SDK using SQLite as the DB backend.
Occasionally, my app will stop loading data to my UITableViews and after downloading the device DB via the Organizer I can access the SQLite DB via the command line. I can query certain tables fine but not others without getting an "SQL error: database disk image is malformed" error. See a sqlite session below:
SQLite version 3.6.17
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> select * from user;
1|[email protected]|cpjolicoeur||4d055e38bb1d3758|image/gif|cartoonme_avatar.gif||Craig|Jolicoeur|1|1
sqlite> select * from item;
SQL error: database disk image is malformed
sqlite>
In this example my user table works fine but my item table is malformed, which corresponds with what I am seeing in my app where the items dont load. The app doesnt crash, the data just doesnt load because of this malformed error.
Any ideas why this is happening? My only thought is that maybe the DB is being corrupted because I am writing to the SQLite DB via a background thread within the app. I download data from a webserver via an NSOperationQueue in a background thread and update the SQLite DB with the data downloaded. Would writing to the DB in a background thread (while potentially reading from the main thread) corrupt the DB, or is it something else?