Sqlite Error and Warning Log

In the last blog we discussed about how to recover the Sqlite database File, now this time we will cover the types of Sqlite error and warning log we get in Sqlite database. At the time of occurrence of anomalies in Sqlite, it can be configured to evoke a callback function that contains an error and terse error code. This leads the application developers to take full advantage of the error logging facility in their applications. These facilities consume very less memory and are of great importance for debugging.

Creating An Error Log Callback

For a process there can be only a single error logging callback function. An error logging callback function is usually generated with C-code at the start-time. An example of an error callback function is:

void errorLogCallback(void *pArg, int iErrCode, const char *zMsg){ fprintf(stderr, “(%d) %s\n”, iErrCode, zMsg);}

Messages on stderr are usually not printed in embedded applications. They are stored in a circulated buffer from which they can be later on accessed at the time of debugging. Also the messages can also be sent to Syslog, they should be stored in such a way that they are accessible to the developers but not to the end users or viewers. This is because these messages are highly technical and are of no importance to the viewers.

Kinds Of Sqlite Error Messages

The format of the error messages that are sent to the error logger can change depending on the release of Sqlite. Therefore it is advised that the application developers should not indulge in a specific text format of error message or error code. Different kinds of messages that are displayed in the error callback are:

• Whenever there is an error when a SQL statement is compiled or is run, the error message is being logged.
• When a schema is changed that requires a statement to be prepared again, the event with error code named SQLITE_SCHEMA gets logged
• Whenever a writer gets crashed before finishing off a transaction, error messages named SQLITE_NOTICE are logged.
• When database names are changed or modified such that they may lead to corruption, message SQLITE_WARNING gets logged.
• Error logging events are also generated at the time of I/O errors in the interface of operating system.
• SQLITE_CORRUPT error message is logged whenever corruption is detected.

Summary

Sqlite generates very low traffic to the error logger and an error is generated only when something is really very wrong. These errors can lead to corruption of Sqlite database in many cases. The corrupted data becomes inaccessible and cannot be recovered using any manual procedure. Therefore, the only solution left is the deployment of a third party tool like Sqlite Database Recovery. The software recovers the entire corrupted database of Sqlite. The software does not put any size limitation on the database that has to be recovered. Thus it’s a perfect solution to access corrupted Sqlite database.