Error Logging Interface
\ void sqlite3_log(int iErrCode, const char *zFormat, ...);\
The sqlite3_log() interface writes a message into the error log established by the SQLITE_CONFIG_LOG option to sqlite3_config(). If logging is enabled, the zFormat string and subsequent arguments are used with sqlite3_snprintf() to generate the final output string.
The sqlite3_log() interface is intended for use by extensions such as virtual tables, collating functions, and SQL functions. While there is nothing to prevent an application from calling sqlite3_log(), doing so is considered bad form.
The zFormat string must not be NULL.
To avoid deadlocks and other threading problems, the sqlite3_log() routine will not use dynamically allocated memory. The log message is stored in a fixed-length buffer on the stack. If the log message is longer than a few hundred characters, it will be truncated to the length of the buffer.