All DB-related errors manifest themselves as exceptions of type soci_error, which is derived from std::runtime_error.
This allows to handle database errors within the standard exception framework:
int main()
{
try
{
// regular code
}
catch (std::exception const & e)
{
cerr << "Bang! " << e.what() << endl;
}
}
The only public method of soci_error is std::string get_error_message() const, which returns just the brief error message, without any additional information that can be present in the full error message returned by what().
The Oracle backend can also throw the instances of the oracle_soci_error, which is publicly derived from soci_error and has an additional public err_num_ member containing the Oracle error code:
int main()
{
try
{
// regular code
}
catch (soci::oracle_soci_error const & e)
{
cerr << "Oracle error: " << e.err_num_
<< " " << e.what() << endl;
}
catch (soci::exception const & e)
{
cerr << "Some other error: " << e.what() << endl;
}
}
The MySQL backend can throw instances of the mysql_soci_error, which is publicly derived from soci_error and has an additional public err_num_ member containing the MySQL error code (as returned by mysql_errno()):
int main()
{
try
{
// regular code
}
catch (soci::mysql_soci_error const & e)
{
cerr << "MySQL error: " << e.err_num_
<< " " << e.what() << endl;
}
catch (soci::exception const & e)
{
cerr << "Some other error: " << e.what() << endl;
}
}
The PostgreSQL backend can also throw the instances of the postgresql_soci_error, which is publicly derived from soci_error and has an additional public sqlstate() member function returning the five-character "SQLSTATE" error code:
int main()
{
try
{
// regular code
}
catch (soci::postgresql_soci_error const & e)
{
cerr << "PostgreSQL error: " << e.sqlstate()
<< " " << e.what() << endl;
}
catch (soci::exception const & e)
{
cerr << "Some other error: " << e.what() << endl;
}
}