PostgreSQL, Second Edition

Client 2—Adding Error Checking

As mentioned earlier, libpqxx follows the STL philosophy that an error condition should be reported by throwing an exception. libpqxx defines three exception types, all derived from std::runtime_error:

• sql_error— Thrown when the PostgreSQL server reports an error

• broken_connection— Thrown when the libpqxx library detects that the connection to the server has been broken

• in_doubt_error— Thrown when you COMMIT a transaction but the connection to the server fails before libpqxx has received an acknowledgement that the COMMIT completed

Because these exception classes are ultimately derived from std::exception, each provides a member function named what() that returns a description of the error that occurred. In addition, ...