- #include <libpq-fe.h>: Include the file containing
declarations of libpq functions.
- static void oops(PGconn *cnxn): A function to
clean up when things go wrong. Exit code of 1 indicates that the
program encountered a problem.
- stderr: Print on stderr because we
are describing an error.
- PGresult *res: Receive the return value
from database operations, usually an error code.
- PGconn *cnxn: The connection. Used in all database
operations.
- return 0: Exit code of 0 means that
nothing went wrong.