Returns an integer containing the last error number. If no error was reported 0 is returned.
If a link resource is passed to ingres_errno() it returns the last error recorded for the link. If no link is passed then ingres_errno() returns the last error reported using the default link.
The function, ingres_errno(), should always be called after executing a database query. Calling another function before ingres_errno() is called, will reset or change any error code from the last Ingres function call.
See also ingres_error() and ingres_errsqlstate().