Can't insert new Library::Book: DBD::mysql::st execute failed: 
Column 'id' cannot be null [for Statement "INSERT INTO book (name, author, id) VALUES (?, ?, ?)"]
at
/usr/local/lib/perl5/site_perl/5.8.5/DBIx/ContextualFetch.pm line 51, <GEN2> line 7. 
at 
/usr/local/lib/perl5/site_perl/5.8.5/Class/DBI/FromCGI.pm line 246