Hello, I would like to hear some feedback on this DBI API proposal. Tim, what is opinion for adding that new diagnostic API into DBI?
On Tuesday 29 January 2019 13:16:23 p...@cpan.org wrote: > CCing DBD::Pg, DBD::Oracle and DBD::ODBC developers. What do you think > about following diagnostic API in DBI? > > I looked at DBD::Pg and currently it does not support retrieving > warnings via $dbh->errstr or $dbh->state methods... So I think it that > my diagnostic API proposal can be useful for DBD::Pg too. > > On Wednesday 23 January 2019 11:15:35 p...@cpan.org wrote: > > Hi! DBI currently supports 3 functions to retrieve diagnostic > > informations > > > > https://metacpan.org/pod/DBI#err > > https://metacpan.org/pod/DBI#errstr > > https://metacpan.org/pod/DBI#state > > > > which return the last one database native code, message and SQLSTATE. > > Plus there warning or note information is indicated by zero native code > > or by empty string in native code. > > > > This API has two big limitations: > > > > 1) It does not support providing database native code for warnings and > > note informations. > > > > 2) It does not support providing more warnings, errors or note > > informations. > > > > It most cases database native code is what application can "parse" and > > decide how to handle it. So absence of database native code for warnings > > or note informations can be a problem -- as currently DBI application > > needs to parse string message from $dbh->errstr. > > > > Also databases can return more warnings or note informations for the > > last executed call. For this case DBI defines API for errstr just as: > > > > "The returned string may contain multiple messages separated by newline > > characters." > > > > So it is harder for DBI application to parse multi warnings. And there > > is not information for which warning is value from $dbh->state. > > > > > > > > Based on above two limitations I would like to propose a new API for > > diagnostic messages (errors, warnings and note / success with > > information). > > > > New method call "get_diagnostics()" for all DBI handles. It would > > return array of diagnostics member. Each diagnostic member would contain > > reference to array with 4 members: type, native code, message, sqlstate. > > > > Type can be non-zero for errors, zero for warnings and empty string for > > notes / success with information. Like what $dbh->err now returns. > > > > Native code is native database code, same what $dbh->err returns for > > errors. But for warnings and notes it would also contain database native > > code, not just false value > > > > Message and sqlstate would return $dbh->errstr and $dbh->state. > > > > Example of usage: > > > > my @array = $dbh->get_diagnostics(); > > foreach (@array) { > > my ($type, $code, $message, $sqlstate) = @{$_}; > > if ($type) { > > print "Error $code ($sqlstate): $message\n"; > > } elsif ($type eq '0') { > > print "Warning $code ($sqlstate): $message\n"; > > } else { > > # Process success with information message > > } > > } > > > > What do you think about it?
