My apologies. I am seeing this behavior with DBD::Oracle versions 1.17 and 1.22
----- Original Message ----- From: "John Scoles" To: "Milo van der Leij" Cc: dbi-dev@perl.org Subject: Re: DBD::Oracle - is ora_lob_read mangling BLOB data? Date: Thu, 26 Mar 2009 06:43:32 -0400 Can you tell us which version of DBD::Oracle you are using. There is quite a differance between versions when it comes to UTF8 handling. Milo van der Leij wrote: > I am in the progress of changing some code that uses DBD::Oracle > to use the documented ora_lob_read function instead of the > undocumented blob_read, and I suddenly hit the error "Malformed > UTF-8 character (unexpected end of string) in length". > > As it turns out, Perl's length function returns the number of > characters in the string. If Perl thinks the string contains > text and the text is in utf-8, then this can be different from > the number of bytes in the string. I regret to say that I am > very unfamiliar with how Perl handles utf-8, but I am familiar > enough with Oracle to see that treating BLOB data as character > data is incorrect. > > I see the call to SvUTF8_on in ora_lob_read in Oracle.xs, I see > how the value of NLS_LANG plays in, and I see how it affects both > CLOB and BLOB data, so I understand why I am getting the result I > am getting. But I have some questions: > > (For someone who understands utf-8 in Perl:) Is there danger in > binary data being treated as utf-8, other than the length > function crashing? Is there a workaround? (I see "use bytes", > but Perl 5.10 doc for the length function says "the internal > encoding is variable, and the number of bytes usually > meaningless" which scares me.) > > (For someone who understands the stuff in Oracle.xs:) Is it even > possible to change ora_lob_read to only call SvUTF8_on for CLOB > data and not for BLOB data? > > My test case is included below. Connection info will need to be > altered before it runs. Commenting out the line with AL32UTF8 > makes the problem go away. > > use strict; > use DBI; > use DBD::Oracle qw(:ora_types); > > $ENV{'NLS_LANG'} = '_.AL32UTF8'; > my $hDB = DBI->connect('dbi:Oracle:TEST', 'SCOTT', 'TIGER'); > > my $hSQL = $hDB->prepare(qq{ > DECLARE > b blob; > BEGIN > dbms_lob.createtemporary(b,true); > dbms_lob.writeappend(b,256,utl_raw.xrange('00','FF')); > :b := b; > END; > }, { ora_auto_lob => 0 }); > > my $b; > $hSQL->bind_param_inout( ':b', \$b, 0, { ora_type => ORA_BLOB } ); > $hSQL->execute; > > my $data = $hDB->ora_lob_read( $b, 1, 1024 ); > print "Read ", length($data), " bytes.\n"; > > > -- Be Yourself @ mail.com! Choose From 200+ Email Addresses Get a Free Account at www.mail.com