On 18/11/10 20:24, Martin J. Evans wrote:
> On 18/11/2010 20:15, Steve Baldwin wrote:
>> Hi,
>>
>> I ran across an issue recently that appears to have existed for quite some
>> time.
>>
>> Consider the following script ...
>>
>> #!/usr/bin/perl -w
>> use strict;
>> use warnings;
>> use DBI;
>>
>> sub main {
>> my $dbh = DBI->connect(
>> 'dbi:Oracle:',
>> 'usr/pwd@conn',
>> '',
>> { PrintError => 0, AutoCommit => 0, RaiseError => 1 },
>> );
>> my $sql =<<'END_SQL';
>> SELECT 1 srt, 'AA' txt
>> FROM dual
>> UNION
>> SELECT 2, 'BBB'
>> FROM dual
>> UNION
>> SELECT 3, 'CCCC'
>> FROM dual
>> ORDER
>> BY 1
>> END_SQL
>> my $sth = $dbh->prepare($sql);
>> $sth->execute;
>> my ($srt, $txt);
>> $sth->bind_columns(\($srt, $txt));
>> while ($sth->fetch) {
>> print "[$srt][$txt] len=" . (length($txt)) . "\n";
>> }
>> $dbh->disconnect;
>> return 0;
>> }
>>
>> exit main();
>>
>> Running it produces the following output :
>>
>> au-stb-101-144:dev stbaldwin$ ./sb2.plx
>> [1][AA] len=2
>> [2][BBB] len=2
>> [3][CCCC] len=2
>>
>> As you can see, even though the data in $txt looks correct, perl thinks the
>> internal length of the variable is whatever it was after fetching the first
>> row. This screws up things like sprintf.
>>
>> I'm pretty sure this behaviour is a DBD::Oracle thing rather than a DBI
>> thing. I tried an equivalent script with DBD::SQLite and DBD::mysql and
>> they both returned the length correctly (imo).
>>
>> This behaviour exists in 1.23 and 1.26. I haven't tested any other
>> versions.
>>
>> Thanks,
>>
>> Steve
>
> I vaguely remember hitting this issue myself some time ago. Perhaps a search
> of dbi-users or dbi-dev will find something. I'll try and dig out a reference
> tomorrow.
>
> Martin
>
I suddenly remembered what is probably causing this as I hit a similar problem
in DBD::ODBC. It was failing to set magic on the sv for the bound column. This
should probably be reported in the rt system for DBD::Oracle. I don't have time
right now to look into it and will probably forget again unless it is rt'ed.
Martin
--
Martin J. Evans
Easysoft Limited
http://www.easysoft.com
