Using DBI v 1.636 $dbi->{FetchHashKeyName}=’NAME_lc’ or NAME_uc apparently produces different keys from ‘lc’ and ‘uc’ functions for fieldnames containing non-ascii characters.
For example, ‘ämne-Abc’ with FetchHashKeyName=NAME_lc results in result key ‘\x{0}\x{0}mne-abc’ ---- Summary of my perl5 (revision 5 version 24 subversion 0) configuration: Platform: osname=linux, osvers=2.6.32-642.6.2.el6.x86_64, archname=x86_64-linux uname='linux yonkyo.local 2.6.32-642.6.2.el6.x86_64 #1 smp wed oct 26 06:52:09 utc 2016 x86_64 x86_64 x86_64 gnulinux ' config_args='-de -Dprefix=/opt/perlbrew/perls/perl-5.24.0 -Aeval:scriptdir=/opt/perlbrew/perls/perl-5.24.0/bin' hint=recommended, useposix=true, d_sigaction=define useithreads=undef, usemultiplicity=undef use64bitint=define, use64bitall=define, uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cc', ccflags ='-fwrapv -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2', optimize='-O2', cppflags='-fwrapv -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include' ccversion='', gccversion='4.4.7 20120313 (Red Hat 4.4.7-17)', gccosandvers='' intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678, doublekind=3 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16, longdblkind=3 ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8 alignbytes=8, prototype=define Linker and Libraries: ld='cc', ldflags =' -fstack-protector -L/usr/local/lib' libpth=/usr/local/lib /usr/lib /lib/../lib64 /usr/lib/../lib64 /lib /lib64 /usr/lib64 /usr/local/lib64 libs=-lpthread -lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc libc=libc-2.12.so, so=so, useshrplib=false, libperl=libperl.a gnulibc_version='2.12' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E' cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector' Characteristics of this binary (from libperl): Compile-time options: HAS_TIMES PERLIO_LAYERS PERL_COPY_ON_WRITE PERL_DONT_CREATE_GVSV PERL_HASH_FUNC_ONE_AT_A_TIME_HARD PERL_MALLOC_WRAP PERL_PRESERVE_IVUV USE_64_BIT_ALL USE_64_BIT_INT USE_LARGE_FILES USE_LOCALE USE_LOCALE_COLLATE USE_LOCALE_CTYPE USE_LOCALE_NUMERIC USE_LOCALE_TIME USE_PERLIO USE_PERL_ATOF Locally applied patches: Devel::PatchPerl 1.42 Built under linux Compiled at Nov 3 2016 12:25:49 %ENV: PERLBREW_BASHRC_VERSION="0.75" PERLBREW_HOME="/home/chris/.perlbrew" PERLBREW_MANPATH="/opt/perlbrew/perls/perl-5.24.0/man" PERLBREW_PATH="/opt/perlbrew/bin:/opt/perlbrew/perls/perl-5.24.0/bin" PERLBREW_PERL="perl-5.24.0" PERLBREW_ROOT="/opt/perlbrew" PERLBREW_VERSION="0.75" @INC: /opt/perlbrew/perls/perl-5.24.0/lib/site_perl/5.24.0/x86_64-linux /opt/perlbrew/perls/perl-5.24.0/lib/site_perl/5.24.0 /opt/perlbrew/perls/perl-5.24.0/lib/5.24.0/x86_64-linux /opt/perlbrew/perls/perl-5.24.0/lib/5.24.0 . --- Test case script ===================================== use strict; use utf8; use Test::More tests => 26; use Data::Dumper; use DBI; my $dbi=DBI->connect( 'dbi:Pg:dbname=test_db', 'chris', '', { pg_enable_utf8 => 1, } ); my @expect=( [ 'NAME', "ABc", "ABc" ], [ 'NAME_uc', "ABc", "ABC" ], [ 'NAME_lc', "ABc", "abc" ], [ 'NAME', "てすと-ABc", "てすと-ABc" ], [ 'NAME_uc', "てすと-Abc", "てすと-ABC" ], [ 'NAME_uc', "てすと-Abc", "てすと-ABC" ], [ 'NAME_lc', "てすと-Abc", "てすと-abc" ], [ 'NAME_lc', "てすと-Abc", "てすと-abc" ], [ 'NAME', "ÄMNE-Abc", "ÄMNE-Abc" ], [ 'NAME_uc', "ÄMNE-Abc", "ÄMNE-ABC" ], [ 'NAME_uc', "ämne-Abc", "ÄMNE-ABC" ], [ 'NAME_lc', "ämne-Abc", "ämne-abc" ], [ 'NAME_lc', "ÄMNE-Abc", "ämne-abc" ], ); foreach my $e (@expect) { my($case,$as,$fld)=@$e; my $val; if($case eq 'NAME_uc') { $val = uc($as); } elsif($case eq 'NAME_lc') { $val = lc($as); } else { $val = $as; } is($val,$fld,"case-converted $as to $case"); $dbi->{FetchHashKeyName} = $case; my $row=$dbi->selectrow_hashref(qq{ select now() as "$as" }); ok(exists $row->{$fld},"hashref $case") or diag(Dumper $row); } Regards, Chris Hutchinson