From: Rafael Kitover Date: Fri, 8 Apr 2011 17:52:49 +0000 (-0400) Subject: handle BLOB and CLOB columns in WHERE for Oracle X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=00a281880b14e3b245df11f476983277e1713829;p=dbsrgits%2FDBIx-Class-Historic.git handle BLOB and CLOB columns in WHERE for Oracle --- diff --git a/Changes b/Changes index b2a151e..32559b7 100644 --- a/Changes +++ b/Changes @@ -22,6 +22,8 @@ Revision history for DBIx::Class - Support ancient DB2 versions (5.4 and older), with proper limit dialect - Support sub-second precision for TIMESTAMPs for Firebird over ODBC + - Support BLOBs and CLOBs in WHERE clauses for Oracle, including LIKE + queries for CLOBs. * Fixes - Fix ::Storage::DBI::* MRO problems on 5.8.x perls diff --git a/lib/DBIx/Class/Storage/DBI.pm b/lib/DBIx/Class/Storage/DBI.pm index 1c7ea76..04c33c1 100644 --- a/lib/DBIx/Class/Storage/DBI.pm +++ b/lib/DBIx/Class/Storage/DBI.pm @@ -1683,7 +1683,7 @@ sub _dbi_attrs_for_bind { for (map { $_->[0] } @$bind) { push @attrs, do { - if ($_->{dbd_attrs}) { + if (exists $_->{dbd_attrs}) { $_->{dbd_attrs} } elsif($_->{sqlt_datatype}) { diff --git a/lib/DBIx/Class/Storage/DBI/Oracle/Generic.pm b/lib/DBIx/Class/Storage/DBI/Oracle/Generic.pm index 4bca652..50867e5 100644 --- a/lib/DBIx/Class/Storage/DBI/Oracle/Generic.pm +++ b/lib/DBIx/Class/Storage/DBI/Oracle/Generic.pm @@ -5,6 +5,7 @@ use warnings; use Scope::Guard (); use Context::Preserve 'preserve_context'; use Try::Tiny; +use List::Util 'first'; use namespace::clean; __PACKAGE__->sql_limit_dialect ('RowNum'); @@ -82,6 +83,8 @@ use mro 'c3'; __PACKAGE__->sql_maker_class('DBIx::Class::SQLMaker::Oracle'); __PACKAGE__->datetime_parser_type('DateTime::Format::Oracle'); +sub __cache_queries_with_max_lob_parts { 2 } + sub _determine_supports_insert_returning { my $self = shift; @@ -279,7 +282,16 @@ sub _dbh_execute { my $next = $self->next::can; do { try { - my $exec = sub { $self->$next($dbh, $sql, @args) }; + my $exec = sub { + # Turn off sth caching for multi-part LOBs. See _prep_for_execute above. + local $self->{disable_sth_caching} = 1 + if first { + ($_->[0]{_ora_lob_autosplit_part}||0) + > (__cache_queries_with_max_lob_parts-1) + } @{ $args[0] }; + + $self->$next($dbh, $sql, @args) + }; if (!defined $want) { $exec->(); @@ -400,6 +412,7 @@ sub connect_call_datetime_setup { # sub _dbi_attrs_for_bind { my ($self, $ident, $bind) = @_; + my $attrs = $self->next::method($ident, $bind); for my $i (0 .. $#$attrs) { @@ -435,6 +448,110 @@ sub bind_attribute_by_data_type { } } +# Handle blob columns in WHERE. +# +# For equality comparisons: +# +# We split data intended for comparing to a LOB into 2000 character chunks and +# compare them using dbms_lob.substr on the LOB column. +# +# We turn off DBD::Oracle LOB binds for these partial LOB comparisons by passing +# dbd_attrs => undef, because these are regular varchar2 comparisons and +# otherwise the query will fail. +# +# Since the most common comparison size is likely to be under 4000 characters +# (TEXT comparisons previously deployed to other RDBMSes) we disable +# prepare_cached for queries with more than two part comparisons to a LOB +# column. This is done in _dbh_execute (above) which was previously overridden +# to gracefully recover from an Oracle error. This is to be careful to not +# exhaust your application's open cursor limit. +# +# See: +# http://itcareershift.com/blog1/2011/02/21/oracle-max-number-of-open-cursors-complete-reference-for-the-new-oracle-dba/ +# on the open_cursor limit. +# +# For everything else: +# +# We assume that everything that is not a LOB comparison, will most likely be a +# LIKE query or some sort of function invocation. This may prove to be a naive +# assumption in the future, but for now it should cover the two most likely +# things users would want to do with a BLOB or CLOB, an equality test or a LIKE +# query (on a CLOB.) +# +# For these expressions, the bind must NOT have the attributes of a LOB bind for +# DBD::Oracle, otherwise the query will fail. This is done by passing +# dbd_attrs => undef. + +sub _prep_for_execute { + my $self = shift; + my ($op) = @_; + + my ($sql, $bind) = $self->next::method(@_); + + return ($sql, $bind) if $op ne 'select'; + + my @sql_part = split /\?/, $sql; + my ($new_sql, @new_binds); + + foreach my $bound (@$bind) { + my $data_type = $bound->[0]{sqlt_datatype}||''; + + if ($self->_is_lob_type($data_type)) { + if (my ($col, $eq) = $sql_part[0] =~ /(?<=\s)([\w."]+)(\s*=\s*)$/) { + my $data = $bound->[1]; + + $data = "$data" if ref $data; + + my @parts = unpack '(a2000)*', $data; + + my @sql_frag; + + for my $idx (0..$#parts) { + push @sql_frag, +"UTL_RAW.CAST_TO_VARCHAR2(RAWTOHEX(DBMS_LOB.SUBSTR($col, 2000, ".($idx*2000+1)."))) = ?"; + } + + my $sql_frag = '( ' . (join ' AND ', @sql_frag) . ' )'; + + $sql_part[0] =~ s/(?<=\s)([\w."]+)(\s*=\s*)$/$sql_frag/; + + $new_sql .= shift @sql_part; + + for my $idx (0..$#parts) { + push @new_binds, [ + { + %{ $bound->[0] }, + _ora_lob_autosplit_part => $idx, + dbd_attrs => undef, + }, + $parts[$idx] + ]; + } + } + else { + $new_sql .= shift(@sql_part) . '?'; + + push @new_binds, [ + { + %{ $bound->[0] }, + dbd_attrs => undef, + }, + $bound->[1], + ]; + } + } + else { + $new_sql .= shift(@sql_part) . '?'; + push @new_binds, $bound; + } + } + $new_sql .= join '', @sql_part; + + return ($new_sql, \@new_binds); +} + +# Savepoints stuff. + sub _svp_begin { my ($self, $name) = @_; $self->_get_dbh->do("SAVEPOINT $name"); @@ -588,7 +705,7 @@ It uses the same syntax as L =head1 AUTHOR -See L. +See L and L. =head1 LICENSE @@ -597,3 +714,4 @@ You may distribute this code under the same terms as Perl itself. =cut 1; +# vim:sts=2 sw=2: diff --git a/t/73oracle.t b/t/73oracle.t index ca30810..bbee812 100644 --- a/t/73oracle.t +++ b/t/73oracle.t @@ -4,6 +4,7 @@ use warnings; use Test::Exception; use Test::More; use Sub::Name; +use Try::Tiny; use lib qw(t/lib); use DBICTest; @@ -375,19 +376,18 @@ sub _run_tests { my %binstr = ( 'small' => join('', map { chr($_) } ( 1 .. 127 )) ); $binstr{'large'} = $binstr{'small'} x 1024; - my $maxloblen = length $binstr{'large'}; + my $maxloblen = (length $binstr{'large'}) + 5; note "Localizing LongReadLen to $maxloblen to avoid truncation of test data"; local $dbh->{'LongReadLen'} = $maxloblen; my $rs = $schema->resultset('BindType'); - my $id = 0; if ($DBD::Oracle::VERSION eq '1.23') { throws_ok { $rs->create({ id => 1, blob => $binstr{large} }) } qr/broken/, 'throws on blob insert with DBD::Oracle == 1.23'; - skip 'buggy BLOB support in DBD::Oracle 1.23', 7; + skip 'buggy BLOB support in DBD::Oracle 1.23', 1; } # disable BLOB mega-output @@ -398,14 +398,36 @@ sub _run_tests { . ': https://rt.cpan.org/Ticket/Display.html?id=64206' if $q; - foreach my $type (qw( blob clob )) { - foreach my $size (qw( small large )) { - $id++; + my $id; + foreach my $size (qw( small large )) { + $id++; - lives_ok { $rs->create( { 'id' => $id, $type => $binstr{$size} } ) } - "inserted $size $type without dying"; - ok($rs->find($id)->$type eq $binstr{$size}, "verified inserted $size $type" ); + my $str = $binstr{$size}; + lives_ok { + $rs->create( { 'id' => $id, blob => "blob:$str", clob => "clob:$str" } ) + } "inserted $size without dying"; + + my @objs = $rs->search({ blob => "blob:$str", clob => "clob:$str" })->all; + is (@objs, 1, 'One row found matching on both LOBs'); + ok (try { $objs[0]->blob }||'' eq "blob:$str", 'blob inserted/retrieved correctly'); + ok (try { $objs[0]->clob }||'' eq "clob:$str", 'clob inserted/retrieved correctly'); + + if ($size eq 'large') { # check that prepare_cached was NOT used + my $sql = ${ $rs->search({ blob => "blob:$str", clob => "clob:$str" }) + ->as_query }->[0]; + + ok((not exists $schema->storage->_dbh->{CachedKids}{$sql}), + 'multi-part LOB equality query was not cached'); } + + @objs = $rs->search({ clob => { -like => 'clob:%' } })->all; + ok (@objs, 'rows found matching CLOB with a LIKE query'); + + ok(my $subq = $rs->search({ blob => "blob:$str", clob => "clob:$str" }) + ->get_column('id')->as_query); + + @objs = $rs->search({ id => { -in => $subq } })->all; + is (@objs, 1, 'One row found matching on both LOBs as a subquery'); } $schema->storage->debug ($orig_debug);