1 package DBIx::Class::Storage::DBI::Sybase;
7 DBIx::Class::Storage::DBI::Sybase::Common
8 DBIx::Class::Storage::DBI::AutoCast
11 use Carp::Clan qw/^DBIx::Class/;
15 __PACKAGE__->mk_group_accessors('simple' =>
16 qw/_identity _blob_log_on_update _writer_storage _is_extra_storage
17 _bulk_storage _is_bulk_storage _began_bulk_work
18 _bulk_disabled_due_to_coderef_connect_info_warned
22 my @also_proxy_to_extra_storages = qw/
23 disconnect _connect_info _sql_maker _sql_maker_opts disable_sth_caching
24 auto_savepoint unsafe cursor_class debug debugobj schema
29 DBIx::Class::Storage::DBI::Sybase - Sybase support for DBIx::Class
33 This subclass supports L<DBD::Sybase> for real Sybase databases. If you are
34 using an MSSQL database via L<DBD::Sybase>, your storage will be reblessed to
35 L<DBIx::Class::Storage::DBI::Sybase::Microsoft_SQL_Server>.
39 If your version of Sybase does not support placeholders, then your storage
40 will be reblessed to L<DBIx::Class::Storage::DBI::Sybase::NoBindVars>. You can
41 also enable that driver explicitly, see the documentation for more details.
43 With this driver there is unfortunately no way to get the C<last_insert_id>
44 without doing a C<SELECT MAX(col)>. This is done safely in a transaction
45 (locking the table.) See L</INSERTS WITH PLACEHOLDERS>.
47 A recommended L<DBIx::Class::Storage::DBI/connect_info> setting:
49 on_connect_call => [['datetime_setup'], ['blob_setup', log_on_update => 0]]
58 if (ref($self) eq 'DBIx::Class::Storage::DBI::Sybase') {
60 @{$self->_get_dbh->selectrow_arrayref(qq{sp_server_info \@attribute_id=1})}[2]
65 my $subclass = "DBIx::Class::Storage::DBI::Sybase::${dbtype}";
67 if (!$exception && $dbtype && $self->load_optional_class($subclass)) {
68 bless $self, $subclass;
70 } else { # real Sybase
71 my $no_bind_vars = 'DBIx::Class::Storage::DBI::Sybase::NoBindVars';
73 if ($self->using_freetds) {
74 carp <<'EOF' unless $ENV{DBIC_SYBASE_FREETDS_NOWARN};
76 You are using FreeTDS with Sybase.
78 We will do our best to support this configuration, but please consider this
81 TEXT/IMAGE columns will definitely not work.
83 You are encouraged to recompile DBD::Sybase with the Sybase Open Client libraries
86 See perldoc DBIx::Class::Storage::DBI::Sybase for more details.
88 To turn off this warning set the DBIC_SYBASE_FREETDS_NOWARN environment
91 if (not $self->_typeless_placeholders_supported) {
92 if ($self->_placeholders_supported) {
95 $self->ensure_class_loaded($no_bind_vars);
96 bless $self, $no_bind_vars;
101 elsif (not $self->_get_dbh->{syb_dynamic_supported}) {
102 # not necessarily FreeTDS, but no placeholders nevertheless
103 $self->ensure_class_loaded($no_bind_vars);
104 bless $self, $no_bind_vars;
106 } elsif (not $self->_typeless_placeholders_supported) {
107 # this is highly unlikely, but we check just in case
116 $self->_set_max_connect(256);
118 # based on LongReadLen in connect_info
119 $self->set_textsize if $self->using_freetds;
121 # create storage for insert/(update blob) transactions,
122 # unless this is that storage
123 return if $self->_is_extra_storage;
125 my $writer_storage = (ref $self)->new;
127 $writer_storage->_is_extra_storage(1);
128 $writer_storage->connect_info($self->connect_info);
130 $self->_writer_storage($writer_storage);
132 # create a bulk storage unless connect_info is a coderef
134 if (Scalar::Util::reftype($self->_dbi_connect_info->[0])||'') eq 'CODE';
136 my $bulk_storage = (ref $self)->new;
138 $bulk_storage->_is_extra_storage(1);
139 $bulk_storage->_is_bulk_storage(1); # for special ->disconnect acrobatics
140 $bulk_storage->connect_info($self->connect_info);
143 $bulk_storage->_dbi_connect_info->[0] .= ';bulkLogin=1';
145 $self->_bulk_storage($bulk_storage);
148 for my $method (@also_proxy_to_extra_storages) {
150 no warnings 'redefine';
152 my $replaced = __PACKAGE__->can($method);
154 *{$method} = Sub::Name::subname $method => sub {
156 $self->_writer_storage->$replaced(@_) if $self->_writer_storage;
157 $self->_bulk_storage->$replaced(@_) if $self->_bulk_storage;
158 return $self->$replaced(@_);
165 # Even though we call $sth->finish for uses off the bulk API, there's still an
166 # "active statement" warning on disconnect, which we throw away here.
167 # This is due to the bug described in insert_bulk.
168 # Currently a noop because 'prepare' is used instead of 'prepare_cached'.
169 local $SIG{__WARN__} = sub {
170 warn $_[0] unless $_[0] =~ /active statement/i;
171 } if $self->_is_bulk_storage;
173 # so that next transaction gets a dbh
174 $self->_began_bulk_work(0) if $self->_is_bulk_storage;
179 # Make sure we have CHAINED mode turned on if AutoCommit is off in non-FreeTDS
180 # DBD::Sybase (since we don't know how DBD::Sybase was compiled.) If however
181 # we're using FreeTDS, CHAINED mode turns on an implicit transaction which we
182 # only want when AutoCommit is off.
186 $self->next::method(@_);
188 if ($self->_is_bulk_storage) {
189 # this should be cleared on every reconnect
190 $self->_began_bulk_work(0);
194 if (not $self->using_freetds) {
195 $self->_dbh->{syb_chained_txn} = 1;
197 if ($self->_dbh_autocommit) {
198 $self->_dbh->do('SET CHAINED OFF');
200 $self->_dbh->do('SET CHAINED ON');
205 =head2 connect_call_blob_setup
209 on_connect_call => [ [ 'blob_setup', log_on_update => 0 ] ]
211 Does C<< $dbh->{syb_binary_images} = 1; >> to return C<IMAGE> data as raw binary
212 instead of as a hex string.
216 Also sets the C<log_on_update> value for blob write operations. The default is
217 C<1>, but C<0> is better if your database is configured for it.
220 L<DBD::Sybase/Handling_IMAGE/TEXT_data_with_syb_ct_get_data()/syb_ct_send_data()>.
224 sub connect_call_blob_setup {
227 my $dbh = $self->_dbh;
228 $dbh->{syb_binary_images} = 1;
230 $self->_blob_log_on_update($args{log_on_update})
231 if exists $args{log_on_update};
237 $type && $type =~ /(?:text|image|lob|bytea|binary|memo)/i;
240 sub _prep_for_execute {
242 my ($op, $extra_bind, $ident, $args) = @_;
244 my ($sql, $bind) = $self->next::method (@_);
246 if ($op eq 'insert') {
247 my $table = $ident->from;
249 my $bind_info = $self->_resolve_column_info(
250 $ident, [map $_->[0], @{$bind}]
252 my $identity_col = List::Util::first
253 { $bind_info->{$_}{is_auto_increment} }
259 "SET IDENTITY_INSERT $table ON",
261 "SET IDENTITY_INSERT $table OFF",
265 $identity_col = List::Util::first
266 { $ident->column_info($_)->{is_auto_increment} }
274 $self->_fetch_identity_sql($ident, $identity_col);
278 return ($sql, $bind);
281 # Stolen from SQLT, with some modifications. This is a makeshift
282 # solution before a sane type-mapping library is available, thus
283 # the 'our' for easy overrides.
284 our %TYPE_MAPPING = (
287 varchar => 'varchar',
288 varchar2 => 'varchar',
289 timestamp => 'datetime',
291 real => 'double precision',
294 tinyint => 'smallint',
295 float => 'double precision',
297 bigserial => 'numeric',
298 boolean => 'varchar',
302 sub _native_data_type {
303 my ($self, $type) = @_;
306 $type =~ s/\s* identity//x;
308 return uc($TYPE_MAPPING{$type} || $type);
311 sub _fetch_identity_sql {
312 my ($self, $source, $col) = @_;
314 return sprintf ("SELECT MAX(%s) FROM %s",
315 map { $self->sql_maker->_quote ($_) } ($col, $source->from)
323 my ($rv, $sth, @bind) = $self->dbh_do($self->can('_dbh_execute'), @_);
325 if ($op eq 'insert') {
326 $self->_identity($sth->fetchrow_array);
330 return wantarray ? ($rv, $sth, @bind) : $rv;
333 sub last_insert_id { shift->_identity }
335 # handles TEXT/IMAGE and transaction for last_insert_id
338 my ($source, $to_insert) = @_;
340 my $blob_cols = $self->_remove_blob_cols($source, $to_insert);
342 my $identity_col = List::Util::first
343 { $source->column_info($_)->{is_auto_increment} }
346 # do we need the horrific SELECT MAX(COL) hack?
347 my $dumb_last_insert_id =
349 && (not exists $to_insert->{$identity_col})
350 && ($self->_identity_method||'') ne '@@IDENTITY';
352 my $next = $self->next::can;
354 # we are already in a transaction, or there are no blobs
355 # and we don't need the PK - just (try to) do it
356 if ($self->{transaction_depth}
357 || (!$blob_cols && !$dumb_last_insert_id)
359 return $self->_insert (
360 $next, $source, $to_insert, $blob_cols, $identity_col
364 # otherwise use the _writer_storage to do the insert+transaction on another
366 my $guard = $self->_writer_storage->txn_scope_guard;
368 my $updated_cols = $self->_writer_storage->_insert (
369 $next, $source, $to_insert, $blob_cols, $identity_col
372 $self->_identity($self->_writer_storage->_identity);
376 return $updated_cols;
380 my ($self, $next, $source, $to_insert, $blob_cols, $identity_col) = @_;
382 my $updated_cols = $self->$next ($source, $to_insert);
385 $identity_col => $self->last_insert_id($source, $identity_col),
390 $self->_insert_blobs ($source, $blob_cols, $final_row) if $blob_cols;
392 return $updated_cols;
397 my ($source, $fields, $where) = @_;
399 my $wantarray = wantarray;
400 my $blob_cols = $self->_remove_blob_cols($source, $fields);
402 if (not $blob_cols) {
403 return $self->next::method(@_);
406 # update+blob update(s) done atomically on separate connection
407 $self = $self->_writer_storage;
409 my $guard = $self->txn_scope_guard;
413 @res = $self->next::method(@_);
415 elsif (defined $wantarray) {
416 $res[0] = $self->next::method(@_);
419 $self->next::method(@_);
422 $self->_update_blobs($source, $blob_cols, $where);
426 return $wantarray ? @res : $res[0];
429 ### the insert_bulk partially stolen from DBI/MSSQL.pm
431 sub _set_identity_insert {
432 my ($self, $table) = @_;
435 'SET IDENTITY_INSERT %s ON',
436 $self->sql_maker->_quote ($table),
439 my $dbh = $self->_get_dbh;
440 eval { $dbh->do ($sql) };
442 $self->throw_exception (sprintf "Error executing '%s': %s",
449 sub _unset_identity_insert {
450 my ($self, $table) = @_;
453 'SET IDENTITY_INSERT %s OFF',
454 $self->sql_maker->_quote ($table),
457 my $dbh = $self->_get_dbh;
461 ## XXX add blob support
464 my ($source, $cols, $data) = @_;
466 my $is_identity_insert = (List::Util::first
467 { $source->column_info ($_)->{is_auto_increment} } @{$cols}
470 my @source_columns = $source->columns;
473 $self->_bulk_storage &&
474 $self->_get_dbh->{syb_has_blk};
476 if ((not $use_bulk_api) &&
477 (Scalar::Util::reftype($self->_dbi_connect_info->[0])||'') eq 'CODE' &&
478 (not $self->_bulk_disabled_due_to_coderef_connect_info_warned)) {
480 Bulk API support disabled due to use of a CODEREF connect_info. Reverting to
483 $self->_bulk_disabled_due_to_coderef_connect_info_warned(1);
486 if (not $use_bulk_api) {
487 if ($is_identity_insert) {
488 $self->_set_identity_insert ($source->name);
491 $self->next::method(@_);
493 if ($is_identity_insert) {
494 $self->_unset_identity_insert ($source->name);
500 # otherwise, use the bulk API
502 # rearrange @$data so that columns are in database order
504 @orig_idx{@$cols} = 0..$#$cols;
507 @new_idx{@source_columns} = 0..$#source_columns;
510 for my $datum (@$data) {
512 for my $col (@source_columns) {
513 # identity data will be 'undef' if not $is_identity_insert
514 # columns with defaults will also be 'undef'
515 $new_datum->[ $new_idx{$col} ] =
516 exists $orig_idx{$col} ? $datum->[ $orig_idx{$col} ] : undef;
518 push @new_data, $new_datum;
521 my $identity_col = List::Util::first
522 { $source->column_info($_)->{is_auto_increment} } @source_columns;
524 # bcp identity index is 1-based
525 my $identity_idx = exists $new_idx{$identity_col} ?
526 $new_idx{$identity_col} + 1 : 0;
528 ## Set a client-side conversion error handler, straight from DBD::Sybase docs.
529 # This ignores any data conversion errors detected by the client side libs, as
530 # they are usually harmless.
531 my $orig_cslib_cb = DBD::Sybase::set_cslib_cb(
532 Sub::Name::subname insert_bulk => sub {
533 my ($layer, $origin, $severity, $errno, $errmsg, $osmsg, $blkmsg) = @_;
535 return 1 if $errno == 36;
538 "Layer: $layer, Origin: $origin, Severity: $severity, Error: $errno" .
539 ($errmsg ? "\n$errmsg" : '') .
540 ($osmsg ? "\n$osmsg" : '') .
541 ($blkmsg ? "\n$blkmsg" : '');
547 my $bulk = $self->_bulk_storage;
549 my $guard = $bulk->txn_scope_guard;
551 ## XXX get this to work instead of our own $sth
552 ## will require SQLA or *Hacks changes for ordered columns
553 # $bulk->next::method($source, \@source_columns, \@new_data, {
554 # syb_bcp_attribs => {
555 # identity_flag => $is_identity_insert,
556 # identity_column => $identity_idx,
559 my $sql = 'INSERT INTO ' .
560 $bulk->sql_maker->_quote($source->name) . ' (' .
561 # colname list is ignored for BCP, but does no harm
562 (join ', ', map $bulk->sql_maker->_quote($_), @source_columns) . ') '.
563 ' VALUES ('. (join ', ', ('?') x @source_columns) . ')';
565 ## XXX there's a bug in the DBD::Sybase bulk support that makes $sth->finish for
566 ## a prepare_cached statement ineffective. Replace with ->sth when fixed, or
567 ## better yet the version above. Should be fixed in DBD::Sybase .
568 my $sth = $bulk->_get_dbh->prepare($sql,
572 identity_flag => $is_identity_insert,
573 identity_column => $identity_idx,
578 my $bind_attributes = $self->source_bind_attributes($source);
580 foreach my $slice_idx (0..$#source_columns) {
581 my $col = $source_columns[$slice_idx];
583 my $attributes = $bind_attributes->{$col}
584 if $bind_attributes && defined $bind_attributes->{$col};
586 my @slice = map $_->[$slice_idx], @new_data;
588 $sth->bind_param_array(($slice_idx + 1), \@slice, $attributes);
591 $bulk->_query_start($sql);
593 # this is stolen from DBI::insert_bulk
594 my $tuple_status = [];
595 my $rv = eval { $sth->execute_array({ArrayTupleStatus => $tuple_status}) };
597 if (my $err = $@ || $sth->errstr) {
599 ++$i while $i <= $#$tuple_status && !ref $tuple_status->[$i];
601 $self->throw_exception("Unexpected populate error: $err")
602 if ($i > $#$tuple_status);
604 require Data::Dumper;
605 local $Data::Dumper::Terse = 1;
606 local $Data::Dumper::Indent = 1;
607 local $Data::Dumper::Useqq = 1;
608 local $Data::Dumper::Quotekeys = 0;
609 local $Data::Dumper::Sortkeys = 1;
611 $self->throw_exception(sprintf "%s for populate slice:\n%s",
612 ($tuple_status->[$i][1] || $err),
613 Data::Dumper::Dumper(
614 { map { $source_columns[$_] => $new_data[$i][$_] } (0 .. $#$cols) }
622 $bulk->_query_end($sql);
625 if ($exception =~ /-Y option/) {
628 Sybase bulk API operation failed due to character set incompatibility, reverting
629 to regular array inserts:
631 *** Try unsetting the LANG environment variable.
635 $self->_bulk_storage(undef);
636 DBD::Sybase::set_cslib_cb($orig_cslib_cb);
641 DBD::Sybase::set_cslib_cb($orig_cslib_cb);
642 # rollback makes the bulkLogin connection unusable
643 $self->_bulk_storage->disconnect;
644 $self->throw_exception($exception);
647 DBD::Sybase::set_cslib_cb($orig_cslib_cb);
650 sub _remove_blob_cols {
651 my ($self, $source, $fields) = @_;
655 for my $col (keys %$fields) {
656 if ($self->_is_lob_type($source->column_info($col)->{data_type})) {
657 $blob_cols{$col} = delete $fields->{$col};
658 $fields->{$col} = \"''";
662 return keys %blob_cols ? \%blob_cols : undef;
666 my ($self, $source, $blob_cols, $where) = @_;
668 my (@primary_cols) = $source->primary_columns;
670 croak "Cannot update TEXT/IMAGE column(s) without a primary key"
671 unless @primary_cols;
673 # check if we're updating a single row by PK
674 my $pk_cols_in_where = 0;
675 for my $col (@primary_cols) {
676 $pk_cols_in_where++ if defined $where->{$col};
680 if ($pk_cols_in_where == @primary_cols) {
682 @row_to_update{@primary_cols} = @{$where}{@primary_cols};
683 @rows = \%row_to_update;
685 my $cursor = $self->select ($source, \@primary_cols, $where, {});
687 my %row; @row{@primary_cols} = @$_; \%row
691 for my $row (@rows) {
692 $self->_insert_blobs($source, $blob_cols, $row);
697 my ($self, $source, $blob_cols, $row) = @_;
698 my $dbh = $self->_get_dbh;
700 my $table = $source->from;
703 my (@primary_cols) = $source->primary_columns;
705 croak "Cannot update TEXT/IMAGE column(s) without a primary key"
706 unless @primary_cols;
708 if ((grep { defined $row{$_} } @primary_cols) != @primary_cols) {
709 croak "Cannot update TEXT/IMAGE column(s) without primary key values";
712 for my $col (keys %$blob_cols) {
713 my $blob = $blob_cols->{$col};
715 my %where = map { ($_, $row{$_}) } @primary_cols;
717 my $cursor = $self->select ($source, [$col], \%where, {});
719 my $sth = $cursor->sth;
723 $sth->func('CS_GET', 1, 'ct_data_info') or die $sth->errstr;
726 $sth->func('ct_prepare_send') or die $sth->errstr;
728 my $log_on_update = $self->_blob_log_on_update;
729 $log_on_update = 1 if not defined $log_on_update;
731 $sth->func('CS_SET', 1, {
732 total_txtlen => length($blob),
733 log_on_update => $log_on_update
734 }, 'ct_data_info') or die $sth->errstr;
736 $sth->func($blob, length($blob), 'ct_send_data') or die $sth->errstr;
738 $sth->func('ct_finish_send') or die $sth->errstr;
741 $sth->finish if $sth;
743 if ($self->using_freetds) {
745 'TEXT/IMAGE operation failed, probably because you are using FreeTDS: '
755 =head2 connect_call_datetime_setup
759 on_connect_call => 'datetime_setup'
761 In L<DBIx::Class::Storage::DBI/connect_info> to set:
763 $dbh->syb_date_fmt('ISO_strict'); # output fmt: 2004-08-21T14:36:48.080Z
764 $dbh->do('set dateformat mdy'); # input fmt: 08/13/1979 18:08:55.080
766 On connection for use with L<DBIx::Class::InflateColumn::DateTime>, using
767 L<DateTime::Format::Sybase>, which you will need to install.
769 This works for both C<DATETIME> and C<SMALLDATETIME> columns, although
770 C<SMALLDATETIME> columns only have minute precision.
775 my $old_dbd_warned = 0;
777 sub connect_call_datetime_setup {
779 my $dbh = $self->_dbh;
781 if ($dbh->can('syb_date_fmt')) {
782 # amazingly, this works with FreeTDS
783 $dbh->syb_date_fmt('ISO_strict');
784 } elsif (not $old_dbd_warned) {
785 carp "Your DBD::Sybase is too old to support ".
786 "DBIx::Class::InflateColumn::DateTime, please upgrade!";
790 $dbh->do('SET DATEFORMAT mdy');
796 sub datetime_parser_type { "DateTime::Format::Sybase" }
798 # ->begin_work and such have no effect with FreeTDS but we run them anyway to
799 # let the DBD keep any state it needs to.
801 # If they ever do start working, the extra statements will do no harm (because
802 # Sybase supports nested transactions.)
804 sub _dbh_begin_work {
807 # bulkLogin=1 connections are always in a transaction, and can only call BEGIN
808 # TRAN once. However, we need to make sure there's a $dbh.
809 return if $self->_is_bulk_storage && $self->_dbh && $self->_began_bulk_work;
811 $self->next::method(@_);
813 if ($self->using_freetds) {
814 $self->_get_dbh->do('BEGIN TRAN');
817 $self->_began_bulk_work(1) if $self->_is_bulk_storage;
822 if ($self->using_freetds) {
823 $self->_dbh->do('COMMIT');
825 return $self->next::method(@_);
830 if ($self->using_freetds) {
831 $self->_dbh->do('ROLLBACK');
833 return $self->next::method(@_);
836 # savepoint support using ASE syntax
839 my ($self, $name) = @_;
841 $self->_get_dbh->do("SAVE TRANSACTION $name");
844 # A new SAVE TRANSACTION with the same name releases the previous one.
845 sub _svp_release { 1 }
848 my ($self, $name) = @_;
850 $self->_get_dbh->do("ROLLBACK TRANSACTION $name");
855 =head1 Schema::Loader Support
857 There is an experimental branch of L<DBIx::Class::Schema::Loader> that will
858 allow you to dump a schema from most (if not all) versions of Sybase.
860 It is available via subversion from:
862 http://dev.catalyst.perl.org/repos/bast/branches/DBIx-Class-Schema-Loader/current/
866 This driver supports L<DBD::Sybase> compiled against FreeTDS
867 (L<http://www.freetds.org/>) to the best of our ability, however it is
868 recommended that you recompile L<DBD::Sybase> against the Sybase Open Client
869 libraries. They are a part of the Sybase ASE distribution:
871 The Open Client FAQ is here:
872 L<http://www.isug.com/Sybase_FAQ/ASE/section7.html>.
874 Sybase ASE for Linux (which comes with the Open Client libraries) may be
875 downloaded here: L<http://response.sybase.com/forms/ASE_Linux_Download>.
877 To see if you're using FreeTDS check C<< $schema->storage->using_freetds >>, or run:
879 perl -MDBI -le 'my $dbh = DBI->connect($dsn, $user, $pass); print $dbh->{syb_oc_version}'
881 Some versions of the libraries involved will not support placeholders, in which
882 case the storage will be reblessed to
883 L<DBIx::Class::Storage::DBI::Sybase::NoBindVars>.
885 In some configurations, placeholders will work but will throw implicit type
886 conversion errors for anything that's not expecting a string. In such a case,
887 the C<auto_cast> option from L<DBIx::Class::Storage::DBI::AutoCast> is
888 automatically set, which you may enable on connection with
889 L<DBIx::Class::Storage::DBI::AutoCast/connect_call_set_auto_cast>. The type info
890 for the C<CAST>s is taken from the L<DBIx::Class::ResultSource/data_type>
891 definitions in your Result classes, and are mapped to a Sybase type (if it isn't
892 already) using a mapping based on L<SQL::Translator>.
894 In other configurations, placeholers will work just as they do with the Sybase
895 Open Client libraries.
897 Inserts or updates of TEXT/IMAGE columns will B<NOT> work with FreeTDS.
899 =head1 INSERTS WITH PLACEHOLDERS
901 With placeholders enabled, inserts are done in a transaction so that there are
902 no concurrency issues with getting the inserted identity value using
903 C<SELECT MAX(col)>, which is the only way to get the C<IDENTITY> value in this
906 In addition, they are done on a separate connection so that it's possible to
907 have active cursors when doing an insert.
909 When using C<DBIx::Class::Storage::DBI::Sybase::NoBindVars> transactions are
910 disabled, as there are no concurrency issues with C<SELECT @@IDENTITY> as it's a
915 Due to limitations of the TDS protocol, L<DBD::Sybase>, or both; you cannot
916 begin a transaction while there are active cursors. An active cursor is, for
917 example, a L<ResultSet|DBIx::Class::ResultSet> that has been executed using
918 C<next> or C<first> but has not been exhausted or
919 L<reset|DBIx::Class::ResultSet/reset>.
921 For example, this will not work:
923 $schema->txn_do(sub {
924 my $rs = $schema->resultset('Book');
925 while (my $row = $rs->next) {
926 $schema->resultset('MetaData')->create({
933 Transactions done for inserts in C<AutoCommit> mode when placeholders are in use
934 are not affected, as they are done on an extra database handle.
940 =item * use L<DBIx::Class::Storage::DBI::Replicated>
942 =item * L<connect|DBIx::Class::Schema/connect> another L<Schema|DBIx::Class::Schema>
944 =item * load the data from your cursor with L<DBIx::Class::ResultSet/all>
948 =head1 MAXIMUM CONNECTIONS
950 The TDS protocol makes separate connections to the server for active statements
951 in the background. By default the number of such connections is limited to 25,
952 on both the client side and the server side.
954 This is a bit too low for a complex L<DBIx::Class> application, so on connection
955 the client side setting is set to C<256> (see L<DBD::Sybase/maxConnect>.) You
956 can override it to whatever setting you like in the DSN.
959 L<http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.help.ase_15.0.sag1/html/sag1/sag1272.htm>
960 for information on changing the setting on the server side.
964 See L</connect_call_datetime_setup> to setup date formats
965 for L<DBIx::Class::InflateColumn::DateTime>.
967 =head1 TEXT/IMAGE COLUMNS
969 L<DBD::Sybase> compiled with FreeTDS will B<NOT> allow you to insert or update
970 C<TEXT/IMAGE> columns.
972 Setting C<< $dbh->{LongReadLen} >> will also not work with FreeTDS use either:
974 $schema->storage->dbh->do("SET TEXTSIZE $bytes");
978 $schema->storage->set_textsize($bytes);
982 However, the C<LongReadLen> you pass in
983 L<DBIx::Class::Storage::DBI/connect_info> is used to execute the equivalent
984 C<SET TEXTSIZE> command on connection.
986 See L</connect_call_blob_setup> for a L<DBIx::Class::Storage::DBI/connect_info>
987 setting you need to work with C<IMAGE> columns.
991 The experimental L<DBD::Sybase> Bulk API support is used for
992 L<populate|DBIx::Class::ResultSet/populate> in B<void> context, in a transaction
993 on a separate connection.
995 To use this feature effectively, use a large number of rows for each
996 L<populate|DBIx::Class::ResultSet/populate> call, eg.:
998 while (my $rows = $data_source->get_100_rows()) {
999 $rs->populate($rows);
1002 B<NOTE:> the L<add_columns|DBIx::Class::ResultSource/add_columns>
1003 calls in your C<Result> classes B<must> list columns in database order for this
1004 to work. Also, you may have to unset the C<LANG> environment variable before
1005 loading your app, if it doesn't match the character set of your database.
1007 When inserting IMAGE columns using this method, you'll need to use
1008 L</connect_call_blob_setup> as well.
1012 See L<DBIx::Class/CONTRIBUTORS>.
1016 You may distribute this code under the same terms as Perl itself.