1 package DBIx::Class::Storage::DBI::Sybase::ASE;
7 DBIx::Class::Storage::DBI::Sybase
8 DBIx::Class::Storage::DBI::AutoCast
11 use DBIx::Class::Carp;
12 use Scalar::Util 'blessed';
13 use List::Util 'first';
15 use Data::Dumper::Concise 'Dumper';
19 __PACKAGE__->sql_limit_dialect ('RowCountOrGenericSubQ');
20 __PACKAGE__->sql_quote_char ([qw/[ ]/]);
21 __PACKAGE__->datetime_parser_type('DateTime::Format::Sybase');
23 __PACKAGE__->mk_group_accessors('simple' =>
24 qw/_identity _blob_log_on_update _writer_storage _is_extra_storage
25 _bulk_storage _is_bulk_storage _began_bulk_work
26 _bulk_disabled_due_to_coderef_connect_info_warned
30 my @also_proxy_to_extra_storages = qw/
31 connect_call_set_auto_cast auto_cast connect_call_blob_setup
32 connect_call_datetime_setup
34 disconnect _connect_info _sql_maker _sql_maker_opts disable_sth_caching
35 auto_savepoint unsafe cursor_class debug debugobj schema
40 DBIx::Class::Storage::DBI::Sybase::ASE - Sybase ASE SQL Server support for
45 This subclass supports L<DBD::Sybase> for real (non-Microsoft) Sybase databases.
49 If your version of Sybase does not support placeholders, then your storage will
50 be reblessed to L<DBIx::Class::Storage::DBI::Sybase::ASE::NoBindVars>.
51 You can also enable that driver explicitly, see the documentation for more
54 With this driver there is unfortunately no way to get the C<last_insert_id>
55 without doing a C<SELECT MAX(col)>. This is done safely in a transaction
56 (locking the table.) See L</INSERTS WITH PLACEHOLDERS>.
58 A recommended L<connect_info|DBIx::Class::Storage::DBI/connect_info> setting:
60 on_connect_call => [['datetime_setup'], ['blob_setup', log_on_update => 0]]
69 my $no_bind_vars = __PACKAGE__ . '::NoBindVars';
71 if ($self->using_freetds) {
72 carp <<'EOF' unless $ENV{DBIC_SYBASE_FREETDS_NOWARN};
74 You are using FreeTDS with Sybase.
76 We will do our best to support this configuration, but please consider this
79 TEXT/IMAGE columns will definitely not work.
81 You are encouraged to recompile DBD::Sybase with the Sybase Open Client libraries
84 See perldoc DBIx::Class::Storage::DBI::Sybase::ASE for more details.
86 To turn off this warning set the DBIC_SYBASE_FREETDS_NOWARN environment
90 if (not $self->_use_typeless_placeholders) {
91 if ($self->_use_placeholders) {
95 $self->ensure_class_loaded($no_bind_vars);
96 bless $self, $no_bind_vars;
102 elsif (not $self->_get_dbh->{syb_dynamic_supported}) {
103 # not necessarily FreeTDS, but no placeholders nevertheless
104 $self->ensure_class_loaded($no_bind_vars);
105 bless $self, $no_bind_vars;
108 # this is highly unlikely, but we check just in case
109 elsif (not $self->_use_typeless_placeholders) {
116 $self->_set_max_connect(256);
118 # create storage for insert/(update blob) transactions,
119 # unless this is that storage
120 return if $self->_is_extra_storage;
122 my $writer_storage = (ref $self)->new;
124 $writer_storage->_is_extra_storage(1);
125 $writer_storage->connect_info($self->connect_info);
126 $writer_storage->auto_cast($self->auto_cast);
128 $self->_writer_storage($writer_storage);
130 # create a bulk storage unless connect_info is a coderef
131 return if ref($self->_dbi_connect_info->[0]) eq 'CODE';
133 my $bulk_storage = (ref $self)->new;
135 $bulk_storage->_is_extra_storage(1);
136 $bulk_storage->_is_bulk_storage(1); # for special ->disconnect acrobatics
137 $bulk_storage->connect_info($self->connect_info);
140 $bulk_storage->_dbi_connect_info->[0] .= ';bulkLogin=1';
142 $self->_bulk_storage($bulk_storage);
145 for my $method (@also_proxy_to_extra_storages) {
147 no warnings 'redefine';
149 my $replaced = __PACKAGE__->can($method);
151 *{$method} = Sub::Name::subname $method => sub {
153 $self->_writer_storage->$replaced(@_) if $self->_writer_storage;
154 $self->_bulk_storage->$replaced(@_) if $self->_bulk_storage;
155 return $self->$replaced(@_);
162 # Even though we call $sth->finish for uses off the bulk API, there's still an
163 # "active statement" warning on disconnect, which we throw away here.
164 # This is due to the bug described in insert_bulk.
165 # Currently a noop because 'prepare' is used instead of 'prepare_cached'.
166 local $SIG{__WARN__} = sub {
167 warn $_[0] unless $_[0] =~ /active statement/i;
168 } if $self->_is_bulk_storage;
170 # so that next transaction gets a dbh
171 $self->_began_bulk_work(0) if $self->_is_bulk_storage;
176 # Set up session settings for Sybase databases for the connection.
178 # Make sure we have CHAINED mode turned on if AutoCommit is off in non-FreeTDS
179 # DBD::Sybase (since we don't know how DBD::Sybase was compiled.) If however
180 # we're using FreeTDS, CHAINED mode turns on an implicit transaction which we
181 # only want when AutoCommit is off.
183 # Also SET TEXTSIZE for FreeTDS because LongReadLen doesn't work.
184 sub _run_connection_actions {
187 if ($self->_is_bulk_storage) {
188 # this should be cleared on every reconnect
189 $self->_began_bulk_work(0);
193 if (not $self->using_freetds) {
194 $self->_dbh->{syb_chained_txn} = 1;
196 # based on LongReadLen in connect_info
199 if ($self->_dbh_autocommit) {
200 $self->_dbh->do('SET CHAINED OFF');
202 $self->_dbh->do('SET CHAINED ON');
206 $self->next::method(@_);
209 =head2 connect_call_blob_setup
213 on_connect_call => [ [ 'blob_setup', log_on_update => 0 ] ]
215 Does C<< $dbh->{syb_binary_images} = 1; >> to return C<IMAGE> data as raw binary
216 instead of as a hex string.
220 Also sets the C<log_on_update> value for blob write operations. The default is
221 C<1>, but C<0> is better if your database is configured for it.
224 L<DBD::Sybase/Handling_IMAGE/TEXT_data_with_syb_ct_get_data()/syb_ct_send_data()>.
228 sub connect_call_blob_setup {
231 my $dbh = $self->_dbh;
232 $dbh->{syb_binary_images} = 1;
234 $self->_blob_log_on_update($args{log_on_update})
235 if exists $args{log_on_update};
239 my ($self, $source, $column) = @_;
241 return $self->_is_lob_type($source->column_info($column)->{data_type});
244 sub _prep_for_execute {
246 my ($op, $ident, $args) = @_;
248 my ($sql, $bind) = $self->next::method (@_);
250 my $table = blessed $ident ? $ident->from : $ident;
252 my $bind_info = $self->_resolve_column_info(
253 $ident, [map { $_->[0]{dbic_colname} || () } @{$bind}]
255 my $bound_identity_col =
256 first { $bind_info->{$_}{is_auto_increment} }
260 my $columns_info = blessed $ident && $ident->columns_info;
264 first { $columns_info->{$_}{is_auto_increment} }
268 if (($op eq 'insert' && $bound_identity_col) ||
269 ($op eq 'update' && exists $args->[0]{$identity_col})) {
271 $self->_set_table_identity_sql($op => $table, 'on'),
273 $self->_set_table_identity_sql($op => $table, 'off'),
277 if ($op eq 'insert' && (not $bound_identity_col) && $identity_col &&
278 (not $self->{insert_bulk})) {
281 $self->_fetch_identity_sql($ident, $identity_col);
284 return ($sql, $bind);
287 sub _set_table_identity_sql {
288 my ($self, $op, $table, $on_off) = @_;
290 return sprintf 'SET IDENTITY_%s %s %s',
291 uc($op), $self->sql_maker->_quote($table), uc($on_off);
294 # Stolen from SQLT, with some modifications. This is a makeshift
295 # solution before a sane type-mapping library is available, thus
296 # the 'our' for easy overrides.
297 our %TYPE_MAPPING = (
300 varchar => 'varchar',
301 varchar2 => 'varchar',
302 timestamp => 'datetime',
304 real => 'double precision',
307 tinyint => 'smallint',
308 float => 'double precision',
310 bigserial => 'numeric',
311 boolean => 'varchar',
315 sub _native_data_type {
316 my ($self, $type) = @_;
319 $type =~ s/\s* identity//x;
321 return uc($TYPE_MAPPING{$type} || $type);
324 sub _fetch_identity_sql {
325 my ($self, $source, $col) = @_;
327 return sprintf ("SELECT MAX(%s) FROM %s",
328 map { $self->sql_maker->_quote ($_) } ($col, $source->from)
336 my ($rv, $sth, @bind) = $self->next::method(@_);
338 if ($op eq 'insert') {
339 $self->_identity($sth->fetchrow_array);
343 return wantarray ? ($rv, $sth, @bind) : $rv;
346 sub last_insert_id { shift->_identity }
348 # handles TEXT/IMAGE and transaction for last_insert_id
351 my ($source, $to_insert) = @_;
353 my $columns_info = $source->columns_info;
356 (first { $columns_info->{$_}{is_auto_increment} }
357 keys %$columns_info )
360 # check for empty insert
361 # INSERT INTO foo DEFAULT VALUES -- does not work with Sybase
362 # try to insert explicit 'DEFAULT's instead (except for identity, timestamp
363 # and computed columns)
364 if (not %$to_insert) {
365 for my $col ($source->columns) {
366 next if $col eq $identity_col;
368 my $info = $source->column_info($col);
370 next if ref $info->{default_value} eq 'SCALAR'
371 || (exists $info->{data_type} && (not defined $info->{data_type}));
373 next if $info->{data_type} && $info->{data_type} =~ /^timestamp\z/i;
375 $to_insert->{$col} = \'DEFAULT';
379 my $blob_cols = $self->_remove_blob_cols($source, $to_insert);
381 # do we need the horrific SELECT MAX(COL) hack?
382 my $dumb_last_insert_id =
384 && (not exists $to_insert->{$identity_col})
385 && ($self->_identity_method||'') ne '@@IDENTITY';
387 my $next = $self->next::can;
389 # we are already in a transaction, or there are no blobs
390 # and we don't need the PK - just (try to) do it
391 if ($self->{transaction_depth}
392 || (!$blob_cols && !$dumb_last_insert_id)
394 return $self->_insert (
395 $next, $source, $to_insert, $blob_cols, $identity_col
399 # otherwise use the _writer_storage to do the insert+transaction on another
401 my $guard = $self->_writer_storage->txn_scope_guard;
403 my $updated_cols = $self->_writer_storage->_insert (
404 $next, $source, $to_insert, $blob_cols, $identity_col
407 $self->_identity($self->_writer_storage->_identity);
411 return $updated_cols;
415 my ($self, $next, $source, $to_insert, $blob_cols, $identity_col) = @_;
417 my $updated_cols = $self->$next ($source, $to_insert);
421 ($identity_col => $self->last_insert_id($source, $identity_col)) : ()),
426 $self->_insert_blobs ($source, $blob_cols, $final_row) if $blob_cols;
428 return $updated_cols;
433 my ($source, $fields, $where, @rest) = @_;
435 my $blob_cols = $self->_remove_blob_cols($source, $fields);
437 my $table = $source->name;
439 my $columns_info = $source->columns_info;
442 first { $columns_info->{$_}{is_auto_increment} }
445 my $is_identity_update = $identity_col && defined $fields->{$identity_col};
447 return $self->next::method(@_) unless $blob_cols;
449 # If there are any blobs in $where, Sybase will return a descriptive error
451 # XXX blobs can still be used with a LIKE query, and this should be handled.
453 # update+blob update(s) done atomically on separate connection
454 $self = $self->_writer_storage;
456 my $guard = $self->txn_scope_guard;
458 # First update the blob columns to be updated to '' (taken from $fields, where
459 # it is originally put by _remove_blob_cols .)
460 my %blobs_to_empty = map { ($_ => delete $fields->{$_}) } keys %$blob_cols;
462 # We can't only update NULL blobs, because blobs cannot be in the WHERE clause.
464 $self->next::method($source, \%blobs_to_empty, $where, @rest);
466 # Now update the blobs before the other columns in case the update of other
467 # columns makes the search condition invalid.
468 $self->_update_blobs($source, $blob_cols, $where);
473 @res = $self->next::method(@_);
475 elsif (defined wantarray) {
476 $res[0] = $self->next::method(@_);
479 $self->next::method(@_);
485 return wantarray ? @res : $res[0];
490 my ($source, $cols, $data) = @_;
492 my $columns_info = $source->columns_info;
495 first { $columns_info->{$_}{is_auto_increment} }
498 my $is_identity_insert = (first { $_ eq $identity_col } @{$cols}) ? 1 : 0;
500 my @source_columns = $source->columns;
503 $self->_bulk_storage &&
504 $self->_get_dbh->{syb_has_blk};
506 if ((not $use_bulk_api)
508 (ref($self->_dbi_connect_info->[0]) eq 'CODE')
510 (not $self->_bulk_disabled_due_to_coderef_connect_info_warned)) {
512 Bulk API support disabled due to use of a CODEREF connect_info. Reverting to
513 regular array inserts.
515 $self->_bulk_disabled_due_to_coderef_connect_info_warned(1);
518 if (not $use_bulk_api) {
519 my $blob_cols = $self->_remove_blob_cols_array($source, $cols, $data);
521 # _execute_array uses a txn anyway, but it ends too early in case we need to
522 # select max(col) to get the identity for inserting blobs.
523 ($self, my $guard) = $self->{transaction_depth} == 0 ?
524 ($self->_writer_storage, $self->_writer_storage->txn_scope_guard)
528 local $self->{insert_bulk} = 1;
530 $self->next::method(@_);
533 if ($is_identity_insert) {
534 $self->_insert_blobs_array ($source, $blob_cols, $cols, $data);
537 my @cols_with_identities = (@$cols, $identity_col);
539 ## calculate identities
540 # XXX This assumes identities always increase by 1, which may or may not
542 my ($last_identity) =
543 $self->_dbh->selectrow_array (
544 $self->_fetch_identity_sql($source, $identity_col)
546 my @identities = (($last_identity - @$data + 1) .. $last_identity);
548 my @data_with_identities = map [@$_, shift @identities], @$data;
550 $self->_insert_blobs_array (
551 $source, $blob_cols, \@cols_with_identities, \@data_with_identities
556 $guard->commit if $guard;
561 # otherwise, use the bulk API
563 # rearrange @$data so that columns are in database order
565 @orig_idx{@$cols} = 0..$#$cols;
568 @new_idx{@source_columns} = 0..$#source_columns;
571 for my $datum (@$data) {
573 for my $col (@source_columns) {
574 # identity data will be 'undef' if not $is_identity_insert
575 # columns with defaults will also be 'undef'
576 $new_datum->[ $new_idx{$col} ] =
577 exists $orig_idx{$col} ? $datum->[ $orig_idx{$col} ] : undef;
579 push @new_data, $new_datum;
582 # bcp identity index is 1-based
583 my $identity_idx = exists $new_idx{$identity_col} ?
584 $new_idx{$identity_col} + 1 : 0;
586 ## Set a client-side conversion error handler, straight from DBD::Sybase docs.
587 # This ignores any data conversion errors detected by the client side libs, as
588 # they are usually harmless.
589 my $orig_cslib_cb = DBD::Sybase::set_cslib_cb(
590 Sub::Name::subname insert_bulk => sub {
591 my ($layer, $origin, $severity, $errno, $errmsg, $osmsg, $blkmsg) = @_;
593 return 1 if $errno == 36;
596 "Layer: $layer, Origin: $origin, Severity: $severity, Error: $errno" .
597 ($errmsg ? "\n$errmsg" : '') .
598 ($osmsg ? "\n$osmsg" : '') .
599 ($blkmsg ? "\n$blkmsg" : '');
606 my $bulk = $self->_bulk_storage;
608 my $guard = $bulk->txn_scope_guard;
610 ## XXX get this to work instead of our own $sth
611 ## will require SQLA or *Hacks changes for ordered columns
612 # $bulk->next::method($source, \@source_columns, \@new_data, {
613 # syb_bcp_attribs => {
614 # identity_flag => $is_identity_insert,
615 # identity_column => $identity_idx,
618 my $sql = 'INSERT INTO ' .
619 $bulk->sql_maker->_quote($source->name) . ' (' .
620 # colname list is ignored for BCP, but does no harm
621 (join ', ', map $bulk->sql_maker->_quote($_), @source_columns) . ') '.
622 ' VALUES ('. (join ', ', ('?') x @source_columns) . ')';
624 ## XXX there's a bug in the DBD::Sybase bulk support that makes $sth->finish for
625 ## a prepare_cached statement ineffective. Replace with ->sth when fixed, or
626 ## better yet the version above. Should be fixed in DBD::Sybase .
627 my $sth = $bulk->_get_dbh->prepare($sql,
631 identity_flag => $is_identity_insert,
632 identity_column => $identity_idx,
637 my @bind = map { [ $source_columns[$_] => $_ ] } (0 .. $#source_columns);
639 $self->_execute_array(
640 $source, $sth, \@bind, \@source_columns, \@new_data, sub {
645 $bulk->_query_end($sql);
650 DBD::Sybase::set_cslib_cb($orig_cslib_cb);
652 if ($exception =~ /-Y option/) {
653 my $w = 'Sybase bulk API operation failed due to character set incompatibility, '
654 . 'reverting to regular array inserts. Try unsetting the LANG environment variable'
656 $w .= "\n$exception" if $self->debug;
659 $self->_bulk_storage(undef);
664 # rollback makes the bulkLogin connection unusable
665 $self->_bulk_storage->disconnect;
666 $self->throw_exception($exception);
670 sub _dbh_execute_array {
671 my ($self, $sth, $tuple_status, $cb) = @_;
673 my $rv = $self->next::method($sth, $tuple_status);
679 # Make sure blobs are not bound as placeholders, and return any non-empty ones
681 sub _remove_blob_cols {
682 my ($self, $source, $fields) = @_;
686 for my $col (keys %$fields) {
687 if ($self->_is_lob_column($source, $col)) {
688 my $blob_val = delete $fields->{$col};
689 if (not defined $blob_val) {
690 $fields->{$col} = \'NULL';
693 $fields->{$col} = \"''";
694 $blob_cols{$col} = $blob_val unless $blob_val eq '';
699 return %blob_cols ? \%blob_cols : undef;
702 # same for insert_bulk
703 sub _remove_blob_cols_array {
704 my ($self, $source, $cols, $data) = @_;
708 for my $i (0..$#$cols) {
709 my $col = $cols->[$i];
711 if ($self->_is_lob_column($source, $col)) {
712 for my $j (0..$#$data) {
713 my $blob_val = delete $data->[$j][$i];
714 if (not defined $blob_val) {
715 $data->[$j][$i] = \'NULL';
718 $data->[$j][$i] = \"''";
719 $blob_cols[$j][$i] = $blob_val
720 unless $blob_val eq '';
726 return @blob_cols ? \@blob_cols : undef;
730 my ($self, $source, $blob_cols, $where) = @_;
732 my @primary_cols = try
733 { $source->_pri_cols }
735 $self->throw_exception("Cannot update TEXT/IMAGE column(s): $_")
738 # check if we're updating a single row by PK
739 my $pk_cols_in_where = 0;
740 for my $col (@primary_cols) {
741 $pk_cols_in_where++ if defined $where->{$col};
745 if ($pk_cols_in_where == @primary_cols) {
747 @row_to_update{@primary_cols} = @{$where}{@primary_cols};
748 @rows = \%row_to_update;
750 my $cursor = $self->select ($source, \@primary_cols, $where, {});
752 my %row; @row{@primary_cols} = @$_; \%row
756 for my $row (@rows) {
757 $self->_insert_blobs($source, $blob_cols, $row);
762 my ($self, $source, $blob_cols, $row) = @_;
763 my $dbh = $self->_get_dbh;
765 my $table = $source->name;
768 my @primary_cols = try
769 { $source->_pri_cols }
771 $self->throw_exception("Cannot update TEXT/IMAGE column(s): $_")
774 $self->throw_exception('Cannot update TEXT/IMAGE column(s) without primary key values')
775 if ((grep { defined $row{$_} } @primary_cols) != @primary_cols);
777 for my $col (keys %$blob_cols) {
778 my $blob = $blob_cols->{$col};
780 my %where = map { ($_, $row{$_}) } @primary_cols;
782 my $cursor = $self->select ($source, [$col], \%where, {});
784 my $sth = $cursor->sth;
787 $self->throw_exception(
788 "Could not find row in table '$table' for blob update:\n"
795 $sth->func('CS_GET', 1, 'ct_data_info') or die $sth->errstr;
798 $sth->func('ct_prepare_send') or die $sth->errstr;
800 my $log_on_update = $self->_blob_log_on_update;
801 $log_on_update = 1 if not defined $log_on_update;
803 $sth->func('CS_SET', 1, {
804 total_txtlen => length($blob),
805 log_on_update => $log_on_update
806 }, 'ct_data_info') or die $sth->errstr;
808 $sth->func($blob, length($blob), 'ct_send_data') or die $sth->errstr;
810 $sth->func('ct_finish_send') or die $sth->errstr;
813 if ($self->using_freetds) {
814 $self->throw_exception (
815 "TEXT/IMAGE operation failed, probably because you are using FreeTDS: $_"
819 $self->throw_exception($_);
823 $sth->finish if $sth;
828 sub _insert_blobs_array {
829 my ($self, $source, $blob_cols, $cols, $data) = @_;
831 for my $i (0..$#$data) {
832 my $datum = $data->[$i];
835 @row{ @$cols } = @$datum;
838 for my $j (0..$#$cols) {
839 if (exists $blob_cols->[$i][$j]) {
840 $blob_vals{ $cols->[$j] } = $blob_cols->[$i][$j];
844 $self->_insert_blobs ($source, \%blob_vals, \%row);
848 =head2 connect_call_datetime_setup
852 on_connect_call => 'datetime_setup'
854 In L<connect_info|DBIx::Class::Storage::DBI/connect_info> to set:
856 $dbh->syb_date_fmt('ISO_strict'); # output fmt: 2004-08-21T14:36:48.080Z
857 $dbh->do('set dateformat mdy'); # input fmt: 08/13/1979 18:08:55.080
859 On connection for use with L<DBIx::Class::InflateColumn::DateTime>, using
860 L<DateTime::Format::Sybase>, which you will need to install.
862 This works for both C<DATETIME> and C<SMALLDATETIME> columns, although
863 C<SMALLDATETIME> columns only have minute precision.
867 sub connect_call_datetime_setup {
869 my $dbh = $self->_get_dbh;
871 if ($dbh->can('syb_date_fmt')) {
872 # amazingly, this works with FreeTDS
873 $dbh->syb_date_fmt('ISO_strict');
877 'Your DBD::Sybase is too old to support '
878 .'DBIx::Class::InflateColumn::DateTime, please upgrade!';
880 $dbh->do('SET DATEFORMAT mdy');
886 # ->begin_work and such have no effect with FreeTDS but we run them anyway to
887 # let the DBD keep any state it needs to.
889 # If they ever do start working, the extra statements will do no harm (because
890 # Sybase supports nested transactions.)
892 sub _dbh_begin_work {
895 # bulkLogin=1 connections are always in a transaction, and can only call BEGIN
896 # TRAN once. However, we need to make sure there's a $dbh.
897 return if $self->_is_bulk_storage && $self->_dbh && $self->_began_bulk_work;
899 $self->next::method(@_);
901 if ($self->using_freetds) {
902 $self->_get_dbh->do('BEGIN TRAN');
905 $self->_began_bulk_work(1) if $self->_is_bulk_storage;
910 if ($self->using_freetds) {
911 $self->_dbh->do('COMMIT');
913 return $self->next::method(@_);
918 if ($self->using_freetds) {
919 $self->_dbh->do('ROLLBACK');
921 return $self->next::method(@_);
924 # savepoint support using ASE syntax
927 my ($self, $name) = @_;
929 $self->_get_dbh->do("SAVE TRANSACTION $name");
932 # A new SAVE TRANSACTION with the same name releases the previous one.
933 sub _svp_release { 1 }
936 my ($self, $name) = @_;
938 $self->_get_dbh->do("ROLLBACK TRANSACTION $name");
943 =head1 Schema::Loader Support
945 As of version C<0.05000>, L<DBIx::Class::Schema::Loader> should work well with
946 most (if not all) versions of Sybase ASE.
950 This driver supports L<DBD::Sybase> compiled against FreeTDS
951 (L<http://www.freetds.org/>) to the best of our ability, however it is
952 recommended that you recompile L<DBD::Sybase> against the Sybase Open Client
953 libraries. They are a part of the Sybase ASE distribution:
955 The Open Client FAQ is here:
956 L<http://www.isug.com/Sybase_FAQ/ASE/section7.html>.
958 Sybase ASE for Linux (which comes with the Open Client libraries) may be
959 downloaded here: L<http://response.sybase.com/forms/ASE_Linux_Download>.
961 To see if you're using FreeTDS check C<< $schema->storage->using_freetds >>, or run:
963 perl -MDBI -le 'my $dbh = DBI->connect($dsn, $user, $pass); print $dbh->{syb_oc_version}'
965 Some versions of the libraries involved will not support placeholders, in which
966 case the storage will be reblessed to
967 L<DBIx::Class::Storage::DBI::Sybase::ASE::NoBindVars>.
969 In some configurations, placeholders will work but will throw implicit type
970 conversion errors for anything that's not expecting a string. In such a case,
971 the C<auto_cast> option from L<DBIx::Class::Storage::DBI::AutoCast> is
972 automatically set, which you may enable on connection with
973 L<DBIx::Class::Storage::DBI::AutoCast/connect_call_set_auto_cast>. The type info
974 for the C<CAST>s is taken from the L<DBIx::Class::ResultSource/data_type>
975 definitions in your Result classes, and are mapped to a Sybase type (if it isn't
976 already) using a mapping based on L<SQL::Translator>.
978 In other configurations, placeholders will work just as they do with the Sybase
979 Open Client libraries.
981 Inserts or updates of TEXT/IMAGE columns will B<NOT> work with FreeTDS.
983 =head1 INSERTS WITH PLACEHOLDERS
985 With placeholders enabled, inserts are done in a transaction so that there are
986 no concurrency issues with getting the inserted identity value using
987 C<SELECT MAX(col)>, which is the only way to get the C<IDENTITY> value in this
990 In addition, they are done on a separate connection so that it's possible to
991 have active cursors when doing an insert.
993 When using C<DBIx::Class::Storage::DBI::Sybase::ASE::NoBindVars> transactions
994 are disabled, as there are no concurrency issues with C<SELECT @@IDENTITY> as
995 it's a session variable.
999 Due to limitations of the TDS protocol, L<DBD::Sybase>, or both, you cannot
1000 begin a transaction while there are active cursors, nor can you use multiple
1001 active cursors within a transaction. An active cursor is, for example, a
1002 L<ResultSet|DBIx::Class::ResultSet> that has been executed using C<next> or
1003 C<first> but has not been exhausted or L<reset|DBIx::Class::ResultSet/reset>.
1005 For example, this will not work:
1007 $schema->txn_do(sub {
1008 my $rs = $schema->resultset('Book');
1009 while (my $row = $rs->next) {
1010 $schema->resultset('MetaData')->create({
1011 book_id => $row->id,
1019 my $first_row = $large_rs->first;
1020 $schema->txn_do(sub { ... });
1022 Transactions done for inserts in C<AutoCommit> mode when placeholders are in use
1023 are not affected, as they are done on an extra database handle.
1029 =item * use L<DBIx::Class::Storage::DBI::Replicated>
1031 =item * L<connect|DBIx::Class::Schema/connect> another L<Schema|DBIx::Class::Schema>
1033 =item * load the data from your cursor with L<DBIx::Class::ResultSet/all>
1037 =head1 MAXIMUM CONNECTIONS
1039 The TDS protocol makes separate connections to the server for active statements
1040 in the background. By default the number of such connections is limited to 25,
1041 on both the client side and the server side.
1043 This is a bit too low for a complex L<DBIx::Class> application, so on connection
1044 the client side setting is set to C<256> (see L<DBD::Sybase/maxConnect>.) You
1045 can override it to whatever setting you like in the DSN.
1048 L<http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.help.ase_15.0.sag1/html/sag1/sag1272.htm>
1049 for information on changing the setting on the server side.
1053 See L</connect_call_datetime_setup> to setup date formats
1054 for L<DBIx::Class::InflateColumn::DateTime>.
1056 =head1 TEXT/IMAGE COLUMNS
1058 L<DBD::Sybase> compiled with FreeTDS will B<NOT> allow you to insert or update
1059 C<TEXT/IMAGE> columns.
1061 Setting C<< $dbh->{LongReadLen} >> will also not work with FreeTDS use either:
1063 $schema->storage->dbh->do("SET TEXTSIZE $bytes");
1067 $schema->storage->set_textsize($bytes);
1071 However, the C<LongReadLen> you pass in
1072 L<connect_info|DBIx::Class::Storage::DBI/connect_info> is used to execute the
1073 equivalent C<SET TEXTSIZE> command on connection.
1075 See L</connect_call_blob_setup> for a
1076 L<connect_info|DBIx::Class::Storage::DBI/connect_info> setting you need to work
1077 with C<IMAGE> columns.
1081 The experimental L<DBD::Sybase> Bulk API support is used for
1082 L<populate|DBIx::Class::ResultSet/populate> in B<void> context, in a transaction
1083 on a separate connection.
1085 To use this feature effectively, use a large number of rows for each
1086 L<populate|DBIx::Class::ResultSet/populate> call, eg.:
1088 while (my $rows = $data_source->get_100_rows()) {
1089 $rs->populate($rows);
1092 B<NOTE:> the L<add_columns|DBIx::Class::ResultSource/add_columns>
1093 calls in your C<Result> classes B<must> list columns in database order for this
1094 to work. Also, you may have to unset the C<LANG> environment variable before
1095 loading your app, if it doesn't match the character set of your database.
1097 When inserting IMAGE columns using this method, you'll need to use
1098 L</connect_call_blob_setup> as well.
1100 =head1 COMPUTED COLUMNS
1102 If you have columns such as:
1104 created_dtm AS getdate()
1106 represent them in your Result classes as:
1110 default_value => \'getdate()',
1114 The C<data_type> must exist and must be C<undef>. Then empty inserts will work
1115 on tables with such columns.
1117 =head1 TIMESTAMP COLUMNS
1119 C<timestamp> columns in Sybase ASE are not really timestamps, see:
1120 L<http://dba.fyicenter.com/Interview-Questions/SYBASE/The_timestamp_datatype_in_Sybase_.html>.
1122 They should be defined in your Result classes as:
1125 data_type => 'timestamp',
1127 inflate_datetime => 0,
1130 The C<<inflate_datetime => 0>> is necessary if you use
1131 L<DBIx::Class::InflateColumn::DateTime>, and most people do, and still want to
1132 be able to read these values.
1134 The values will come back as hexadecimal.
1142 Transitions to AutoCommit=0 (starting a transaction) mode by exhausting
1143 any active cursors, using eager cursors.
1147 Real limits and limited counts using stored procedures deployed on startup.
1151 Adaptive Server Anywhere (ASA) support
1155 Blob update with a LIKE query on a blob, without invalidating the WHERE condition.
1159 bulk_insert using prepare_cached (see comments.)
1165 See L<DBIx::Class/AUTHOR> and L<DBIx::Class/CONTRIBUTORS>.
1169 You may distribute this code under the same terms as Perl itself.