use warnings;
use base qw/
- DBIx::Class::Storage::DBI::Sybase::Base
- DBIx::Class::Storage::DBI
+ DBIx::Class::Storage::DBI::Sybase::Common
+ DBIx::Class::Storage::DBI::AutoCast
/;
use mro 'c3';
use Carp::Clan qw/^DBIx::Class/;
+use List::Util ();
+use Sub::Name ();
+
+__PACKAGE__->mk_group_accessors('simple' =>
+ qw/_identity _blob_log_on_update _writer_storage _is_writer_storage
+ _identity_method/
+);
+
+my @also_proxy_to_writer_storage = qw/
+ connect_call_set_auto_cast auto_cast connect_call_blob_setup
+ connect_call_datetime_setup
+
+ disconnect _connect_info _sql_maker _sql_maker_opts disable_sth_caching
+ auto_savepoint unsafe cursor_class debug debugobj schema
+/;
=head1 NAME
-DBIx::Class::Storage::DBI::Sybase - Storage::DBI subclass for Sybase
+DBIx::Class::Storage::DBI::Sybase - Sybase support for DBIx::Class
=head1 SYNOPSIS
also enable that driver explicitly, see the documentation for more details.
With this driver there is unfortunately no way to get the C<last_insert_id>
-without doing a C<select max(col)>.
-
-But your queries will be cached.
+without doing a C<SELECT MAX(col)>. This is done safely in a transaction
+(locking the table.) See L</INSERTS WITH PLACEHOLDERS>.
-You need a version of L<DBD::Sybase> compiled with the Sybase OpenClient
-libraries, B<NOT> FreeTDS, for placeholder support. Otherwise your storage will
-be automatically reblessed into C<::NoBindVars>.
+A recommended L<DBIx::Class::Storage::DBI/connect_info> setting:
-A recommended L<DBIx::Class::Storage::DBI/connect_info> settings:
-
- on_connect_call => [['datetime_setup'], [blob_setup => log_on_update => 0]]
+ on_connect_call => [['datetime_setup'], ['blob_setup', log_on_update => 0]]
=head1 METHODS
=cut
-__PACKAGE__->mk_group_accessors('simple' =>
- qw/_blob_log_on_update/
-);
-
sub _rebless {
my $self = shift;
if (ref($self) eq 'DBIx::Class::Storage::DBI::Sybase') {
my $dbtype = eval {
- @{$self->dbh->selectrow_arrayref(qq{sp_server_info \@attribute_id=1})}[2]
+ @{$self->_get_dbh->selectrow_arrayref(qq{sp_server_info \@attribute_id=1})}[2]
} || '';
my $exception = $@;
} else { # real Sybase
my $no_bind_vars = 'DBIx::Class::Storage::DBI::Sybase::NoBindVars';
- if (not $self->dbh->{syb_dynamic_supported}) {
- $self->ensure_class_loaded($no_bind_vars);
- bless $self, $no_bind_vars;
- $self->_rebless;
- }
-
- if ($self->_using_freetds) {
- carp <<'EOF';
+ if ($self->using_freetds) {
+ carp <<'EOF' unless $ENV{DBIC_SYBASE_FREETDS_NOWARN};
-Your version of Sybase potentially supports placeholders and query caching,
-however you seem to be using FreeTDS which does not (yet?) support this.
+You are using FreeTDS with Sybase.
-Please recompile DBD::Sybase with the Sybase OpenClient libraries if you want
-these features.
+We will do our best to support this configuration, but please consider this
+support experimental.
-TEXT/IMAGE column support will also not work under FreeTDS.
+TEXT/IMAGE columns will definitely not work.
+
+You are encouraged to recompile DBD::Sybase with the Sybase Open Client libraries
+instead.
See perldoc DBIx::Class::Storage::DBI::Sybase for more details.
+
+To turn off this warning set the DBIC_SYBASE_FREETDS_NOWARN environment
+variable.
EOF
+ if (not $self->_typeless_placeholders_supported) {
+ if ($self->_placeholders_supported) {
+ $self->auto_cast(1);
+ } else {
+ $self->ensure_class_loaded($no_bind_vars);
+ bless $self, $no_bind_vars;
+ $self->_rebless;
+ }
+ }
+ }
+ elsif (not $self->_get_dbh->{syb_dynamic_supported}) {
+ # not necessarily FreeTDS, but no placeholders nevertheless
$self->ensure_class_loaded($no_bind_vars);
bless $self, $no_bind_vars;
$self->_rebless;
+ } elsif (not $self->_typeless_placeholders_supported) {
+# this is highly unlikely, but we check just in case
+ $self->auto_cast(1);
}
- $self->_set_maxConnect;
}
}
}
-{
- my $using_freetds = undef;
+sub _init {
+ my $self = shift;
+ $self->_set_max_connect(256);
- sub _using_freetds {
- my $self = shift;
- my $dbh = $self->_dbh;
+ # based on LongReadLen in connect_info
+ $self->set_textsize if $self->using_freetds;
- return $using_freetds if defined $using_freetds;
+# create storage for insert/(update blob) transactions,
+# unless this is that storage
+ return if $self->_is_writer_storage;
- local $dbh->{syb_rowcount} = 1; # this is broken in freetds
- $using_freetds = @{ $dbh->selectall_arrayref('sp_help') } != 1;
+ my $writer_storage = (ref $self)->new;
- return $using_freetds;
- }
+ $writer_storage->_is_writer_storage(1);
+ $writer_storage->connect_info($self->connect_info);
+ $writer_storage->auto_cast($self->auto_cast);
+
+ $self->_writer_storage($writer_storage);
}
-sub _set_maxConnect {
- my $self = shift;
+for my $method (@also_proxy_to_writer_storage) {
+ no strict 'refs';
+ no warnings 'redefine';
- my $dsn = $self->_dbi_connect_info->[0];
+ my $replaced = __PACKAGE__->can($method);
- return if ref($dsn) eq 'CODE';
+ *{$method} = Sub::Name::subname __PACKAGE__."::$method" => sub {
+ my $self = shift;
+ $self->_writer_storage->$replaced(@_) if $self->_writer_storage;
+ return $self->$replaced(@_);
+ };
+}
- if ($dsn !~ /maxConnect=/) {
- $self->_dbi_connect_info->[0] = "$dsn;maxConnect=256";
- my $connected = defined $self->_dbh;
- $self->disconnect;
- $self->ensure_connected if $connected;
+# Make sure we have CHAINED mode turned on if AutoCommit is off in non-FreeTDS
+# DBD::Sybase (since we don't know how DBD::Sybase was compiled.) If however
+# we're using FreeTDS, CHAINED mode turns on an implicit transaction which we
+# only want when AutoCommit is off.
+sub _populate_dbh {
+ my $self = shift;
+
+ $self->next::method(@_);
+
+ if (not $self->using_freetds) {
+ $self->_dbh->{syb_chained_txn} = 1;
+ } else {
+ if ($self->_dbh_autocommit) {
+ $self->_dbh->do('SET CHAINED OFF');
+ } else {
+ $self->_dbh->do('SET CHAINED ON');
+ }
}
}
Used as:
- on_connect_call => [ [ blob_setup => log_on_update => 0 ] ]
+ on_connect_call => [ [ 'blob_setup', log_on_update => 0 ] ]
Does C<< $dbh->{syb_binary_images} = 1; >> to return C<IMAGE> data as raw binary
instead of as a hex string.
$type && $type =~ /(?:text|image|lob|bytea|binary|memo)/i;
}
-## This will be useful if we ever implement BLOB filehandle inflation and will
-## need to use the API, but for now it isn't.
-#
-#sub order_columns_for_select {
-# my ($self, $source) = @_;
-#
-# my (@non_blobs, @blobs);
-#
-# for my $col ($source->columns) {
-# if ($self->_is_lob_type($source->column_info($col)->{data_type})) {
-# push @blobs, $col;
-# } else {
-# push @non_blobs, $col;
-# }
-# }
-#
-# croak "cannot select more than a one TEXT/IMAGE column at a time"
-# if @blobs > 1;
-#
-# return (@non_blobs, @blobs);
-#}
+sub _is_lob_column {
+ my ($self, $source, $column) = @_;
+
+ return $self->_is_lob_type($source->column_info($column)->{data_type});
+}
+
+sub _prep_for_execute {
+ my $self = shift;
+ my ($op, $extra_bind, $ident, $args) = @_;
+
+ my ($sql, $bind) = $self->next::method (@_);
+
+ if ($op eq 'insert') {
+ my $table = $ident->from;
+
+ my $bind_info = $self->_resolve_column_info(
+ $ident, [map $_->[0], @{$bind}]
+ );
+ my $identity_col = List::Util::first
+ { $bind_info->{$_}{is_auto_increment} }
+ (keys %$bind_info)
+ ;
+
+ if ($identity_col) {
+ $sql = join ("\n",
+ "SET IDENTITY_INSERT $table ON",
+ $sql,
+ "SET IDENTITY_INSERT $table OFF",
+ );
+ }
+ else {
+ $identity_col = List::Util::first
+ { $ident->column_info($_)->{is_auto_increment} }
+ $ident->columns
+ ;
+ }
+
+ if ($identity_col) {
+ $sql =
+ "$sql\n" .
+ $self->_fetch_identity_sql($ident, $identity_col);
+ }
+ }
-# override to handle TEXT/IMAGE
+ return ($sql, $bind);
+}
+
+# Stolen from SQLT, with some modifications. This is a makeshift
+# solution before a sane type-mapping library is available, thus
+# the 'our' for easy overrides.
+our %TYPE_MAPPING = (
+ number => 'numeric',
+ money => 'money',
+ varchar => 'varchar',
+ varchar2 => 'varchar',
+ timestamp => 'datetime',
+ text => 'varchar',
+ real => 'double precision',
+ comment => 'text',
+ bit => 'bit',
+ tinyint => 'smallint',
+ float => 'double precision',
+ serial => 'numeric',
+ bigserial => 'numeric',
+ boolean => 'varchar',
+ long => 'varchar',
+);
+
+sub _native_data_type {
+ my ($self, $type) = @_;
+
+ $type = lc $type;
+ $type =~ s/\s* identity//x;
+
+ return uc($TYPE_MAPPING{$type} || $type);
+}
+
+sub _fetch_identity_sql {
+ my ($self, $source, $col) = @_;
+
+ return sprintf ("SELECT MAX(%s) FROM %s",
+ map { $self->sql_maker->_quote ($_) } ($col, $source->from)
+ );
+}
+
+sub _execute {
+ my $self = shift;
+ my ($op) = @_;
+
+ my ($rv, $sth, @bind) = $self->dbh_do($self->can('_dbh_execute'), @_);
+
+ if ($op eq 'insert') {
+ $self->_identity($sth->fetchrow_array);
+ $sth->finish;
+ }
+
+ return wantarray ? ($rv, $sth, @bind) : $rv;
+}
+
+sub last_insert_id { shift->_identity }
+
+# handles TEXT/IMAGE and transaction for last_insert_id
sub insert {
- my ($self, $source, $to_insert) = splice @_, 0, 3;
+ my $self = shift;
+ my ($source, $to_insert) = @_;
my $blob_cols = $self->_remove_blob_cols($source, $to_insert);
- my $updated_cols = $self->next::method($source, $to_insert, @_);
+ my $identity_col = List::Util::first
+ { $source->column_info($_)->{is_auto_increment} }
+ $source->columns;
+
+ # do we need the horrific SELECT MAX(COL) hack?
+ my $dumb_last_insert_id =
+ $identity_col
+ && (not exists $to_insert->{$identity_col})
+ && ($self->_identity_method||'') ne '@@IDENTITY';
+
+ my $next = $self->next::can;
+
+ # we are already in a transaction, or there are no blobs
+ # and we don't need the PK - just (try to) do it
+ if ($self->{transaction_depth}
+ || (!$blob_cols && !$dumb_last_insert_id)
+ ) {
+ return $self->_insert (
+ $next, $source, $to_insert, $blob_cols, $identity_col
+ );
+ }
+
+ # otherwise use the _writer_storage to do the insert+transaction on another
+ # connection
+ my $guard = $self->_writer_storage->txn_scope_guard;
+
+ my $updated_cols = $self->_writer_storage->_insert (
+ $next, $source, $to_insert, $blob_cols, $identity_col
+ );
- $self->_insert_blobs($source, $blob_cols, $to_insert) if %$blob_cols;
+ $self->_identity($self->_writer_storage->_identity);
+
+ $guard->commit;
+
+ return $updated_cols;
+}
+
+sub _insert {
+ my ($self, $next, $source, $to_insert, $blob_cols, $identity_col) = @_;
+
+ my $updated_cols = $self->$next ($source, $to_insert);
+
+ my $final_row = {
+ $identity_col => $self->last_insert_id($source, $identity_col),
+ %$to_insert,
+ %$updated_cols,
+ };
+
+ $self->_insert_blobs ($source, $blob_cols, $final_row) if $blob_cols;
return $updated_cols;
}
sub update {
- my ($self, $source) = splice @_, 0, 2;
- my ($fields, $where) = @_;
- my $wantarray = wantarray;
+ my $self = shift;
+ my ($source, $fields, $where, @rest) = @_;
+
+ my $wantarray = wantarray;
my $blob_cols = $self->_remove_blob_cols($source, $fields);
+ my $table = $source->name;
+
+ my $identity_col = List::Util::first
+ { $source->column_info($_)->{is_auto_increment} }
+ $source->columns;
+
+ my $is_identity_update = $identity_col && defined $fields->{$identity_col};
+
+ if (not $blob_cols) {
+ $self->_set_identity_insert($table, 'update') if $is_identity_update;
+ return $self->next::method(@_);
+ $self->_unset_identity_insert($table, 'update') if $is_identity_update;
+ }
+
+# check that we're not updating a blob column that's also in $where
+ for my $blob (grep $self->_is_lob_column($source, $_), $source->columns) {
+ if (exists $where->{$blob} && exists $fields->{$blob}) {
+ croak
+'Update of TEXT/IMAGE column that is also in search condition impossible';
+ }
+ }
+
+# update+blob update(s) done atomically on separate connection
+ $self = $self->_writer_storage;
+
+ my $guard = $self->txn_scope_guard;
+
+# First update the blob columns to be updated to '' (taken from $fields, where
+# it is originally put by _remove_blob_cols .)
+ my %blobs_to_empty = map { ($_ => delete $fields->{$_}) } keys %$blob_cols;
+
+ $self->next::method($source, \%blobs_to_empty, $where, @rest);
+
+# Now update the blobs before the other columns in case the update of other
+# columns makes the search condition invalid.
+ $self->_update_blobs($source, $blob_cols, $where);
+
my @res;
- if ($wantarray) {
- @res = $self->next::method($source, @_);
- } else {
- $res[0] = $self->next::method($source, @_);
+ if (%$fields) {
+ $self->_set_identity_insert($table, 'update') if $is_identity_update;
+
+ if ($wantarray) {
+ @res = $self->next::method(@_);
+ }
+ elsif (defined $wantarray) {
+ $res[0] = $self->next::method(@_);
+ }
+ else {
+ $self->next::method(@_);
+ }
+
+ $self->_unset_identity_insert($table, 'update') if $is_identity_update;
}
- $self->_update_blobs($source, $blob_cols, $where) if %$blob_cols;
+ $guard->commit;
return $wantarray ? @res : $res[0];
}
+### the insert_bulk stuff stolen from DBI/MSSQL.pm
+
+sub _set_identity_insert {
+ my ($self, $table, $op) = @_;
+
+ my $sql = sprintf (
+ 'SET IDENTITY_%s %s ON',
+ (uc($op) || 'INSERT'),
+ $self->sql_maker->_quote ($table),
+ );
+
+ $self->_query_start($sql);
+
+ my $dbh = $self->_get_dbh;
+ eval { $dbh->do ($sql) };
+ my $exception = $@;
+
+ $self->_query_end($sql);
+
+ if ($exception) {
+ $self->throw_exception (sprintf "Error executing '%s': %s",
+ $sql,
+ $dbh->errstr,
+ );
+ }
+}
+
+sub _unset_identity_insert {
+ my ($self, $table, $op) = @_;
+
+ my $sql = sprintf (
+ 'SET IDENTITY_%s %s OFF',
+ (uc($op) || 'INSERT'),
+ $self->sql_maker->_quote ($table),
+ );
+
+ $self->_query_start($sql);
+
+ my $dbh = $self->_get_dbh;
+ $dbh->do ($sql);
+
+ $self->_query_end($sql);
+}
+
+# for tests
+sub _can_insert_bulk { 1 }
+
+# XXX this should use the DBD::Sybase bulk API, where possible
+sub insert_bulk {
+ my $self = shift;
+ my ($source, $cols, $data) = @_;
+
+ my $is_identity_insert = (List::Util::first
+ { $source->column_info ($_)->{is_auto_increment} }
+ (@{$cols})
+ )
+ ? 1
+ : 0;
+
+ if ($is_identity_insert) {
+ $self->_set_identity_insert ($source->name);
+ }
+
+ $self->next::method(@_);
+
+ if ($is_identity_insert) {
+ $self->_unset_identity_insert ($source->name);
+ }
+}
+
+### end of stolen insert_bulk section
+
+# Make sure blobs are not bound as placeholders, and return any non-empty ones
+# as a hash.
sub _remove_blob_cols {
my ($self, $source, $fields) = @_;
for my $col (keys %$fields) {
if ($self->_is_lob_type($source->column_info($col)->{data_type})) {
- $blob_cols{$col} = delete $fields->{$col};
- $fields->{$col} = \"''";
+ my $blob_val = delete $fields->{$col};
+ if (not defined $blob_val) {
+ $fields->{$col} = \'NULL';
+ }
+ else {
+ $fields->{$col} = \"''";
+ $blob_cols{$col} = $blob_val unless $blob_val eq '';
+ }
}
}
- return \%blob_cols;
+ return keys %blob_cols ? \%blob_cols : undef;
}
sub _update_blobs {
my (@primary_cols) = $source->primary_columns;
- croak "Cannot update TEXT/IMAGE column(s) without a primary key"
+ $self->throw_exception('Cannot update TEXT/IMAGE column(s) without a primary key')
unless @primary_cols;
# check if we're updating a single row by PK
@row_to_update{@primary_cols} = @{$where}{@primary_cols};
@rows = \%row_to_update;
} else {
- my $rs = $source->resultset->search(
- $where,
- {
- result_class => 'DBIx::Class::ResultClass::HashRefInflator',
- select => \@primary_cols
- }
- );
- @rows = $rs->all; # statement must finish
+ my $cursor = $self->select ($source, \@primary_cols, $where, {});
+ @rows = map {
+ my %row; @row{@primary_cols} = @$_; \%row
+ } $cursor->all;
}
for my $row (@rows) {
sub _insert_blobs {
my ($self, $source, $blob_cols, $row) = @_;
- my $dbh = $self->dbh;
+ my $dbh = $self->_get_dbh;
- my $table = $source->from;
+ my $table = $source->name;
my %row = %$row;
my (@primary_cols) = $source->primary_columns;
- croak "Cannot update TEXT/IMAGE column(s) without a primary key"
+ $self->throw_exception('Cannot update TEXT/IMAGE column(s) without a primary key')
unless @primary_cols;
- if ((grep { defined $row{$_} } @primary_cols) != @primary_cols) {
- if (@primary_cols == 1) {
- my $col = $primary_cols[0];
- $row{$col} = $self->last_insert_id($source, $col);
- } else {
- croak "Cannot update TEXT/IMAGE column(s) without primary key values";
- }
- }
+ $self->throw_exception('Cannot update TEXT/IMAGE column(s) without primary key values')
+ if ((grep { defined $row{$_} } @primary_cols) != @primary_cols);
for my $col (keys %$blob_cols) {
my $blob = $blob_cols->{$col};
- my $sth;
- if (not $self->isa('DBIx::Class::Storage::DBI::NoBindVars')) {
- my $search_cond = join ',' => map "$_ = ?", @primary_cols;
+ my %where = map { ($_, $row{$_}) } @primary_cols;
- $sth = $self->sth(
- "select $col from $table where $search_cond"
- );
- $sth->execute(map $row{$_}, @primary_cols);
- } else {
- my $search_cond = join ',' => map "$_ = $row{$_}", @primary_cols;
+ my $cursor = $self->select ($source, [$col], \%where, {});
+ $cursor->next;
+ my $sth = $cursor->sth;
+
+ if (not $sth) {
- $sth = $dbh->prepare(
- "select $col from $table where $search_cond"
+ $self->throw_exception(
+ "Could not find row in table '$table' for blob update:\n"
+ . $self->_pretty_print (\%where)
);
- $sth->execute;
}
eval {
- while ($sth->fetch) {
+ do {
$sth->func('CS_GET', 1, 'ct_data_info') or die $sth->errstr;
- }
+ } while $sth->fetch;
+
$sth->func('ct_prepare_send') or die $sth->errstr;
my $log_on_update = $self->_blob_log_on_update;
$sth->func('ct_finish_send') or die $sth->errstr;
};
my $exception = $@;
- $sth->finish;
- croak $exception if $exception;
+ $sth->finish if $sth;
+ if ($exception) {
+ if ($self->using_freetds) {
+ $self->throw_exception (
+ 'TEXT/IMAGE operation failed, probably because you are using FreeTDS: '
+ . $exception
+ );
+ } else {
+ $self->throw_exception($exception);
+ }
+ }
}
}
my $dbh = $self->_dbh;
if ($dbh->can('syb_date_fmt')) {
+ # amazingly, this works with FreeTDS
$dbh->syb_date_fmt('ISO_strict');
} elsif (not $old_dbd_warned) {
carp "Your DBD::Sybase is too old to support ".
$old_dbd_warned = 1;
}
- $dbh->do('set dateformat mdy');
+ $dbh->do('SET DATEFORMAT mdy');
1;
}
sub datetime_parser_type { "DateTime::Format::Sybase" }
-sub _dbh_last_insert_id {
- my ($self, $dbh, $source, $col) = @_;
+# ->begin_work and such have no effect with FreeTDS but we run them anyway to
+# let the DBD keep any state it needs to.
+#
+# If they ever do start working, the extra statements will do no harm (because
+# Sybase supports nested transactions.)
+
+sub _dbh_begin_work {
+ my $self = shift;
+ $self->next::method(@_);
+ if ($self->using_freetds) {
+ $self->_get_dbh->do('BEGIN TRAN');
+ }
+}
+
+sub _dbh_commit {
+ my $self = shift;
+ if ($self->using_freetds) {
+ $self->_dbh->do('COMMIT');
+ }
+ return $self->next::method(@_);
+}
- # sorry, there's no other way!
- my $sth = $self->sth("select max($col) from ".$source->from);
- my ($id) = $dbh->selectrow_array($sth);
- $sth->finish;
+sub _dbh_rollback {
+ my $self = shift;
+ if ($self->using_freetds) {
+ $self->_dbh->do('ROLLBACK');
+ }
+ return $self->next::method(@_);
+}
+
+# savepoint support using ASE syntax
+
+sub _svp_begin {
+ my ($self, $name) = @_;
- return $id;
+ $self->_get_dbh->do("SAVE TRANSACTION $name");
+}
+
+# A new SAVE TRANSACTION with the same name releases the previous one.
+sub _svp_release { 1 }
+
+sub _svp_rollback {
+ my ($self, $name) = @_;
+
+ $self->_get_dbh->do("ROLLBACK TRANSACTION $name");
}
1;
+=head1 Schema::Loader Support
+
+There is an experimental branch of L<DBIx::Class::Schema::Loader> that will
+allow you to dump a schema from most (if not all) versions of Sybase.
+
+It is available via subversion from:
+
+ http://dev.catalyst.perl.org/repos/bast/branches/DBIx-Class-Schema-Loader/current/
+
+=head1 FreeTDS
+
+This driver supports L<DBD::Sybase> compiled against FreeTDS
+(L<http://www.freetds.org/>) to the best of our ability, however it is
+recommended that you recompile L<DBD::Sybase> against the Sybase Open Client
+libraries. They are a part of the Sybase ASE distribution:
+
+The Open Client FAQ is here:
+L<http://www.isug.com/Sybase_FAQ/ASE/section7.html>.
+
+Sybase ASE for Linux (which comes with the Open Client libraries) may be
+downloaded here: L<http://response.sybase.com/forms/ASE_Linux_Download>.
+
+To see if you're using FreeTDS check C<< $schema->storage->using_freetds >>, or run:
+
+ perl -MDBI -le 'my $dbh = DBI->connect($dsn, $user, $pass); print $dbh->{syb_oc_version}'
+
+Some versions of the libraries involved will not support placeholders, in which
+case the storage will be reblessed to
+L<DBIx::Class::Storage::DBI::Sybase::NoBindVars>.
+
+In some configurations, placeholders will work but will throw implicit type
+conversion errors for anything that's not expecting a string. In such a case,
+the C<auto_cast> option from L<DBIx::Class::Storage::DBI::AutoCast> is
+automatically set, which you may enable on connection with
+L<DBIx::Class::Storage::DBI::AutoCast/connect_call_set_auto_cast>. The type info
+for the C<CAST>s is taken from the L<DBIx::Class::ResultSource/data_type>
+definitions in your Result classes, and are mapped to a Sybase type (if it isn't
+already) using a mapping based on L<SQL::Translator>.
+
+In other configurations, placeholers will work just as they do with the Sybase
+Open Client libraries.
+
+Inserts or updates of TEXT/IMAGE columns will B<NOT> work with FreeTDS.
+
+=head1 INSERTS WITH PLACEHOLDERS
+
+With placeholders enabled, inserts are done in a transaction so that there are
+no concurrency issues with getting the inserted identity value using
+C<SELECT MAX(col)>, which is the only way to get the C<IDENTITY> value in this
+mode.
+
+In addition, they are done on a separate connection so that it's possible to
+have active cursors when doing an insert.
+
+When using C<DBIx::Class::Storage::DBI::Sybase::NoBindVars> transactions are
+disabled, as there are no concurrency issues with C<SELECT @@IDENTITY> as it's a
+session variable.
+
+=head1 TRANSACTIONS
+
+Due to limitations of the TDS protocol, L<DBD::Sybase>, or both; you cannot
+begin a transaction while there are active cursors. An active cursor is, for
+example, a L<ResultSet|DBIx::Class::ResultSet> that has been executed using
+C<next> or C<first> but has not been exhausted or
+L<reset|DBIx::Class::ResultSet/reset>.
+
+For example, this will not work:
+
+ $schema->txn_do(sub {
+ my $rs = $schema->resultset('Book');
+ while (my $row = $rs->next) {
+ $schema->resultset('MetaData')->create({
+ book_id => $row->id,
+ ...
+ });
+ }
+ });
+
+Transactions done for inserts in C<AutoCommit> mode when placeholders are in use
+are not affected, as they are done on an extra database handle.
+
+Some workarounds:
+
+=over 4
+
+=item * use L<DBIx::Class::Storage::DBI::Replicated>
+
+=item * L<connect|DBIx::Class::Schema/connect> another L<Schema|DBIx::Class::Schema>
+
+=item * load the data from your cursor with L<DBIx::Class::ResultSet/all>
+
+=back
+
=head1 MAXIMUM CONNECTIONS
-L<DBD::Sybase> makes separate connections to the server for active statements in
-the background. By default the number of such connections is limited to 25, on
-both the client side and the server side.
+The TDS protocol makes separate connections to the server for active statements
+in the background. By default the number of such connections is limited to 25,
+on both the client side and the server side.
-This is a bit too low, so on connection the clientside setting is set to C<256>
-(see L<DBD::Sybase/maxConnect>.) You can override it to whatever setting you
-like in the DSN.
+This is a bit too low for a complex L<DBIx::Class> application, so on connection
+the client side setting is set to C<256> (see L<DBD::Sybase/maxConnect>.) You
+can override it to whatever setting you like in the DSN.
See
L<http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.help.ase_15.0.sag1/html/sag1/sag1272.htm>
See L</connect_call_datetime_setup> to setup date formats
for L<DBIx::Class::InflateColumn::DateTime>.
-=head1 IMAGE AND TEXT COLUMNS
+=head1 TEXT/IMAGE COLUMNS
+
+L<DBD::Sybase> compiled with FreeTDS will B<NOT> allow you to insert or update
+C<TEXT/IMAGE> columns.
+
+Setting C<< $dbh->{LongReadLen} >> will also not work with FreeTDS use either:
+
+ $schema->storage->dbh->do("SET TEXTSIZE $bytes");
+
+or
+
+ $schema->storage->set_textsize($bytes);
+
+instead.
-L<DBD::Sybase> compiled with FreeTDS will B<NOT> work with C<TEXT/IMAGE>
-columns.
+However, the C<LongReadLen> you pass in
+L<DBIx::Class::Storage::DBI/connect_info> is used to execute the equivalent
+C<SET TEXTSIZE> command on connection.
See L</connect_call_blob_setup> for a L<DBIx::Class::Storage::DBI/connect_info>
setting you need to work with C<IMAGE> columns.
-=head1 AUTHORS
+=head1 AUTHOR
See L<DBIx::Class/CONTRIBUTORS>.
projects / dbsrgits/DBIx-Class.git / blobdiff