X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FSybase.pm;h=9072b38696fdb2adead8647088c287f33f88e5c6;hb=ddcc02d14d03169c54c65db9f0f446836483ba55;hp=1bb8956f99d0ec6c5c67de7cf3063cb7c58d4c4e;hpb=0a4b8fe0bec137ad4158b5e984cdd38c3e02a50a;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBI/Sybase.pm b/lib/DBIx/Class/Storage/DBI/Sybase.pm
index 1bb8956..9072b38 100644
--- a/lib/DBIx/Class/Storage/DBI/Sybase.pm
+++ b/lib/DBIx/Class/Storage/DBI/Sybase.pm
@@ -2,783 +2,146 @@ package DBIx::Class::Storage::DBI::Sybase;
 
 use strict;
 use warnings;
+use DBIx::Class::_Util 'dbic_internal_try';
+use Try::Tiny;
+use namespace::clean;
 
-use base qw/
-    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/
-  disconnect _connect_info _sql_maker _sql_maker_opts disable_sth_caching
-  auto_savepoint unsafe cursor_class debug debugobj schema
-/;
+use base qw/DBIx::Class::Storage::DBI/;
 
 =head1 NAME
 
-DBIx::Class::Storage::DBI::Sybase - Sybase support for DBIx::Class
-
-=head1 SYNOPSIS
-
-This subclass supports L<DBD::Sybase> for real Sybase databases.  If you are
-using an MSSQL database via L<DBD::Sybase>, your storage will be reblessed to
-L<DBIx::Class::Storage::DBI::Sybase::Microsoft_SQL_Server>.
+DBIx::Class::Storage::DBI::Sybase - Base class for drivers using
+L<DBD::Sybase>
 
 =head1 DESCRIPTION
 
-If your version of Sybase does not support placeholders, then your storage
-will be reblessed to L<DBIx::Class::Storage::DBI::Sybase::NoBindVars>. You can
-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)>. This is done safely in a transaction
-(locking the table.) See L</INSERTS WITH PLACEHOLDERS>.
-
-A recommended L<DBIx::Class::Storage::DBI/connect_info> setting:
-
-  on_connect_call => [['datetime_setup'], ['blob_setup', log_on_update => 0]]
+This is the base class/dispatcher for Storage's designed to work with
+L<DBD::Sybase>
 
 =head1 METHODS
 
 =cut
 
-sub _rebless {
-  my $self = shift;
-
-  if (ref($self) eq 'DBIx::Class::Storage::DBI::Sybase') {
-    my $dbtype = eval {
-      @{$self->_get_dbh->selectrow_arrayref(qq{sp_server_info \@attribute_id=1})}[2]
-    } || '';
-
-    my $exception = $@;
-    $dbtype =~ s/\W/_/gi;
-    my $subclass = "DBIx::Class::Storage::DBI::Sybase::${dbtype}";
-
-    if (!$exception && $dbtype && $self->load_optional_class($subclass)) {
-      bless $self, $subclass;
-      $self->_rebless;
-    } else { # real Sybase
-      my $no_bind_vars = 'DBIx::Class::Storage::DBI::Sybase::NoBindVars';
-
-      if ($self->using_freetds) {
-        carp <<'EOF' unless $ENV{DBIC_SYBASE_FREETDS_NOWARN};
-
-You are using FreeTDS with Sybase.
-
-We will do our best to support this configuration, but please consider this
-support experimental.
-
-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);
-      }
-    }
-  }
-}
+sub _rebless { shift->_determine_connector_driver('Sybase') }
 
-sub _init {
+sub _get_rdbms_name {
   my $self = shift;
-  $self->_set_max_connect(256);
 
-  # based on LongReadLen in connect_info
-  $self->set_textsize if $self->using_freetds;
+  dbic_internal_try {
+    my $name = $self->_get_dbh->selectrow_arrayref('sp_server_info @attribute_id=1')->[2];
 
-# create storage for insert/(update blob) transactions,
-# unless this is that storage
-  return if $self->_is_writer_storage;
+    if ($name) {
+      $name =~ s/\W/_/gi;
 
-  my $writer_storage = (ref $self)->new;
-
-  $writer_storage->_is_writer_storage(1);
-  $writer_storage->connect_info($self->connect_info);
-
-  $self->_writer_storage($writer_storage);
-}
-
-for my $method (@also_proxy_to_writer_storage) {
-  no strict 'refs';
-
-  my $replaced = __PACKAGE__->can($method);
+      # saner class name
+      $name = 'ASE' if $name eq 'SQL_Server';
+    }
 
-  *{$method} = Sub::Name::subname __PACKAGE__."::$method" => sub {
-    my $self = shift;
-    $self->_writer_storage->$replaced(@_) if $self->_writer_storage;
-    return $self->$replaced(@_);
+    $name;  # RV
+  } catch {
+    $self->throw_exception("Unable to establish connection to determine database type: $_")
   };
 }
 
-# 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 {
+sub _init {
+  # once the driver is determined see if we need to insert the DBD::Sybase w/ FreeTDS fixups
+  # this is a dirty version of "instance role application", \o/ DO WANT Moo \o/
   my $self = shift;
+  if (! $self->isa('DBIx::Class::Storage::DBI::Sybase::FreeTDS') and $self->_using_freetds) {
+    require DBIx::Class::Storage::DBI::Sybase::FreeTDS;
 
-  $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');
-    }
-  }
-}
-
-=head2 connect_call_blob_setup
-
-Used as:
-
-  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.
+    my @isa = @{mro::get_linear_isa(ref $self)};
+    my $class = shift @isa; # this is our current ref
 
-Recommended.
+    my $trait_class = $class . '::FreeTDS';
+    mro::set_mro ($trait_class, 'c3');
+    no strict 'refs';
+    @{"${trait_class}::ISA"} = ($class, 'DBIx::Class::Storage::DBI::Sybase::FreeTDS', @isa);
 
-Also sets the C<log_on_update> value for blob write operations. The default is
-C<1>, but C<0> is better if your database is configured for it.
+    bless ($self, $trait_class);
 
-See
-L<DBD::Sybase/Handling_IMAGE/TEXT_data_with_syb_ct_get_data()/syb_ct_send_data()>.
+    Class::C3->reinitialize() if DBIx::Class::_ENV_::OLD_MRO;
 
-=cut
-
-sub connect_call_blob_setup {
-  my $self = shift;
-  my %args = @_;
-  my $dbh = $self->_dbh;
-  $dbh->{syb_binary_images} = 1;
-
-  $self->_blob_log_on_update($args{log_on_update})
-    if exists $args{log_on_update};
-}
-
-sub _is_lob_type {
-  my $self = shift;
-  my $type = shift;
-  $type && $type =~ /(?:text|image|lob|bytea|binary|memo)/i;
-}
-
-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);
-    }
+    $self->_init(@_);
   }
 
-  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)
-  );
+  $self->next::method(@_);
 }
 
-sub _execute {
+sub _ping {
   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;
-}
+  my $dbh = $self->_dbh or return 0;
 
-sub last_insert_id { shift->_identity }
+  local $dbh->{RaiseError} = 1;
+  local $dbh->{PrintError} = 0;
 
-# handles TEXT/IMAGE and transaction for last_insert_id
-sub insert {
-  my $self = shift;
-  my ($source, $to_insert) = @_;
-
-  my $blob_cols = $self->_remove_blob_cols($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, $identity_col
-    );
+# FIXME if the main connection goes stale, does opening another for this statement
+# really determine anything?
+# FIXME (2) THIS MAKES 0 SENSE!!! Need to test later
+  if ($dbh->{syb_no_child_con}) {
+    return dbic_internal_try {
+      $self->_connect->do('select 1');
+      1;
+    }
+    catch {
+      0;
+    };
   }
 
-  # 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
+  return (
+    (dbic_internal_try {
+      $dbh->do('select 1');
+      1;
+    })
+      ? 1
+      : 0
   );
-
-  $self->_identity($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 {
+sub _set_max_connect {
   my $self = shift;
-  my ($source, $fields, $where) = @_;
+  my $val  = shift || 256;
 
-  my $wantarray = wantarray;
-  my $blob_cols = $self->_remove_blob_cols($source, $fields);
+  my $dsn = $self->_dbi_connect_info->[0];
 
-  if (not $blob_cols) {
-    return $self->next::method(@_);
-  }
+  return if ref($dsn) eq 'CODE';
 
-# update+blob update(s) done atomically on separate connection
-  $self = $self->_writer_storage;
-
-  my $guard = $self->txn_scope_guard;
-
-  my @res;
-  if ($wantarray) {
-    @res    = $self->next::method(@_);
-  }
-  elsif (defined $wantarray) {
-    $res[0] = $self->next::method(@_);
-  }
-  else {
-    $self->next::method(@_);
+  if ($dsn !~ /maxConnect=/) {
+    $self->_dbi_connect_info->[0] = "$dsn;maxConnect=$val";
+    my $connected = defined $self->_dbh;
+    $self->disconnect;
+    $self->ensure_connected if $connected;
   }
-
-  $self->_update_blobs($source, $blob_cols, $where);
-
-  $guard->commit;
-
-  return $wantarray ? @res : $res[0];
 }
 
-### the insert_bulk stuff stolen from DBI/MSSQL.pm
-
-sub _set_identity_insert {
-  my ($self, $table) = @_;
-
-  my $sql = sprintf (
-    'SET IDENTITY_INSERT %s ON',
-    $self->sql_maker->_quote ($table),
-  );
-
-  my $dbh = $self->_get_dbh;
-  eval { $dbh->do ($sql) };
-  if ($@) {
-    $self->throw_exception (sprintf "Error executing '%s': %s",
-      $sql,
-      $dbh->errstr,
-    );
-  }
-}
-
-sub _unset_identity_insert {
-  my ($self, $table) = @_;
-
-  my $sql = sprintf (
-    'SET IDENTITY_INSERT %s OFF',
-    $self->sql_maker->_quote ($table),
-  );
-
-  my $dbh = $self->_get_dbh;
-  $dbh->do ($sql);
-}
-
-# XXX this should use the DBD::Sybase bulk API, where possible
-sub insert_bulk {
+# Whether or not DBD::Sybase was compiled against FreeTDS. If false, it means
+# the Sybase OpenClient libraries were used.
+sub _using_freetds {
   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);
-  }
+  return ($self->_get_dbh->{syb_oc_version}||'') =~ /freetds/i;
 }
 
-### end of stolen insert_bulk section
-
-sub _remove_blob_cols {
-  my ($self, $source, $fields) = @_;
-
-  my %blob_cols;
-
-  for my $col (keys %$fields) {
-    if ($self->_is_lob_type($source->column_info($col)->{data_type})) {
-      $blob_cols{$col} = delete $fields->{$col};
-      $fields->{$col} = \"''";
-    }
-  }
-
-  return keys %blob_cols ? \%blob_cols : undef;
+# Either returns the FreeTDS version against which DBD::Sybase was compiled,
+# 0 if can't be determined, or undef otherwise
+sub _using_freetds_version {
+  my $inf = shift->_get_dbh->{syb_oc_version};
+  return undef unless ($inf||'') =~ /freetds/i;
+  return $inf =~ /v([0-9\.]+)/ ? $1 : 0;
 }
 
-sub _update_blobs {
-  my ($self, $source, $blob_cols, $where) = @_;
-
-  my (@primary_cols) = $source->primary_columns;
+=head1 FURTHER QUESTIONS?
 
-  croak "Cannot update TEXT/IMAGE column(s) without a primary key"
-    unless @primary_cols;
-
-# check if we're updating a single row by PK
-  my $pk_cols_in_where = 0;
-  for my $col (@primary_cols) {
-    $pk_cols_in_where++ if defined $where->{$col};
-  }
-  my @rows;
-
-  if ($pk_cols_in_where == @primary_cols) {
-    my %row_to_update;
-    @row_to_update{@primary_cols} = @{$where}{@primary_cols};
-    @rows = \%row_to_update;
-  } else {
-    my $cursor = $self->select ($source, \@primary_cols, $where, {});
-    @rows = map {
-      my %row; @row{@primary_cols} = @$_; \%row
-    } $cursor->all;
-  }
-
-  for my $row (@rows) {
-    $self->_insert_blobs($source, $blob_cols, $row);
-  }
-}
+Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
 
-sub _insert_blobs {
-  my ($self, $source, $blob_cols, $row) = @_;
-  my $dbh = $self->_get_dbh;
+=head1 COPYRIGHT AND LICENSE
 
-  my $table = $source->from;
-
-  my %row = %$row;
-  my (@primary_cols) = $source->primary_columns;
-
-  croak "Cannot update TEXT/IMAGE column(s) without a primary key"
-    unless @primary_cols;
-
-  if ((grep { defined $row{$_} } @primary_cols) != @primary_cols) {
-    croak "Cannot update TEXT/IMAGE column(s) without primary key values";
-  }
-
-  for my $col (keys %$blob_cols) {
-    my $blob = $blob_cols->{$col};
-
-    my %where = map { ($_, $row{$_}) } @primary_cols;
-
-    my $cursor = $self->select ($source, [$col], \%where, {});
-    $cursor->next;
-    my $sth = $cursor->sth;
-
-    eval {
-      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;
-      $log_on_update    = 1 if not defined $log_on_update;
-
-      $sth->func('CS_SET', 1, {
-        total_txtlen => length($blob),
-        log_on_update => $log_on_update
-      }, 'ct_data_info') or die $sth->errstr;
-
-      $sth->func($blob, length($blob), 'ct_send_data') or die $sth->errstr;
-
-      $sth->func('ct_finish_send') or die $sth->errstr;
-    };
-    my $exception = $@;
-    $sth->finish if $sth;
-    if ($exception) {
-      if ($self->using_freetds) {
-        croak (
-          'TEXT/IMAGE operation failed, probably because you are using FreeTDS: '
-          . $exception
-        );
-      } else {
-        croak $exception;
-      }
-    }
-  }
-}
-
-=head2 connect_call_datetime_setup
-
-Used as:
-
-  on_connect_call => 'datetime_setup'
-
-In L<DBIx::Class::Storage::DBI/connect_info> to set:
-
-  $dbh->syb_date_fmt('ISO_strict'); # output fmt: 2004-08-21T14:36:48.080Z
-  $dbh->do('set dateformat mdy');   # input fmt:  08/13/1979 18:08:55.080
-
-On connection for use with L<DBIx::Class::InflateColumn::DateTime>, using
-L<DateTime::Format::Sybase>, which you will need to install.
-
-This works for both C<DATETIME> and C<SMALLDATETIME> columns, although
-C<SMALLDATETIME> columns only have minute precision.
+This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
+by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
+redistribute it and/or modify it under the same terms as the
+L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.
 
 =cut
 
-{
-  my $old_dbd_warned = 0;
-
-  sub connect_call_datetime_setup {
-    my $self = shift;
-    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 ".
-      "DBIx::Class::InflateColumn::DateTime, please upgrade!";
-      $old_dbd_warned = 1;
-    }
-
-    $dbh->do('SET DATEFORMAT mdy');
-
-    1;
-  }
-}
-
-sub datetime_parser_type { "DateTime::Format::Sybase" }
-
-# ->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(@_);
-}
-
-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) = @_;
-
-  $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
-
-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 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>
-for information on changing the setting on the server side.
-
-=head1 DATES
-
-See L</connect_call_datetime_setup> to setup date formats
-for L<DBIx::Class::InflateColumn::DateTime>.
-
-=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.
-
-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 AUTHOR
-
-See L<DBIx::Class/CONTRIBUTORS>.
-
-=head1 LICENSE
-
-You may distribute this code under the same terms as Perl itself.
-
-=cut
-# vim:sts=2 sw=2: