Merge 'trunk' into 'sybase'

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Storage / DBI / Sybase.pm

package DBIx::Class::Storage::DBI::Sybase;

use strict;
use warnings;

use Class::C3;
use base qw/DBIx::Class::Storage::DBI/;

use Carp::Clan qw/^DBIx::Class/;

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]
    } || '';

    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
      if (not $self->dbh->{syb_dynamic_supported}) {
        bless $self, 'DBIx::Class::Storage:DBI::Sybase::NoBindVars';
        $self->_rebless;
      }
      $self->connect_call_datetime_setup;
      $self->connect_call_blob_setup;
    }
  }
}

sub _populate_dbh {
  my $self = shift;
  $self->next::method(@_);
  $self->connect_call_datetime_setup;
  $self->connect_call_blob_setup;
  1;
}

=head2 connect_call_blob_setup

Used as:

  on_connect_call => 'blob_setup'

Does C<< $dbh->{syb_binary_images} = 1; >> to return C<IMAGE> data as raw binary
instead of as a hex string.

Recommended.

=cut

sub connect_call_blob_setup {
  my $self = shift;
  my $dbh = $self->_dbh;
  $dbh->{syb_binary_images} = 1;
}

=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.

=cut

{
  my $old_dbd_warned = 0;

  sub connect_call_datetime_setup {
    my $self = shift;
    my $dbh = $self->_dbh;

    if ($dbh->can('syb_date_fmt')) {
      $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" }

sub _dbh_last_insert_id {
  my ($self, $dbh, $source, $col) = @_;

  # sorry, there's no other way!
  my $sth = $dbh->prepare_cached("select max($col) from ".$source->from);
  return ($dbh->selectrow_array($sth))[0];
}

=head2 count

Counts for limited queries are emulated by executing select queries and
returning the number of successful executions minus the offset.

This is necessary due to the limitations of Sybase.

=cut

sub count {
  my $self = shift;
  my ($source, $attrs) = @_;

  if (not exists $attrs->{rows}) {
    return $self->next::method(@_);
  }

  my $offset = $attrs->{offset} || 0;
  my $total  = $attrs->{rows} + $offset;

  my $new_attrs = $self->_copy_attributes_for_count($source, $attrs);

  my $first_pk = ($source->primary_columns)[0];

  $new_attrs->{select} = $first_pk ? "me.$first_pk" : 1;

  my $tmp_rs = $source->resultset_class->new($source, $new_attrs);

  $self->dbh->{syb_rowcount} = $total;

  my $count = 0;
  $count++ while $tmp_rs->cursor->next;

  $self->dbh->{syb_rowcount} = 0;

  return $count - $offset;
}

1;

=head1 NAME

DBIx::Class::Storage::DBI::Sybase - Storage::DBI subclass for Sybase

=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>.

=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)>.

But your queries will be cached.

A recommended L<DBIx::Class::Storage::DBI/connect_info> setting:

  on_connect_call => [qw/datetime_setup blob_setup/]

=head1 DATES

See L</connect_call_datetime_setup> to setup date formats
for L<DBIx::Class::InflateColumn::DateTime>.

=head1 IMAGE AND TEXT COLUMNS

See L</connect_call_blob_setup> for a L<DBIx::Class::Storage::DBI/connect_info>
setting you need to work with C<IMAGE> columns.

Due to limitations in L<DBD::Sybase> and this driver, it is only possible to
select one C<TEXT> or C<IMAGE> column at a time.

=head1 AUTHORS

See L<DBIx::Class/CONTRIBUTORS>.

=head1 LICENSE

You may distribute this code under the same terms as Perl itself.

=cut
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