Merge branch 'master' into topic/constructor_rewrite

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

diff --git a/lib/DBIx/Class/Storage/DBI/ACCESS.pm b/lib/DBIx/Class/Storage/DBI/ACCESS.pm
new file mode 100644 (file)
index 0000000..a6f174e
--- /dev/null
+++ b/lib/DBIx/Class/Storage/DBI/ACCESS.pm
@@ -0,0 +1,138 @@
+package DBIx::Class::Storage::DBI::ACCESS;
+
+use strict;
+use warnings;
+use base 'DBIx::Class::Storage::DBI::UniqueIdentifier';
+use mro 'c3';
+
+use DBI ();
+use List::Util 'first';
+use namespace::clean;
+
+__PACKAGE__->sql_limit_dialect ('Top');
+__PACKAGE__->sql_maker_class('DBIx::Class::SQLMaker::ACCESS');
+__PACKAGE__->sql_quote_char ([qw/[ ]/]);
+
+sub sqlt_type { 'ACCESS' }
+
+__PACKAGE__->new_guid(undef);
+
+=head1 NAME
+
+DBIx::Class::Storage::DBI::ACCESS - Support specific to MS Access
+
+=head1 DESCRIPTION
+
+This is the base class for Microsoft Access support.
+
+This driver supports L<last_insert_id|DBIx::Class::Storage::DBI/last_insert_id>,
+empty inserts for tables with C<AUTOINCREMENT> columns, nested transactions via
+L<auto_savepoint|DBIx::Class::Storage::DBI/auto_savepoint>, C<GUID> columns via
+L<DBIx::Class::Storage::DBI::UniqueIdentifier>.
+
+=head1 SUPPORTED VERSIONS
+
+This module has currently only been tested on MS Access 2010.
+
+Information about how well it works on different version of MS Access is welcome
+(write the mailing list, or submit a ticket to RT if you find bugs.)
+
+=head1 USING GUID COLUMNS
+
+If you have C<GUID> PKs or other C<GUID> columns with
+L<auto_nextval|DBIx::Class::ResultSource/auto_nextval> you will need to set a
+L<new_guid|DBIx::Class::Storage::DBI::UniqueIdentifier/new_guid> callback, like
+so:
+
+  $schema->storage->new_guid(sub { Data::GUID->new->as_string });
+
+Under L<Catalyst> you can use code similar to this in your
+L<Catalyst::Model::DBIC::Schema> C<Model.pm>:
+
+  after BUILD => sub {
+    my $self = shift;
+    $self->storage->new_guid(sub { Data::GUID->new->as_string });
+  };
+
+=cut
+
+sub _dbh_last_insert_id { $_[1]->selectrow_array('select @@identity') }
+
+# support empty insert
+sub insert {
+  my $self = shift;
+  my ($source, $to_insert) = @_;
+
+  my $columns_info = $source->columns_info;
+
+  if (keys %$to_insert == 0) {
+    my $autoinc_col = first {
+      $columns_info->{$_}{is_auto_increment}
+    } keys %$columns_info;
+
+    if (not $autoinc_col) {
+      $self->throw_exception(
+'empty insert only supported for tables with an autoincrement column'
+      );
+    }
+
+    my $table = $source->from;
+    $table = $$table if ref $table;
+
+    $to_insert->{$autoinc_col} = \"dmax('${autoinc_col}', '${table}')+1";
+  }
+
+  return $self->next::method(@_);
+}
+
+sub bind_attribute_by_data_type {
+  my $self = shift;
+  my ($data_type) = @_;
+
+  my $attributes = $self->next::method(@_) || {};
+
+  if ($self->_is_text_lob_type($data_type)) {
+    $attributes->{TYPE} = DBI::SQL_LONGVARCHAR;
+  }
+  elsif ($self->_is_binary_lob_type($data_type)) {
+    $attributes->{TYPE} = DBI::SQL_LONGVARBINARY;
+  }
+
+  return $attributes;
+}
+
+# savepoints are not supported, but nested transactions are.
+# Unfortunately DBI does not support nested transactions.
+# WARNING: this code uses the undocumented 'BegunWork' DBI attribute.
+
+sub _exec_svp_begin {
+  my ($self, $name) = @_;
+
+  local $self->_dbh->{AutoCommit} = 1;
+  local $self->_dbh->{BegunWork}  = 0;
+  $self->_exec_txn_begin;
+}
+
+# A new nested transaction on the same level releases the previous one.
+sub _exec_svp_release { 1 }
+
+sub _exec_svp_rollback {
+  my ($self, $name) = @_;
+
+  local $self->_dbh->{AutoCommit} = 0;
+  local $self->_dbh->{BegunWork}  = 1;
+  $self->_exec_txn_rollback;
+}
+
+1;
+
+=head1 AUTHOR
+
+See L<DBIx::Class/AUTHOR> and L<DBIx::Class/CONTRIBUTORS>.
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut
+# vim:sts=2 sw=2: