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 unsafe_insert _insert_dbh/
+ 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
+/;
+
=head1 NAME
DBIx::Class::Storage::DBI::Sybase - Sybase support for DBIx::Class
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.) The transaction can be turned off if concurrency is not an
-issue, or you don't need the C<IDENTITY> value, see
-L<DBIx::Class::Storage::DBI::Sybase/connect_call_unsafe_insert>.
-
-But your queries will be cached.
+(locking the table.) See L</INSERTS WITH PLACEHOLDERS>.
A recommended L<DBIx::Class::Storage::DBI/connect_info> setting:
$self->_rebless;
}
}
-
- $self->set_textsize; # based on LongReadLen in connect_info
-
}
elsif (not $self->_get_dbh->{syb_dynamic_supported}) {
# not necessarily FreeTDS, but no placeholders nevertheless
# this is highly unlikely, but we check just in case
$self->auto_cast(1);
}
-
- $self->_set_max_connect(256);
}
}
}
+sub _init {
+ my $self = shift;
+ $self->_set_max_connect(256);
+
+ # based on LongReadLen in connect_info
+ $self->set_textsize if $self->using_freetds;
+
+# create storage for insert/(update blob) transactions,
+# unless this is that storage
+ return if $self->_is_writer_storage;
+
+ 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);
+
+ *{$method} = Sub::Name::subname __PACKAGE__."::$method" => sub {
+ my $self = shift;
+ $self->_writer_storage->$replaced(@_) if $self->_writer_storage;
+ return $self->$replaced(@_);
+ };
+}
+
# 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
$self->_dbh->do('SET CHAINED ON');
}
}
-
- $self->_insert_dbh($self->_connect(@{ $self->_dbi_connect_info }));
}
=head2 connect_call_blob_setup
if exists $args{log_on_update};
}
-=head2 connect_call_unsafe_insert
-
-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)> when placeholders are enabled.
-
-When using C<DBIx::Class::Storage::DBI::Sybase::NoBindVars> transactions are
-disabled.
-
-To turn off transactions for inserts (for an application that doesn't need
-concurrency, or a loader, for example) use this setting in
-L<DBIx::Class::Storage::DBI/connect_info>,
-
- on_connect_call => ['unsafe_insert']
-
-To manipulate this setting at runtime, use:
-
- $schema->storage->unsafe_insert(0|1);
-
-=cut
-
-sub connect_call_unsafe_insert {
- my $self = shift;
- $self->unsafe_insert(1);
-}
-
sub _is_lob_type {
my $self = shift;
my $type = shift;
sub _fetch_identity_sql {
my ($self, $source, $col) = @_;
- return "SELECT MAX($col) FROM ".$source->from;
+ return sprintf ("SELECT MAX(%s) FROM %s",
+ map { $self->sql_maker->_quote ($_) } ($col, $source->from)
+ );
}
sub _execute {
my $blob_cols = $self->_remove_blob_cols($source, $to_insert);
-# insert+blob insert done atomically
- my $guard = $self->txn_scope_guard if $blob_cols;
+ my $identity_col = List::Util::first
+ { $source->column_info($_)->{is_auto_increment} }
+ $source->columns;
- my $need_last_insert_id = 0;
+ # 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, $identity_col
+ );
+ }
- my ($identity_col) =
- map $_->[0],
- grep $_->[1]{is_auto_increment},
- map [ $_, $source->column_info($_) ],
- $source->columns;
+ # otherwise use the _writer_storage to do the insert+transaction on another
+ # connection
+ my $guard = $self->_writer_storage->txn_scope_guard;
- $need_last_insert_id = 1
- if $identity_col && (not exists $to_insert->{$identity_col});
-
- # We have to do the insert in a transaction to avoid race conditions with the
- # SELECT MAX(COL) identity method used when placeholders are enabled.
- my $updated_cols = do {
- if (
- $need_last_insert_id && !$self->unsafe_insert && !$self->{transaction_depth}
- ) {
- local $self->{_dbh} = $self->_insert_dbh;
- my $guard = $self->txn_scope_guard;
- my $upd_cols = $self->next::method (@_);
- $guard->commit;
- $upd_cols;
- }
- else {
- $self->next::method(@_);
- }
- };
+ 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 if $guard;
+ $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 $updated_cols;
}
my ($source, $fields, $where) = @_;
my $wantarray = wantarray;
-
my $blob_cols = $self->_remove_blob_cols($source, $fields);
-# update+blob update(s) done atomically
- my $guard = $self->txn_scope_guard if $blob_cols;
+ if (not $blob_cols) {
+ return $self->next::method(@_);
+ }
+
+# update+blob update(s) done atomically on separate connection
+ $self = $self->_writer_storage;
+
+ my $guard = $self->txn_scope_guard;
my @res;
if ($wantarray) {
$self->next::method(@_);
}
- $self->_update_blobs($source, $blob_cols, $where) if $blob_cols;
+ $self->_update_blobs($source, $blob_cols, $where);
- $guard->commit if $guard;
+ $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 {
+ 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
+
sub _remove_blob_cols {
my ($self, $source, $fields) = @_;
@row_to_update{@primary_cols} = @{$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) {
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";
- }
+ 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 = $source->resultset->search(\%where, {
- select => [$col]
- })->cursor;
+
+ my $cursor = $self->select ($source, [$col], \%where, {});
$cursor->next;
my $sth = $cursor->sth;
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
C<next> or C<first> but has not been exhausted or
L<reset|DBIx::Class::ResultSet/reset>.
-Transactions done for inserts in C<AutoCommit> mode when placeholders are in use
-are also affected, so this won't work:
+For example, this will not work:
- while (my $row = $rs1->next) {
- $rs2->create({ foo => $row->foo });
- }
+ $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 * set C<< $schema->storage->unsafe_insert(1) >> temporarily (see
-L</connect_call_unsafe_insert>)
-
=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>
-=item * enlarge the scope of the transaction
-
=back
=head1 MAXIMUM CONNECTIONS