use strict;
use warnings;
-use base qw/DBIx::Class::Storage::DBI::MSSQL/;
+use base qw/
+ DBIx::Class::Storage::DBI::ODBC
+ DBIx::Class::Storage::DBI::MSSQL
+/;
use mro 'c3';
use Scalar::Util 'reftype';
use Try::Tiny;
-use Carp::Clan qw/^DBIx::Class/;
+use DBIx::Class::Carp;
use namespace::clean;
__PACKAGE__->mk_group_accessors(simple => qw/
statement support. Each has its own advantages and drawbacks and works on
different platforms. Read each section carefully.
+For more details about using MAS in MSSQL over DBD::ODBC see this excellent
+document provided by EasySoft:
+L<http://www.easysoft.com/developer/languages/perl/multiple-active-statements.html>.
+
In order of preference, they are:
=over 8
-=item * L</connect_call_use_mars>
+=item * L<mars|/connect_call_use_mars>
-=item * L</connect_call_use_dynamic_cursors>
+=item * L<dynamic_cursors|/connect_call_use_dynamic_cursors>
-=item * L</connect_call_use_server_cursors>
+=item * L<server_cursors|/connect_call_use_server_cursors>
=back
on_connect_call => 'use_mars'
+in your connection info, or alternatively specify it directly:
+
+ Your::Schema->connect (
+ $original_dsn . '; MARS_Connection=Yes',
+ $user,
+ $pass,
+ \%attrs,
+ )
+
Use to enable a feature of SQL Server 2005 and later, "Multiple Active Result
Sets". See L<DBD::ODBC::FAQ/Does DBD::ODBC support Multiple Active Statements?>
for more information.
}
if ($dsn !~ /MARS_Connection=/) {
- if ($self->using_freetds) {
+ if ($self->_using_freetds) {
$self->throw_exception('FreeTDS does not support MARS at the time of '
.'writing.');
}
on_connect_call => 'use_dynamic_cursors'
-in your L<connect_info|DBIx::Class::Storage::DBI/connect_info> as one way to enable multiple
-concurrent statements.
+Which will add C<< odbc_cursortype => 2 >> to your DBI connection
+attributes, or alternatively specify the necessary flag directly:
-Will add C<< odbc_cursortype => 2 >> to your DBI connection attributes. See
-L<DBD::ODBC/odbc_cursortype> for more information.
+ Your::Schema->connect (@dsn, { ... odbc_cursortype => 2 })
-Alternatively, you can add it yourself and dynamic cursor support will be
-automatically enabled.
+See L<DBD::ODBC/odbc_cursortype> for more information.
If you're using FreeTDS, C<tds_version> must be set to at least C<8.0>.
This will not work with CODE ref connect_info's.
-B<WARNING:> this will break C<SCOPE_IDENTITY()>, and C<SELECT @@IDENTITY> will
-be used instead, which on SQL Server 2005 and later will return erroneous
-results on tables which have an on insert trigger that inserts into another
-table with an C<IDENTITY> column.
+B<WARNING:> on FreeTDS (and maybe some other drivers) this will break
+C<SCOPE_IDENTITY()>, and C<SELECT @@IDENTITY> will be used instead, which on SQL
+Server 2005 and later will return erroneous results on tables which have an on
+insert trigger that inserts into another table with an C<IDENTITY> column.
+
+B<WARNING:> on FreeTDS, changes made in one statement (e.g. an insert) may not
+be visible from a following statement (e.g. a select.)
+
+B<WARNING:> FreeTDS versions > 0.82 seem to have completely broken the ODBC
+protocol. DBIC will not allow dynamic cursor support with such versions to
+protect your data. Please hassle the authors of FreeTDS to act on the bugs that
+make their driver not overly usable with DBD::ODBC.
=cut
sub connect_call_use_dynamic_cursors {
my $self = shift;
- if (ref($self->_dbi_connect_info->[0]) eq 'CODE') {
- $self->throw_exception ('Cannot set DBI attributes on a CODE ref connect_info');
- }
+ if (($self->_dbic_connect_attributes->{odbc_cursortype} || 0) < 2) {
- my $dbi_attrs = $self->_dbi_connect_info->[-1];
+ my $dbi_inf = $self->_dbi_connect_info;
- unless (ref $dbi_attrs eq 'HASH') {
- $dbi_attrs = {};
- push @{ $self->_dbi_connect_info }, $dbi_attrs;
- }
+ $self->throw_exception ('Cannot set DBI attributes on a CODE ref connect_info')
+ if ref($dbi_inf->[0]) eq 'CODE';
+
+ # reenter connection information with the attribute re-set
+ $dbi_inf->[3] = {} if @$dbi_inf <= 3;
+ $dbi_inf->[3]{odbc_cursortype} = 2;
+
+ $self->_dbi_connect_info($dbi_inf);
- if (not exists $dbi_attrs->{odbc_cursortype}) {
- # turn on support for multiple concurrent statements, unless overridden
- $dbi_attrs->{odbc_cursortype} = 2;
$self->disconnect; # resetting dbi attrs, so have to reconnect
$self->ensure_connected;
- $self->_set_dynamic_cursors;
}
}
-sub _set_dynamic_cursors {
+sub _run_connection_actions {
my $self = shift;
- my $dbh = $self->_get_dbh;
-
- try {
- local $dbh->{RaiseError} = 1;
- local $dbh->{PrintError} = 0;
- $dbh->do('SELECT @@IDENTITY');
- } catch {
- $self->throw_exception (<<'EOF');
-
-Your drivers do not seem to support dynamic cursors (odbc_cursortype => 2),
-if you're using FreeTDS, make sure to set tds_version to 8.0 or greater.
-EOF
- };
-
- $self->_using_dynamic_cursors(1);
- $self->_identity_method('@@identity');
-}
-sub _init {
- my $self = shift;
+ $self->next::method (@_);
+ # keep the dynamic_cursors_support and driver-state in sync
+ # on every reconnect
+ my $use_dyncursors = ($self->_dbic_connect_attributes->{odbc_cursortype} || 0) > 1;
if (
- ref($self->_dbi_connect_info->[0]) ne 'CODE'
- &&
- ref ($self->_dbi_connect_info->[-1]) eq 'HASH'
- &&
- ($self->_dbi_connect_info->[-1]{odbc_cursortype} || 0) > 1
+ $use_dyncursors
+ xor
+ !!$self->_using_dynamic_cursors
) {
- $self->_set_dynamic_cursors;
+ if ($use_dyncursors) {
+ try {
+ my $dbh = $self->_dbh;
+ local $dbh->{RaiseError} = 1;
+ local $dbh->{PrintError} = 0;
+ $dbh->do('SELECT @@IDENTITY');
+ } catch {
+ $self->throw_exception (
+ 'Your drivers do not seem to support dynamic cursors (odbc_cursortype => 2).'
+ . (
+ $self->_using_freetds
+ ? ' If you are using FreeTDS, make sure to set tds_version to 8.0 or greater.'
+ : ''
+ )
+ );
+ };
+
+ $self->_using_dynamic_cursors(1);
+ $self->_identity_method('@@identity');
+ }
+ else {
+ $self->_using_dynamic_cursors(0);
+ $self->_identity_method(undef);
+ }
}
- else {
- $self->_using_dynamic_cursors(0);
+
+ $self->_no_scope_identity_query($self->_using_dynamic_cursors
+ ? $self->_using_freetds
+ : undef
+ );
+
+ # freetds is too damn broken, some fixups
+ if ($self->_using_freetds) {
+
+ # no dynamic cursors starting from 0.83
+ if ($self->_using_dynamic_cursors) {
+ my $fv = $self->_using_freetds_version || 999; # assume large if can't be determined
+ $self->throw_exception(
+ 'Dynamic cursors (odbc_cursortype => 2) are not supported with FreeTDS > 0.82 '
+ . "(you have $fv). Please hassle FreeTDS authors to fix the outstanding bugs in "
+ . 'their driver.'
+ ) if $fv > 0.82
+ }
+
+ # FreeTDS is too broken wrt execute_for_fetch batching
+ # just disable it outright until things quiet down
+ $self->_disable_odbc_array_ops;
}
}
$self->_get_dbh->{odbc_SQL_ROWSET_SIZE} = $sql_rowset_size;
}
-=head2 using_freetds
-
-Tries to determine, to the best of our ability, whether or not you are using the
-FreeTDS driver with L<DBD::ODBC>.
-
-=cut
-
-sub using_freetds {
- my $self = shift;
-
- my $dsn = $self->_dbi_connect_info->[0];
-
- $dsn = '' if ref $dsn eq 'CODE';
-
- my $dbh = $self->_get_dbh;
-
- return 1 if $dsn =~ /driver=FreeTDS/i
- || (try { $dbh->get_info(6) }||'') =~ /tdsodbc/i;
-
- return 0;
-}
-
1;
=head1 AUTHOR
-See L<DBIx::Class/CONTRIBUTORS>.
+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: sw=2 sts=2
+# vim:sw=2 sts=2 et
projects / dbsrgits/DBIx-Class.git / blobdiff