1 package DBIx::Class::Storage::DBI::ODBC::Microsoft_SQL_Server;
5 use base qw/DBIx::Class::Storage::DBI::MSSQL/;
13 __PACKAGE__->mk_group_accessors(simple => qw/
14 _using_dynamic_cursors
19 DBIx::Class::Storage::DBI::ODBC::Microsoft_SQL_Server - Support specific
20 to Microsoft SQL Server over ODBC
24 This class implements support specific to Microsoft SQL Server over ODBC. It is
25 loaded automatically by by DBIx::Class::Storage::DBI::ODBC when it detects a
28 Most of the functionality is provided from the superclass
29 L<DBIx::Class::Storage::DBI::MSSQL>.
31 =head1 MULTIPLE ACTIVE STATEMENTS
33 The following options are alternative ways to enable concurrent executing
34 statement support. Each has its own advantages and drawbacks.
36 =head2 connect_call_use_dynamic_cursors
40 on_connect_call => 'use_dynamic_cursors'
42 in your L<connect_info|DBIx::Class::Storage::DBI/connect_info> as one way to enable multiple
43 concurrent statements.
45 Will add C<< odbc_cursortype => 2 >> to your DBI connection attributes. See
46 L<DBD::ODBC/odbc_cursortype> for more information.
48 Alternatively, you can add it yourself and dynamic cursor support will be
49 automatically enabled.
51 If you're using FreeTDS, C<tds_version> must be set to at least C<8.0>.
53 This will not work with CODE ref connect_info's.
55 B<WARNING:> this will break C<SCOPE_IDENTITY()>, and C<SELECT @@IDENTITY> will
56 be used instead, which on SQL Server 2005 and later will return erroneous
57 results on tables which have an on insert trigger that inserts into another
58 table with an C<IDENTITY> column.
62 sub connect_call_use_dynamic_cursors {
65 if (ref($self->_dbi_connect_info->[0]) eq 'CODE') {
66 $self->throw_exception ('Cannot set DBI attributes on a CODE ref connect_info');
69 my $dbi_attrs = $self->_dbi_connect_info->[-1];
71 unless (ref($dbi_attrs) && Scalar::Util::reftype($dbi_attrs) eq 'HASH') {
73 push @{ $self->_dbi_connect_info }, $dbi_attrs;
76 if (not exists $dbi_attrs->{odbc_cursortype}) {
77 # turn on support for multiple concurrent statements, unless overridden
78 $dbi_attrs->{odbc_cursortype} = 2;
79 $self->disconnect; # resetting dbi attrs, so have to reconnect
80 $self->ensure_connected;
81 $self->_set_dynamic_cursors;
85 sub _set_dynamic_cursors {
87 my $dbh = $self->_get_dbh;
90 local $dbh->{RaiseError} = 1;
91 local $dbh->{PrintError} = 0;
92 $dbh->do('SELECT @@IDENTITY');
94 $self->throw_exception (<<'EOF');
96 Your drivers do not seem to support dynamic cursors (odbc_cursortype => 2),
97 if you're using FreeTDS, make sure to set tds_version to 8.0 or greater.
101 $self->_using_dynamic_cursors(1);
102 $self->_identity_method('@@identity');
108 no warnings qw/uninitialized/;
111 ref($self->_dbi_connect_info->[0]) ne 'CODE'
113 ref ($self->_dbi_connect_info->[-1]) eq 'HASH'
115 $self->_dbi_connect_info->[-1]{odbc_cursortype} == 2
117 $self->_set_dynamic_cursors;
121 $self->_using_dynamic_cursors(0);
124 =head2 connect_call_use_server_cursors
128 on_connect_call => 'use_server_cursors'
130 May allow multiple active select statements. See
131 L<DBD::ODBC/odbc_SQL_ROWSET_SIZE> for more information.
133 Takes an optional parameter for the value to set the attribute to, default is
136 B<WARNING>: this does not work on all versions of SQL Server, and may lock up
141 sub connect_call_use_server_cursors {
143 my $sql_rowset_size = shift || 2;
145 $self->_get_dbh->{odbc_SQL_ROWSET_SIZE} = $sql_rowset_size;
148 =head2 connect_call_use_MARS
152 on_connect_call => 'use_MARS'
154 Use to enable a feature of SQL Server 2005 and later, "Multiple Active Result
155 Sets". See L<DBD::ODBC::FAQ/Does DBD::ODBC support Multiple Active Statements?>
156 for more information.
158 B<WARNING>: This has implications for the way transactions are handled.
162 sub connect_call_use_MARS {
165 my $dsn = $self->_dbi_connect_info->[0];
167 if (ref($dsn) eq 'CODE') {
168 $self->throw_exception('cannot change the DBI DSN on a CODE ref connect_info');
171 if ($dsn !~ /MARS_Connection=/) {
172 $self->_dbi_connect_info->[0] = "$dsn;MARS_Connection=Yes";
173 my $was_connected = defined $self->_dbh;
175 $self->ensure_connected if $was_connected;
183 See L<DBIx::Class/CONTRIBUTORS>.
187 You may distribute this code under the same terms as Perl itself.