1 package DBIx::Class::Storage::DBI::ODBC::Microsoft_SQL_Server;
5 use base qw/DBIx::Class::Storage::DBI::MSSQL/;
12 __PACKAGE__->mk_group_accessors(simple => qw/
13 _using_dynamic_cursors
18 DBIx::Class::Storage::DBI::ODBC::Microsoft_SQL_Server - Support specific
19 to Microsoft SQL Server over ODBC
23 This class implements support specific to Microsoft SQL Server over ODBC. It is
24 loaded automatically by by DBIx::Class::Storage::DBI::ODBC when it detects a
27 Most of the functionality is provided from the superclass
28 L<DBIx::Class::Storage::DBI::MSSQL>.
30 =head1 MULTIPLE ACTIVE STATEMENTS
32 The following options are alternative ways to enable concurrent executing
33 statement support. Each has its own advantages and drawbacks.
35 =head2 connect_call_use_dynamic_cursors
39 on_connect_call => 'use_dynamic_cursors'
41 in your L<connect_info|DBIx::Class::Storage::DBI/connect_info> as one way to enable multiple
42 concurrent statements.
44 Will add C<< odbc_cursortype => 2 >> to your DBI connection attributes. See
45 L<DBD::ODBC/odbc_cursortype> for more information.
47 Alternatively, you can add it yourself and dynamic cursor support will be
48 automatically enabled.
50 If you're using FreeTDS, C<tds_version> must be set to at least C<8.0>.
52 This will not work with CODE ref connect_info's.
54 B<WARNING:> this will break C<SCOPE_IDENTITY()>, and C<SELECT @@IDENTITY> will
55 be used instead, which on SQL Server 2005 and later will return erroneous
56 results on tables which have an on insert trigger that inserts into another
57 table with an C<IDENTITY> column.
61 sub connect_call_use_dynamic_cursors {
64 if (ref($self->_dbi_connect_info->[0]) eq 'CODE') {
65 $self->throw_exception ('Cannot set DBI attributes on a CODE ref connect_info');
68 my $dbi_attrs = $self->_dbi_connect_info->[-1];
70 unless (ref($dbi_attrs) && Scalar::Util::reftype($dbi_attrs) eq 'HASH') {
72 push @{ $self->_dbi_connect_info }, $dbi_attrs;
75 if (not exists $dbi_attrs->{odbc_cursortype}) {
76 # turn on support for multiple concurrent statements, unless overridden
77 $dbi_attrs->{odbc_cursortype} = 2;
78 $self->disconnect; # resetting dbi attrs, so have to reconnect
79 $self->ensure_connected;
80 $self->_set_dynamic_cursors;
84 sub _set_dynamic_cursors {
86 my $dbh = $self->_get_dbh;
89 local $dbh->{RaiseError} = 1;
90 local $dbh->{PrintError} = 0;
91 $dbh->do('SELECT @@IDENTITY');
93 $self->throw_exception (<<'EOF');
95 Your drivers do not seem to support dynamic cursors (odbc_cursortype => 2),
96 if you're using FreeTDS, make sure to set tds_version to 8.0 or greater.
100 $self->_using_dynamic_cursors(1);
101 $self->_identity_method('@@identity');
107 no warnings qw/uninitialized/;
110 ref($self->_dbi_connect_info->[0]) ne 'CODE'
112 ref ($self->_dbi_connect_info->[-1]) eq 'HASH'
114 $self->_dbi_connect_info->[-1]{odbc_cursortype} == 2
116 $self->_set_dynamic_cursors;
120 $self->_using_dynamic_cursors(0);
123 =head2 connect_call_use_server_cursors
127 on_connect_call => 'use_server_cursors'
129 May allow multiple active select statements. See
130 L<DBD::ODBC/odbc_SQL_ROWSET_SIZE> for more information.
132 Takes an optional parameter for the value to set the attribute to, default is
135 B<WARNING>: this does not work on all versions of SQL Server, and may lock up
140 sub connect_call_use_server_cursors {
142 my $sql_rowset_size = shift || 2;
144 $self->_get_dbh->{odbc_SQL_ROWSET_SIZE} = $sql_rowset_size;
147 =head2 connect_call_use_MARS
151 on_connect_call => 'use_MARS'
153 Use to enable a feature of SQL Server 2005 and later, "Multiple Active Result
154 Sets". See L<DBD::ODBC::FAQ/Does DBD::ODBC support Multiple Active Statements?>
155 for more information.
157 B<WARNING>: This has implications for the way transactions are handled.
161 sub connect_call_use_MARS {
164 my $dsn = $self->_dbi_connect_info->[0];
166 if (ref($dsn) eq 'CODE') {
167 $self->throw_exception('cannot change the DBI DSN on a CODE ref connect_info');
170 if ($dsn !~ /MARS_Connection=/) {
171 $self->_dbi_connect_info->[0] = "$dsn;MARS_Connection=Yes";
172 my $was_connected = defined $self->_dbh;
174 $self->ensure_connected if $was_connected;
182 See L<DBIx::Class/CONTRIBUTORS>.
186 You may distribute this code under the same terms as Perl itself.