1 package DBIx::Class::Storage::DBI::ODBC::Microsoft_SQL_Server;
5 use base qw/DBIx::Class::Storage::DBI::MSSQL/;
7 use Scalar::Util 'reftype';
9 use Carp::Clan qw/^DBIx::Class/;
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 and works on
34 different platforms. Read each section carefully.
36 In order of preference, they are:
40 =item * L</connect_call_use_mars>
42 =item * L</connect_call_use_dynamic_cursors>
44 =item * L</connect_call_use_server_cursors>
50 =head2 connect_call_use_mars
54 on_connect_call => 'use_mars'
56 Use to enable a feature of SQL Server 2005 and later, "Multiple Active Result
57 Sets". See L<DBD::ODBC::FAQ/Does DBD::ODBC support Multiple Active Statements?>
60 This does not work on FreeTDS drivers at the time of this writing, and only
61 works with the Native Client, later versions of the Windows MS ODBC driver, and
66 sub connect_call_use_mars {
69 my $dsn = $self->_dbi_connect_info->[0];
71 if (ref($dsn) eq 'CODE') {
72 $self->throw_exception('cannot change the DBI DSN on a CODE ref connect_info');
75 if ($dsn !~ /MARS_Connection=/) {
76 if ($self->using_freetds) {
77 $self->throw_exception('FreeTDS does not support MARS at the time of '
81 if (exists $self->_server_info->{normalized_dbms_version} &&
82 $self->_server_info->{normalized_dbms_version} < 9) {
83 $self->throw_exception('SQL Server 2005 or later required to use MARS.');
86 if (my ($data_source) = $dsn =~ /^dbi:ODBC:([\w-]+)\z/i) { # prefix with DSN
87 warn "Bare DSN in ODBC connect string, rewriting to DSN=$data_source\n";
88 $dsn = "dbi:ODBC:DSN=$data_source";
91 $self->_dbi_connect_info->[0] = "$dsn;MARS_Connection=Yes";
93 $self->ensure_connected;
97 sub connect_call_use_MARS {
98 carp "'connect_call_use_MARS' has been deprecated, use "
99 ."'connect_call_use_mars' instead.";
100 shift->connect_call_use_mars(@_)
103 =head2 connect_call_use_dynamic_cursors
107 on_connect_call => 'use_dynamic_cursors'
109 in your L<connect_info|DBIx::Class::Storage::DBI/connect_info> as one way to enable multiple
110 concurrent statements.
112 Will add C<< odbc_cursortype => 2 >> to your DBI connection attributes. See
113 L<DBD::ODBC/odbc_cursortype> for more information.
115 Alternatively, you can add it yourself and dynamic cursor support will be
116 automatically enabled.
118 If you're using FreeTDS, C<tds_version> must be set to at least C<8.0>.
120 This will not work with CODE ref connect_info's.
122 B<WARNING:> this will break C<SCOPE_IDENTITY()>, and C<SELECT @@IDENTITY> will
123 be used instead, which on SQL Server 2005 and later will return erroneous
124 results on tables which have an on insert trigger that inserts into another
125 table with an C<IDENTITY> column.
129 sub connect_call_use_dynamic_cursors {
132 if (ref($self->_dbi_connect_info->[0]) eq 'CODE') {
133 $self->throw_exception ('Cannot set DBI attributes on a CODE ref connect_info');
136 my $dbi_attrs = $self->_dbi_connect_info->[-1];
138 unless (ref $dbi_attrs eq 'HASH') {
140 push @{ $self->_dbi_connect_info }, $dbi_attrs;
143 if (not exists $dbi_attrs->{odbc_cursortype}) {
144 # turn on support for multiple concurrent statements, unless overridden
145 $dbi_attrs->{odbc_cursortype} = 2;
146 $self->disconnect; # resetting dbi attrs, so have to reconnect
147 $self->ensure_connected;
148 $self->_set_dynamic_cursors;
152 sub _set_dynamic_cursors {
154 my $dbh = $self->_get_dbh;
157 local $dbh->{RaiseError} = 1;
158 local $dbh->{PrintError} = 0;
159 $dbh->do('SELECT @@IDENTITY');
161 $self->throw_exception (<<'EOF');
163 Your drivers do not seem to support dynamic cursors (odbc_cursortype => 2),
164 if you're using FreeTDS, make sure to set tds_version to 8.0 or greater.
168 $self->_using_dynamic_cursors(1);
169 $self->_identity_method('@@identity');
176 ref($self->_dbi_connect_info->[0]) ne 'CODE'
178 ref ($self->_dbi_connect_info->[-1]) eq 'HASH'
180 ($self->_dbi_connect_info->[-1]{odbc_cursortype} || 0) > 1
182 $self->_set_dynamic_cursors;
185 $self->_using_dynamic_cursors(0);
189 =head2 connect_call_use_server_cursors
193 on_connect_call => 'use_server_cursors'
195 May allow multiple active select statements. See
196 L<DBD::ODBC/odbc_SQL_ROWSET_SIZE> for more information.
198 Takes an optional parameter for the value to set the attribute to, default is
201 B<WARNING>: this does not work on all versions of SQL Server, and may lock up
204 At the time of writing, this option only works on Microsoft's Windows drivers,
205 later versions of the ODBC driver and the Native Client driver.
209 sub connect_call_use_server_cursors {
211 my $sql_rowset_size = shift || 2;
213 if ($^O !~ /win32|cygwin/i) {
214 $self->throw_exception('Server cursors only work on Windows platforms at '
215 .'the time of writing.');
218 $self->_get_dbh->{odbc_SQL_ROWSET_SIZE} = $sql_rowset_size;
223 Tries to determine, to the best of our ability, whether or not you are using the
224 FreeTDS driver with L<DBD::ODBC>.
231 my $dsn = $self->_dbi_connect_info->[0];
233 $dsn = '' if ref $dsn eq 'CODE';
235 my $dbh = $self->_get_dbh;
237 return 1 if $dsn =~ /driver=FreeTDS/i
238 || (try { $dbh->get_info(6) }||'') =~ /tdsodbc/i;
247 See L<DBIx::Class/CONTRIBUTORS>.
251 You may distribute this code under the same terms as Perl itself.