As shitty as freetds is, it seems they at least got MARS right

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Storage / DBI / ODBC / Microsoft_SQL_Server.pm

diff --git a/lib/DBIx/Class/Storage/DBI/ODBC/Microsoft_SQL_Server.pm b/lib/DBIx/Class/Storage/DBI/ODBC/Microsoft_SQL_Server.pm
index 33b53e3..1b5fba2 100644 (file)
--- a/lib/DBIx/Class/Storage/DBI/ODBC/Microsoft_SQL_Server.pm
+++ b/lib/DBIx/Class/Storage/DBI/ODBC/Microsoft_SQL_Server.pm
@@ -2,11 +2,14 @@ package DBIx::Class::Storage::DBI::ODBC::Microsoft_SQL_Server;
 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/
@@ -124,9 +127,10 @@ sub connect_call_use_mars {
   }
 
   if ($dsn !~ /MARS_Connection=/) {
-    if ($self->using_freetds) {
-      $self->throw_exception('FreeTDS does not support MARS at the time of '
-                            .'writing.');
+    if ($self->_using_freetds) {
+      my $v = $self->_using_freetds_version;
+      $self->throw_exception("FreeTDS 0.91 or later required for MARS support, you have $v")
+        if $v < 0.91;
     }
 
     if (exists $self->_server_info->{normalized_dbms_version} &&
@@ -174,27 +178,32 @@ 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;
 
-  my $conn_info = $self->_dbi_connect_info;
+  if (($self->_dbic_connect_attributes->{odbc_cursortype} || 0) < 2) {
 
-  if (ref($conn_info->[0]) eq 'CODE') {
-    $self->throw_exception ('Cannot set DBI attributes on a CODE ref connect_info');
-  }
+    my $dbi_inf = $self->_dbi_connect_info;
+
+    $self->throw_exception ('Cannot set DBI attributes on a CODE ref connect_info')
+      if ref($dbi_inf->[0]) eq 'CODE';
 
-  if (
-    ref($conn_info->[-1]) ne 'HASH'
-      or
-    ($conn_info->[-1]{odbc_cursortype}||0) < 2
-  ) {
     # reenter connection information with the attribute re-set
-    $self->connect_info(
-      @{$conn_info}[0,1,2],
-      { %{$self->_dbix_connect_attributes}, odbc_cursortype => 2 },
-    );
+    $dbi_inf->[3] = {} if @$dbi_inf <= 3;
+    $dbi_inf->[3]{odbc_cursortype} = 2;
+
+    $self->_dbi_connect_info($dbi_inf);
+
     $self->disconnect; # resetting dbi attrs, so have to reconnect
     $self->ensure_connected;
   }
@@ -221,7 +230,7 @@ sub _run_connection_actions {
         $self->throw_exception (
           'Your drivers do not seem to support dynamic cursors (odbc_cursortype => 2).'
          . (
-          $self->using_freetds
+          $self->_using_freetds
             ? ' If you are using FreeTDS, make sure to set tds_version to 8.0 or greater.'
             : ''
           )
@@ -230,14 +239,34 @@ sub _run_connection_actions {
 
       $self->_using_dynamic_cursors(1);
       $self->_identity_method('@@identity');
+      $self->_no_scope_identity_query($self->_using_freetds);
     }
     else {
       $self->_using_dynamic_cursors(0);
       $self->_identity_method(undef);
+      $self->_no_scope_identity_query(undef);
     }
   }
 
   $self->next::method (@_);
+
+  # freetds is too damn broken, some fixups
+  if ($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->_get_dbh->{odbc_disable_array_operations} = 1;
+  }
 }
 
 =head2 connect_call_use_server_cursors
@@ -272,37 +301,15 @@ sub connect_call_use_server_cursors {
   $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