From: Rafael Kitover <rkitover@cpan.org>
Date: Fri, 24 Jul 2009 06:46:16 +0000 (+0000)
Subject: merge in some more MSSQL code, including odbc dynamic cursor support
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=7b1b2582a2f787fcacd238f1635fbce4cb9e0985;p=dbsrgits%2FDBIx-Class-Historic.git

merge in some more MSSQL code, including odbc dynamic cursor support
---

diff --git a/lib/DBIx/Class/Storage/DBI/MSSQL.pm b/lib/DBIx/Class/Storage/DBI/MSSQL.pm
index fe51f1b..5bf3c10 100644
--- a/lib/DBIx/Class/Storage/DBI/MSSQL.pm
+++ b/lib/DBIx/Class/Storage/DBI/MSSQL.pm
@@ -8,6 +8,10 @@ use mro 'c3';
 
 use List::Util();
 
+__PACKAGE__->mk_group_accessors(simple => qw/
+  _identity _identity_method
+/);
+
 __PACKAGE__->sql_maker_class('DBIx::Class::SQLAHacks::MSSQL');
 
 sub insert_bulk {
@@ -78,15 +82,26 @@ sub _execute {
 
   my ($rv, $sth, @bind) = $self->dbh_do($self->can('_dbh_execute'), @_);
   if ($op eq 'insert') {
-    $self->{_scope_identity} = $sth->fetchrow_array;
-    $sth->finish;
+    $self->_identity($self->_fetch_identity($sth));
   }
 
   return wantarray ? ($rv, $sth, @bind) : $rv;
 }
 
+sub _fetch_identity {
+  my ($self, $sth) = @_;
+  my ($identity) = $sth->fetchrow_array;
+  $sth->finish;
+
+  if ((not defined $identity) && $self->_identity_method &&
+        $self->_identity_method eq '@@identity') {
+    ($identity) = $self->_dbh->selectrow_array('select @@identity');
+  }
+
+  return $identity;
+}
 
-sub last_insert_id { shift->{_scope_identity} }
+sub last_insert_id { shift->_identity }
 
 sub build_datetime_parser {
   my $self = shift;
@@ -131,6 +146,13 @@ be called is the same execute statement, not just the same connection.
 So, this implementation appends a SELECT SCOPE_IDENTITY() statement
 onto each INSERT to accommodate that requirement.
 
+C<SELECT @@IDENTITY> can also be used by issuing:
+
+  $self->_identity_method('@@identity');
+
+this is more dangerous, as inserting into a table with an on insert trigger that
+inserts into another table with an identity will give erroneous results.
+
 =head1 AUTHOR
 
 See L<DBIx::Class/CONTRIBUTORS>.
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 7e495c9..6676bfb 100644
--- a/lib/DBIx/Class/Storage/DBI/ODBC/Microsoft_SQL_Server.pm
+++ b/lib/DBIx/Class/Storage/DBI/ODBC/Microsoft_SQL_Server.pm
@@ -5,9 +5,13 @@ use warnings;
 use base qw/DBIx::Class::Storage::DBI::MSSQL/;
 use mro 'c3';
 
-1;
+use Carp::Clan qw/^DBIx::Class/;
+use List::Util();
+use Scalar::Util ();
 
-__END__
+__PACKAGE__->mk_group_accessors(simple => qw/
+  _using_dynamic_cursors
+/);
 
 =head1 NAME
 
@@ -23,6 +27,136 @@ MSSQL back-end.
 Most of the functionality is provided from the superclass
 L<DBIx::Class::Storage::DBI::MSSQL>.
 
+=head1 MULTIPLE ACTIVE STATEMENTS
+
+The following options are alternative ways to enable concurrent executing
+statement support. Each has its own advantages and drawbacks.
+
+=head2 connect_call_use_dynamic_cursors
+
+Use as:
+
+  on_connect_call => 'use_dynamic_cursors'
+
+in your L<DBIx::Class::Storage::DBI/connect_info> as one way to enable multiple
+concurrent statements.
+
+Will add C<< odbc_cursortype => 2 >> to your DBI connection attributes. See
+L<DBD::ODBC/odbc_cursortype> for more information.
+
+Alternatively, you can add it yourself and dynamic cursor will be automatically
+enabled.
+
+This will not work with CODE ref connect_info's and will do nothing if you set
+C<odbc_cursortype> yourself.
+
+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.
+
+=cut
+
+sub connect_call_use_dynamic_cursors {
+  my $self = shift;
+
+  if (ref($self->_dbi_connect_info->[0]) eq 'CODE') {
+    croak 'cannot set DBI attributes on a CODE ref connect_info';
+  }
+
+  my $dbi_attrs = $self->_dbi_connect_info->[-1];
+
+  unless (ref($dbi_attrs) && Scalar::Util::reftype($dbi_attrs) eq 'HASH') {
+    $dbi_attrs = {};
+    push @{ $self->_dbi_connect_info }, $dbi_attrs;
+  }
+
+  if (not exists $dbi_attrs->{odbc_cursortype}) {
+    # turn on support for multiple concurrent statements, unless overridden
+    $dbi_attrs->{odbc_cursortype} = 2;
+    my $connected = defined $self->_dbh;
+    $self->disconnect;
+    $self->ensure_connected if $connected;
+    $self->_set_dynamic_cursors;
+  }
+}
+
+sub _set_dynamic_cursors {
+  my $self = shift;
+  $self->_using_dynamic_cursors(1);
+  $self->_identity_method('@@identity');
+}
+
+sub _rebless {
+  no warnings 'uninitialized';
+  my $self = shift;
+
+  if (ref($self->_dbi_connect_info->[0]) ne 'CODE' &&
+      eval { $self->_dbi_connect_info->[-1]{odbc_cursortype} } == 2) {
+    $self->_set_dynamic_cursors;
+    return;
+  }
+
+  $self->_using_dynamic_cursors(0);
+}
+
+=head2 connect_call_use_server_cursors
+
+Use as:
+
+  on_connect_call => 'use_server_cursors'
+
+May allow multiple active select statements. See
+L<DBD::ODBC/odbc_SQL_ROWSET_SIZE> for more information.
+
+Takes an optional parameter for the value to set the attribute to, default is
+C<2>.
+
+B<WARNING>: this does not work on all versions of SQL Server, and may lock up
+your database!
+
+=cut
+
+sub connect_call_use_server_cursors {
+  my $self            = shift;
+  my $sql_rowset_size = shift || 2;
+
+  $self->_dbh->{odbc_SQL_ROWSET_SIZE} = $sql_rowset_size;
+}
+
+=head2 connect_call_use_mars
+
+Use as:
+
+  on_connect_call => 'use_mars'
+
+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.
+
+B<WARNING>: This has implications for the way transactions are handled.
+
+=cut
+
+sub connect_call_use_mars {
+  my $self = shift;
+
+  my $dsn = $self->_dbi_connect_info->[0];
+
+  if (ref($dsn) eq 'CODE') {
+    croak 'cannot change the DBI DSN on a CODE ref connect_info';
+  }
+
+  if ($dsn !~ /MARS_Connection=/) {
+    $self->_dbi_connect_info->[0] = "$dsn;MARS_Connection=Yes";
+    my $connected = defined $self->_dbh;
+    $self->disconnect;
+    $self->ensure_connected if $connected;
+  }
+}
+
+1;
+
 =head1 AUTHOR
 
 See L<DBIx::Class/CONTRIBUTORS>.
diff --git a/t/746mssql.t b/t/746mssql.t
index fa8f137..e5be28a 100644
--- a/t/746mssql.t
+++ b/t/746mssql.t
@@ -12,7 +12,7 @@ my ($dsn, $user, $pass) = @ENV{map { "DBICTEST_MSSQL_ODBC_${_}" } qw/DSN USER PA
 plan skip_all => 'Set $ENV{DBICTEST_MSSQL_ODBC_DSN}, _USER and _PASS to run this test'
   unless ($dsn && $user);
 
-plan tests => 33;
+plan tests => 34;
 
 my $schema = DBICTest::Schema->connect($dsn, $user, $pass);
 
@@ -48,12 +48,22 @@ SQL
 
 my %seen_id;
 
-# fresh $schema so we start unconnected
-$schema = DBICTest::Schema->connect($dsn, $user, $pass);
+my @opts = (
+  { on_connect_call => 'use_dynamic_cursors' },
+  {},
+);
+my $new;
 
-# test primary key handling
-my $new = $schema->resultset('Artist')->create({ name => 'foo' });
-ok($new->artistid > 0, "Auto-PK worked");
+# test Auto-PK with different options
+for my $opts (@opts) {
+  $schema = DBICTest::Schema->clone;
+  $schema->connection($dsn, $user, $pass, $opts);
+
+  $schema->resultset('Artist')->search({ name => 'foo' })->delete;
+
+  $new = $schema->resultset('Artist')->create({ name => 'foo' });
+  ok($new->artistid > 0, "Auto-PK worked");
+}
 
 $seen_id{$new->artistid}++;