From: Rafael Kitover <rkitover@cpan.org>
Date: Sat, 25 Jul 2009 19:23:49 +0000 (+0000)
Subject: make insert work as a nested transaction too
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=f6de71113251acc964444e57bf3d38a23dc09ffd;p=dbsrgits%2FDBIx-Class-Historic.git

make insert work as a nested transaction too
---

diff --git a/lib/DBIx/Class/Storage/DBI/Sybase.pm b/lib/DBIx/Class/Storage/DBI/Sybase.pm
index 6460a3c..b320242 100644
--- a/lib/DBIx/Class/Storage/DBI/Sybase.pm
+++ b/lib/DBIx/Class/Storage/DBI/Sybase.pm
@@ -32,7 +32,7 @@ will be reblessed to L<DBIx::Class::Storage::DBI::Sybase::NoBindVars>. You can
 also enable that driver explicitly, see the documentation for more details.
 
 With this driver there is unfortunately no way to get the C<last_insert_id>
-without doing a C<select max(col)>.
+without doing a C<SELECT MAX(col)>.
 
 But your queries will be cached.
 
@@ -95,6 +95,14 @@ EOF
   }
 }
 
+# Make sure we have CHAINED mode turned on, we don't know how DBD::Sybase was
+# compiled.
+sub _populate_dbh {
+  my $self = shift;
+  $self->next::method(@_);
+  $self->_dbh->{syb_chained_txn} = 1;
+}
+
 sub _using_freetds {
   my $self = shift;
 
@@ -199,12 +207,9 @@ List::Util::first { $bind_info->{$_}{is_auto_increment} } (keys %$bind_info);
     }
 
     if ($identity_col) {
-# Sybase has nested transactions, only the outermost is actually committed
       $sql =
-        "BEGIN TRANSACTION\n" .
         "$sql\n" .
-        $self->_fetch_identity_sql($ident, $identity_col) . "\n" .
-        "COMMIT";
+        $self->_fetch_identity_sql($ident, $identity_col) . "\n";
     }
   }
 
@@ -233,14 +238,24 @@ sub _execute {
 
 sub last_insert_id { shift->_identity }
 
-# override to handle TEXT/IMAGE
+# override to handle TEXT/IMAGE and nested txn
 sub insert {
   my ($self, $source, $to_insert) = splice @_, 0, 3;
   my $dbh = $self->_dbh;
 
   my $blob_cols = $self->_remove_blob_cols($source, $to_insert);
 
-  my $updated_cols = $self->next::method($source, $to_insert, @_);
+# Sybase has nested transactions fortunately, because we have to do the insert
+# in a transaction to avoid race conditions with the SELECT MAX(COL) identity
+# method used when placeholders are enabled.
+  my $updated_cols = do {
+    local $self->{auto_savepoint} = 1;
+    my $args = \@_;
+    my $method = $self->next::can;
+    $self->txn_do(
+      sub { $self->$method($source, $to_insert, @$args) }
+    );
+  };
 
   $self->_insert_blobs($source, $blob_cols, $to_insert) if %$blob_cols;
 
diff --git a/lib/DBIx/Class/Storage/DBI/Sybase/Base.pm b/lib/DBIx/Class/Storage/DBI/Sybase/Base.pm
index be57610..af2a98f 100644
--- a/lib/DBIx/Class/Storage/DBI/Sybase/Base.pm
+++ b/lib/DBIx/Class/Storage/DBI/Sybase/Base.pm
@@ -27,6 +27,19 @@ sub _ping {
   return $@ ? 0 : 1;
 }
 
+sub _placeholders_supported {
+  my $self = shift;
+  my $dbh  = $self->_dbh;
+
+  return eval {
+# There's also $dbh->{syb_dynamic_supported} but it can be inaccurate for this
+# purpose.
+    local $dbh->{PrintError} = 0;
+# this specifically tests a bind that is NOT a string
+    $dbh->selectrow_array('select 1 where 1 = ?', {}, 1);
+  };
+}
+
 1;
 
 =head1 AUTHORS
diff --git a/t/746sybase.t b/t/746sybase.t
index 7c9e56b..6d77b4e 100644
--- a/t/746sybase.t
+++ b/t/746sybase.t
@@ -76,6 +76,9 @@ SQL
 # so we start unconnected
   $schema->storage->disconnect;
 
+# inserts happen in a txn, so we test txn nesting
+  $schema->txn_begin;
+
 # test primary key handling
   my $new = $schema->resultset('Artist')->create({ name => 'foo' });
   ok($new->artistid > 0, "Auto-PK worked");
@@ -88,6 +91,8 @@ SQL
     $seen_id{$new->artistid}++;
   }
 
+  $schema->txn_commit;
+
 # test simple count
   is ($schema->resultset('Artist')->count, 7, 'count(*) of whole table ok');