From 9367bd61a6b29ad9b0dbb083d094a1c1818d10c5 Mon Sep 17 00:00:00 2001
From: Kenichi Ishigaki <ishigaki@cpan.org>
Date: Thu, 20 Oct 2011 16:16:17 +0000
Subject: [PATCH] explained finish and rollback issue

---
 lib/DBD/SQLite.pm | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/lib/DBD/SQLite.pm b/lib/DBD/SQLite.pm
index 094b588..a105d60 100644
--- a/lib/DBD/SQLite.pm
+++ b/lib/DBD/SQLite.pm
@@ -952,6 +952,34 @@ Note that this works only when all of the connections use the same
 (non-deferred) transaction. See L<http://sqlite.org/lockingv3.html>
 for locking details.
 
+=head2 C<< $sth->finish >> and Transaction Rollback
+
+As the L<DBI> doc says, you almost certainly do B<not> need to
+call L<DBI/finish> method if you fetch all rows (probably in a loop).
+However, there are several exceptions to this rule, and rolling-back
+of an unfinished C<SELECT> statement is one of such exceptional
+cases. 
+
+SQLite prohibits C<ROLLBACK> of unfinished C<SELECT> statements in
+a transaction (See L<http://sqlite.org/lang_transaction.html> for
+details). So you need to call C<finish> before you issue a rollback.
+
+  $sth = $dbh->prepare("SELECT * FROM t");
+  $dbh->begin_work;
+  eval {
+      $sth->execute;
+      $row = $sth->fetch;
+      ...
+      die "For some reason";
+      ...
+  };
+  if($@) {
+     $sth->finish;  # You need this for SQLite
+     $dbh->rollback;
+  } else {
+     $dbh->commit;
+  }
+
 =head2 Processing Multiple Statements At A Time
 
 L<DBI>'s statement handle is not supposed to process multiple