DBIx::ContextualFetch trouble

[prev] [thread] [next] [Date index for 2004/12/27]

Hi,

As I reported earlier in

http://groups.kasei.com/mail/arc/cdbi-talk/2004-11/msg00046.html

during the test phase of DBIx::ContextualFetch on 5.8.5
(and now on 5.8.6 too) I get

Use of uninitialized value in subroutine entry at
DBIx-ContextualFetch-1.01/blib/lib/DBIx/ContextualFetch.pm line 51.

It started to really bother me now as I get similar warnings while I am
using CDBI. Before attacking the code of CDBI I tried to look at the test 
suit of DBIx::ContextualFetch.

The first thing I got stuck with is that I don't understand this sub 
in the test code:

sub make_sth {
   my $sql = shift;
   (my $sth = $dbh->prepare($sql))->execute;
   return $sth;
}

It does not pass anything to execute();
but during the test cases some of the SQL strings passed to the
sub contain placeholders (?). As it seems I get the above warning
exactly in those cases when the query was prepared with a placeholder
but no actual value was supplied to execute.

I changed the above function to

sub make_sth {
   my $sql = shift;
   (my $sth = $dbh->prepare($sql))->execute(@_);
   return $sth;
}

passing @_ to execute and changed the test cases to pass a parameter
to the make_sth sub. First of all I could eliminate all the warning
which looks good but:

It seems that in some cases the value passed to make_sth is used
and in other case it is not. Included a patch to the test file
that shows such cases. I'd appreciat if someone who actually understand
how this module should work would look at it.

regards
    Gabor
ps. SVK rocks


=== t/01.t
==================================================================
--- t/01.t  (revision 449)
+++ t/01.t  (local)
@@ -6,7 +6,7 @@

  BEGIN {
  	eval "use DBD::SQLite";
-	plan $@ ? (skip_all => 'needs DBD::SQLite for testing') : (tests => 17);
+	plan $@ ? (skip_all => 'needs DBD::SQLite for testing') : (tests => 30);
  }

  use File::Temp qw/tempfile/;
@@ -24,7 +24,7 @@

  sub make_sth {
  	my $sql = shift;
-	(my $sth = $dbh->prepare($sql))->execute;
+	(my $sth = $dbh->prepare($sql))->execute(@_);
  	return $sth;
  }

@@ -51,8 +51,39 @@
  	my $sth = make_sth("SELECT * FROM foo ORDER BY id");
  	my @got = $sth->fetchall;
  	is $got[1]->[1], "Barney", 'fetchall @';
+	is @got, 2, 'fetchall @ count';
  }

+{    # fetchall @
+	my $sth = make_sth("SELECT * FROM foo WHERE id > ? ORDER BY id", 0);
+	my @got = $sth->fetchall(0); # parameter irrelevant here
+	is @got, 2, 'fetchall @ count';
+}
+
+{    # fetchall @
+	my $sth = make_sth("SELECT * FROM foo WHERE id > ? ORDER BY id", 0);
+	my @got = $sth->fetchall(100); # parameter irrelevant here
+	is @got, 2, 'fetchall @ count';
+}
+
+{    # fetchall @
+	my $sth = make_sth("SELECT * FROM foo WHERE id > ? ORDER BY id", 1);
+	my @got = $sth->fetchall(0); # parameter irrelevant here
+	is @got, 1, 'fetchall @ count';
+}
+
+{    # fetchall @
+	my $sth = make_sth("SELECT * FROM foo WHERE id > ? ORDER BY id", 1);
+	my @got = $sth->fetchall(1); # parameter irrelevant here
+	is @got, 1, 'fetchall @ count';
+}
+
+{    # fetchall @
+	my $sth = make_sth("SELECT * FROM foo WHERE id > ? ORDER BY id", 2);
+	my @got = $sth->fetchall(1); # parameter irrelevant here
+	is @got, 0, 'fetchall @ count';
+}
+
  {    # fetchall $
  	my $sth = make_sth("SELECT * FROM foo ORDER BY id");
  	my $got = $sth->fetchall;
@@ -72,25 +103,44 @@
  }

  {    # select_row
-	my $sth = make_sth("SELECT * FROM foo WHERE id = ?");
+	my $sth = make_sth("SELECT * FROM foo WHERE id = ?", 1);
  	my ($id, $name) = $sth->select_row(1);
  	is $name, "Fred", "select_row";
  }

  {    # select_col
-	my $sth   = make_sth("SELECT name FROM foo where id > ? ORDER BY id");
+	my $sth   = make_sth("SELECT name FROM foo WHERE id > ? ORDER BY id", 0); # is parameter irrelevant ?
  	my @names = $sth->select_col(0);
+	is $names[0], "Fred", "select_col";
  	is $names[1], "Barney", "select_col";
+	is @names, 2, '> 0 count';
  }

+{    # select_col
+	my $sth   = make_sth("SELECT name FROM foo WHERE id > ? ORDER BY id", 0); # is parameter irrelevant ?
+	my @names = $sth->select_col(1);
+	is $names[0], "Barney", "select_col";
+	is @names, 1, '> 0 count';
+}
+
+{    # select_col
+	my $sth   = make_sth("SELECT name FROM foo WHERE id > ? ORDER BY id", 100); # is parameter irrelevant ?
+	my @names = $sth->select_col(1);
+	is $names[0], "Barney", "select_col";
+	is @names, 1, '> 1 count';
+}
+
+
  {    # select_val
-	my $sth  = make_sth("SELECT name FROM foo where id = ?");
+	my $sth  = make_sth("SELECT name FROM foo where id = ?", 1); # is parameter irrelevant ?
  	my $name = $sth->select_val(1);
  	is $name, "Fred", "select_val";
+	my $noname = $sth->select_val(2);
+	is $noname, "Barney", "select_val where id=1";
  }

  {    # Execute binding
-	my $sth = make_sth("SELECT * FROM foo WHERE id > ? ORDER BY id");
+	my $sth = $dbh->prepare("SELECT * FROM foo WHERE id > ? ORDER BY id");
  	$sth->execute([0], [ \my ($id, $name) ]);
  	$sth->fetch;
  	is $id,   1,      "bound id 1";
@@ -100,3 +150,12 @@
  	is $name, "Barney", "name = Barney";
  }

+# The warning we get when we prepare an SQL with a place holder but then execute it
+# without a parameter looks like this:
+# qr/Use of uninitialized value in subroutine entry/;
+# Probably DBIx::ContextFetch should die in such cases.
+# The warning arrives from the 
+#        _untaint_execute subroutine 
+# from the 
+#       my $ret = $sth->SUPER::execute(@_);
+# line