DBIx::Class "Can't call method 'select' on an undefined value"

sundialsvc4 has asked for the wisdom of the Perl Monks concerning the following question:

Okay, let me start over on this post... :-)

The code looks like this:

my $schema = My::Schema::Class->connect
("dbi:mysql:dbname=BLAHBLAH;host=localhost", 
"BLAH", "HEAPBIGSECRET", {AutoCommit => 1})
or croak("cannot connect to main database");
    
# Strobe the database-connection right now to be sure it's here
$schema->storage->ensure_connected();
croak("connection failed to main database") 
unless $schema->storage->connected;
[download]

So far so good... but now, in my test-script...

lives_ok { require My::Schema::Class::TFoodtype}    
   "required OK";
lives_ok { My::Schema::Class->load_classes(qw/TFoodtype/) }  
   "loaded one again";
isa_ok($s->schema->resultset('TFoodtype'),
  "DBIx::Class::ResultSet");
[download]

And this is what fails:

my @records;
lives_ok { @records = $s->schema
   ->resultset('TFoodtype')
   ->search({foodtype=>'YUM'})->all()
         } "searched okay";
[download]

This is what it says:

Can't call method "select" on an undefined value at 
(..blah..)/5.8.8/DBIx/Class/ResultSet.pm line 514.
[download]

Now, if you study the test-script closely (it uses Test::More and Test::Except ...), you will see that I am trying to systematically check everything I can think of. I know, by this point, that the connection is present. I know that the class is loaded. I know that the resultset('TFoodtype') call is returning a result-set. So it comes down to the final call... and I know that I am doing something abjectly stupid here and I just can't see it!

(Whimper...) My hand is poised, ready to slap my forehead...

Replies are listed 'Best First'.
Re: DBIx::Class "Can't call method 'select' on an undefined value" by Your Mother (Archbishop) on Jan 22, 2009 at 01:06 UTC
This is mostly guesswork so take it with a grain of salt but it looks like your test is not where your error is. That select error is related to calling ->cursor. Are you using DBIC cursors in there somewhere...? Your storage is apparently getting undefined/lost somewhere in any case. You could insert a test for that and move it back until you find the trigger.	[reply]
Re: DBIx::Class "Can't call method 'select' on an undefined value" by sundialsvc4 (Abbot) on Jan 22, 2009 at 01:07 UTC
Looking further, the test: `is($rs->result_source->schema, $s->schema, "belongs to the same schema");` [download] Fails with the message: `# Failed test 'belongs to the same schema' # at t/0200_db/0200_dbconnect.t line 52. # got: 'My::Schema::Class' # expected: 'My::Schema::Class=HASH(0x8a163c4)'` [download] It appears to be saying that one is a string and the other is a hash... And indeed, $rs->result_source->storage is undefined.
Re: DBIx::Class "Can't call method 'select' on an undefined value" by sundialsvc4 (Abbot) on Jan 22, 2009 at 01:57 UTC
And doing `load_classes` in the schema base-file “magically” fixes it. Not good enough for me... I wanna understand this.
Re^2: DBIx::Class "Can't call method 'select' on an undefined value" by dragonchild (Archbishop) on Jan 23, 2009 at 03:57 UTC
load_classes() ensures everything is hooked together properly. It's a bit of side-effect magic that mst isn't thrilled with, but at least it's (mostly) all in one place. Go talk in #dbix_class@irc.perl.org if you really want to understand more. My criteria for good software: Does it work? Can someone else come in, make a change, and be reasonably certain no bugs were introduced?	[reply]
Re: DBIx::Class "Can't call method 'select' on an undefined value" by jasonk (Parson) on Jan 22, 2009 at 02:31 UTC
What is `$s`? I would suspect that `$s->schema` is returning something other than the `$schema` object, like maybe the schema class name? www.jasonkohles.com We're not surrounded, we're in a target-rich environment!	[reply] [d/l] [select]


go ahead... be a heretic
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