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

Hello monks,

I'm trying to implement an Oracle-driven web application with Class::DBI. All is generally going well, except when I try to access the class that points to a view instead of a real table; I get errors like 
Can't locate object method "search" via package "TestPkg::View" at /ho
+me/janjan/test.pl line 33.

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I get the same error no matter what method I call, which leads me to believe that the package just isn't working.

Now, I've taken a look at Class::DBI::View, and even tried it out -- but, alas, with the same error. It was then that I delved a little deeper into Class::DBI::View, and began to think that it's possible that it doesn't support Oracle.

I'm using perl 5.005_03, Class::DBI 0.90 (I know, I know -- but political reasons keep me from upgrading DBI.pm. Ugh.), and the latest version of Class::DBI::Oracle.

All of my other packages seem to work just fine. Is there anything else I can try, short of setting up a cron job to populate a real table from the view?

Many thanks!

Replies are listed 'Best First'.
Re: Class::DBI::Oracle and views
by perrin (Chancellor) on Sep 28, 2003 at 18:24 UTC
    Class::DBI::View is for simulating views, not for working with real ones. I can't tell quite what you're doing from your post. How about showing us the code for TestPkg::View and the script you called it from?
[reply]
      Sure, and thank you. Here's test.pl: 
      #!/usr/bin/perl -w
use strict;

require Modules.pl;

my @students = TestPkg::View->retrieve_all;
# returns the same error as search() would
warn Dumper(\@students);

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      And here's code from Modules.pl -- I'm not using Class::DBI::View in this version of the code, obviously. (Relevant info: this is a view containing enrollment data for a course.) 
      package TestPkg::DBI;
use base 'Class::DBI::Oracle'; 
TestPkg::DBI->set_db('Main', 'dbi:Oracle:devdv', 'username', 'password
+');

package TestPkg::View;
use base TestPkg::DBI;
__PACKAGE__->table('course_enrollment');
__PACKAGE__->columns( All => qw/id username year term name_first name_
+last/ );

# and just for kicks, here's another package that's working just fine
# it points to a table, not a view
package TestPkg::Permissions;
use base TestPkg::DBI;
__PACKAGE__->table('permissions');
__PACKAGE__->columns( All => qw/id student_id access_level/);

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      The view is just generated from a command like 
      CREATE OR REPLACE VIEW course_enrollment
AS SELECT [...]

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      (it's of course much longer and nastier -- but I can select things from it on the command line just fine.)
[reply]
[d/l]
[select]
        Well, I don't see anything wrong here. It's probably a bad idea to keep all of your packages in Modules.pl (as opposed to separate files) and there is no reason to use Class::DBI::Oracle if you're not using the set_up_table call, but neither of those should break it.

        Can you access this view from DBI when you don't go through Class::DBI?

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