[Dbix-class] Newbie question about relations

[Dave Howorth]

Diego M. Vadell wrote:
> Hi,
>   I am just starting with DBIx::Class and Catalyst, and quite frankly I don't 
> know much about designing the tables. I decided to start exploring Catalyst 
> by making a simple file server via web, with sqlite tables:
> 
> CREATE TABLE Files (
>             id          INTEGER PRIMARY KEY,
>             filename       TEXT
>     );
> 
>     CREATE TABLE Perms (
>             file_id     INTEGER,
>             user_id     INTEGER,
>             read        BOOLEAN,
>             del         BOOLEAN,
>             new         BOOLEAN,
>             PRIMARY KEY (file_id, user_id)
>     );
>     CREATE TABLE Users (
>             id          INTEGER PRIMARY KEY,
>             username    TEXT,
>             password    TEXT
>     );
> 
> The idea is that the "Files" tables has a filename, the "Users" have username 
> and password and "Perms" have the ACL of every file wrt every user. I can 
> $schema->populate Files and Users, but when I try to do it with Perms, I get:
> 
> Can't use string ("WFSDB::Perms") as a HASH ref while "strict refs" in use 
> at /usr/lib/perl5/site_perl/5.8.5/DBIx/Class/InflateColumn.pm line 168.

Just yesterday, I got this error:

  Can't use string ("DBSchema::EntryAttributes") as a HASH ref
  while "strict refs" in use at
  /usr/lib/perl5/site_perl/5.8.6/DBIx/Class/InflateColumn.pm line 168.

The good news for me, and perhaps you, is that I know what caused my error!

This error is DBIC's oh-so-subtle way of telling me that I have a column
name in my database that conflicts with a DBIC method name. In my case,
I happen to know it is 'belongs_to'.

To find out if this is the case for you, run your script in the debugger
and look at the stack backtrace you get when it dies. For me, the name
of the column is in the second level down, like this:

  DBIx::Class::InflateColumn::get_column('DBSchema::EntryAttributes',
  'belongs_to') called at
  /usr/lib/perl5/site_perl/5.8.6/DBIx/Class/Row.pm line 241

HTH, Dave