Brother monks, I seek your wisdom.

I am trying to write a DBIx::Class based script that runs queries on a table in a MySQL database where the name of the table is not known till runtime. The the table definition (the columns and their types) is known beforehand.

I thought I could just make use of the __PACKAGE__->table('some_name'); hook defined in DBIx::Class::Table, to set the name of the table at runtime, but that does not work. I wrote:

package MyCompany::Schema::LogEntry;
use base 'DBIx::Class::Core';
__PACKAGE__->add_columns(
    'id'          => { data_type=>'int',         is_auto_increment=>1 
+},
    # Other rows. (deleted)
);
__PACKAGE__->set_primary_key('id');

[download]

My main script looks like:

use Getopt::Long;
use MyCompany::Schema::LogEntry;

GetOptions( $opts,
    'help|h','man','verbose+', 'quiet',
    'dbic_dsn=s', 'dbic_user=s', 'dbic_password=s', 'db_table=s',
) or pod2usage(-verbose=>0, -message => "incorrect options");

# Change the log table to the real one.
MyCompany::Schema::LogEntry->table( $opts->{'db_table'} );

my $log_schema  = MyCompany::Schema->connect( @{$opts}{'dbic_dsn','dbi
+c_user','dbic_password'} )

my $matching_log_RS = $log_schema->resultset('LogEntry')->search({%sea
+rchTerms});

print $matching_log_RS->as_query();

[download]

I intended to call MyCompany::Schema::LogEntry->table() at runtime, but the code above would not compile. I got the error message:

DBIx::Class::Schema::throw_exception(): Can't locate object method "re
+sult_source_instance" via package "MyCompany::Schema::LogEntry" at /u
+sr/local/lib/perl/5.10.1/DBIx/Class/ResultSourceProxy.pm line 37.

[download]

I then thought, I could give the table a dummy name, and then change it later, so I added __PACKAGE__->table('__CHANGE_ME__'); to the source just before the add_columns call.

That still did not work, as internally DBIx::Class had stored the dummy table name, and not updated to the replacement name. The query returned by $matching_log_RS->as_query(); on the last line of my main program refers to the dummy table name rather than the updated one.

Can you offer any help or assistance?

In reply to DBIx::Class - Define a table name at runtime by chrestomanci

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