my $data_source = 'DBI:mysql:'.
         $self->config_param('mysql.database').':'.
         $self->config_param('mysql.host');

##</code><code>##

    my $data_source = 'DBI:mysql:database='.
         $self->config_param('mysql.database').';host='.
         $self->config_param('mysql.host');

##</code><code>##

    my $data_source = sprintf 'DBI:mysql:database=%s;host=%s',
        $self->config_param('mysql.database'),
        $self->config_param('mysql.host');