NAME

CGI::Application::Plugin::DBH - Easy DBI access from CGI::Application

SYNOPSIS

 use CGI::Application::Plugin::DBH (qw/dbh_config dbh/);

 sub cgiapp_init  {
    my $self = shift;

    # use the same args as DBI->connect();
    $self->dbh_config($data_source, $username, $auth, \%attr);

    # or to use more than one dbh
    $self->dbh_config('my_handle', 
                    [ $data_source, $user, $auth, \%attr ]);
    $self->dbh_config('my_other_handle', 
                    [ $data_source, $user, $auth, \%attr ]);
 }

 sub my_run_mode {
    my $self = shift;

    my $date = $self->dbh->selectrow_array("SELECT CURRENT_DATE");
    # again with a named handle
    $date = $self->dbh('my_handle')->selectrow_array("SELECT CURRENT_DATE");

    # OR ...

    my $dbh = $self->dbh;
    # again with a named handle
    $dbh = $self->dbh('my_other_handle');
    my $date = $dbh->selectrow_array("SELECT CURRENT_DATE");
 } 

DESCRIPTION

CGI::Application::Plugin::DBH adds easy access to a DBI database handle to your CGI::Application modules. Lazy loading is used to prevent a database connection from being made if the dbh method is not called during the request. In other words, the database connection is not created until it is actually needed.

METHODS

dbh()

 my $date = $self->dbh->selectrow_array("SELECT CURRENT_DATE");
 # again with a named handle
 $date = $self->dbh('my_handle')->selectrow_array("SELECT CURRENT_DATE");

 # OR ...

 my $dbh = $self->dbh;
 # again with a named handle
 $dbh = $self->dbh('my_other_handle');
 my $date = $dbh->selectrow_array("SELECT CURRENT_DATE");

This method will return the current DBI database handle. The database handle is created on the first call to this method, and any subsequent calls will return the same handle.

dbh_config()

 sub cgiapp_init  {
    my $self = shift;

    # use the same args as DBI->connect();
    $self->dbh_config($data_source, $username, $auth, \%attr);

    # or to use more than one dbh
    $self->dbh_config('my_handle', 
                    [ $data_source, $user, $auth, \%attr ]);
    $self->dbh_config('my_other_handle', 
                    [ $data_source, $user, $auth, \%attr ]);

    # ...or use some existing handle you have
    $self->dbh_config($DBH);
    $self->dbh_config('my_handle', $DBH);   # this works too
 }

Used to provide your DBI connection parameters. You can either pass in an existing DBI database handle, or provide the usual parameters used for DBI->connect().

The recommended place to call dbh_config is in the cgiapp_init stage of CGI::Application. If this method is called after the database handle has already been accessed, then it will die with an error message.

dbh_default_name()

 sub my_runmode {
    my $self = shift;

    my $old_handle_name = $self->dbh_default_name('my_handle');
    $self->some_legacy_code();  # some_legacy_code() will get "my_handle"
                                # when it calls $self->dbh() without parameters

    $self->dbh_default_name($old_handle_name);    # Return to normal.
 }

Can be used to alter the name of the handle that is returned by dbh() when called with no parameters. It can even be used to alter the name used for the unamed handle if called before dbh_config().

Using this method is completely optional. If you don't have a use for it don't use it. Internally the handle name "__cgi_application_plugin_dbh" is used to keep track of the unnamed handle unless it is changed by dbh_default_name() before a call to dbh_config() without a name parameter.

SEE ALSO

Ima::DBI is similar, but has much more complexity and features.

CGI::Application, DBI, CGI::Application::Plugin::ValidateRM, perl(1)

AUTHOR

Mark Stosberg <mark@summersault.com>

Multi Handle Support added by: Tony Fraser <tony@sybaspace.com>

LICENSE

Copyright (C) 2004 Mark Stosberg <mark@summersault.com>

This library is free software. You can modify and or distribute it under the same terms as Perl itself.