debian man page for data::printer::filter::db

Data::Printer::Filter::DB(3pm)				User Contributed Perl Documentation			    Data::Printer::Filter::DB(3pm)

NAME
       Data::Printer::Filter::DB - pretty printing database objects

SYNOPSIS
       In your program:

	 use Data::Printer filters => {
	     -external => [ 'DB' ],
	 };

       or, in your ".dataprinter" file:

	 {
	   filters => {
	     -external => [ 'DB' ],
	 };

DESCRIPTION
       This is a filter plugin for Data::Printer. It filters through DBI's handlers (dbh) and statement (sth) objects displaying relevant
       information for the user.

       DBI is an extremely powerful and complete database interface. But it does a lot of magic under the hood, making their objects somewhat
       harder to debug. This filter aims to fix that :)

       For instance, say you want to debug something like this:

	 use DBI;
	 my $dbh = DBI->connect('dbi:DBM(RaiseError=1):', undef, undef );

       A regular Data::Dumper output gives you absolutely nothing:

       $VAR1 = bless( {}, 'DBI::db' );

       Data::Printer makes it better, but only to debug the class itself, not helpful at all to see its contents and debug your own code:

	   DBI::db  {
	       Parents	     DBI::common
	       Linear @ISA   DBI::db, DBI::common
	       public methods(48) : begin_work, clone, column_info, commit, connected, data_sources, disconnect, do, foreign_key_info, get_info, last_insert_id, ping, prepare, prepare_cached, preparse, primary_key, primary_key_info, quote, quote_identifier, rollback, rows, selectall_arrayref, selectall_hashref, selectcol_arrayref, selectrow_array, selectrow_arrayref, selectrow_hashref, sqlite_backup_from_file, sqlite_backup_to_file, sqlite_busy_timeout, sqlite_collation_needed, sqlite_commit_hook, sqlite_create_aggregate, sqlite_create_collation, sqlite_create_function, sqlite_enable_load_extension, sqlite_last_insert_rowid, sqlite_progress_handler, sqlite_register_fts3_perl_tokenizer, sqlite_rollback_hook, sqlite_set_authorizer, sqlite_update_hook, statistics_info, table_info, tables, take_imp_data, type_info, type_info_all
	       private methods(0)
	       internals: {
	       }
	   }

       Fear no more! If you use this filter, here's what you'll see:

	   SQLite Database Handle (connected) {
	       dbname: file.db
	       Auto Commit: 1
	       Statement Handles: 0
	       Last Statement: -
	   }

       Much better, huh? :)

       Statement handlers are even better. Imagine you continued your code with something like:

	 my $sth = $dbh->prepare('SELECT * FROM foo WHERE bar = ?');
	 $sth->execute(42);

       With this filter, instead of an empty dump or full method information, you'll get exactly what you came for:

	SELECT * FROM foo WHERE bar = ?  (42)

       Note that if your driver does not support holding of parameter values, you'll get a "bindings unavailable" message instead of the bound
       values.

SEE ALSO
       Data::Printer

perl v5.14.2							    2011-05-30					    Data::Printer::Filter::DB(3pm)