.\" Automatically generated by Pod::Man 2.28 (Pod::Simple 3.29)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings.  \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is turned on, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{
.    if \nF \{
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\" ========================================================================
.\"
.IX Title "Data::Printer::Filter::DB 3pm"
.TH Data::Printer::Filter::DB 3pm "2016-04-27" "perl v5.22.1" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
Data::Printer::Filter::DB \- pretty printing database objects
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
In your program:
.PP
.Vb 3
\&  use Data::Printer filters => {
\&      \-external => [ \*(AqDB\*(Aq ],
\&  };
.Ve
.PP
or, in your \f(CW\*(C`.dataprinter\*(C'\fR file:
.PP
.Vb 5
\&  {
\&    filters => {
\&      \-external => [ \*(AqDB\*(Aq ],
\&    },
\&  };
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This is a filter plugin for Data::Printer. It filters through \s-1DBI\s0's
handlers (dbh) and statement (sth) objects displaying relevant information for
the user.  It also filters any object which inherits from
DBIx::Class::Schema, DBIx::Class::ResultSet or
DBIx::Class::ResultSetColumn.
.SS "\s-1DBI\s0 Sample Output"
.IX Subsection "DBI Sample Output"
\&\s-1DBI\s0 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 :)
.PP
For instance, say you want to debug something like this:
.PP
.Vb 2
\&  use DBI;
\&  my $dbh = DBI\->connect(\*(Aqdbi:DBM(RaiseError=1):\*(Aq, undef, undef );
.Ve
.PP
A regular Data::Dumper output gives you absolutely nothing:
.PP
\&\f(CW$VAR1\fR = bless( {}, 'DBI::db' );
.PP
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:
.PP
.Vb 8
\&    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: {
\&        }
\&    }
.Ve
.PP
Fear no more! If you use this filter, here's what you'll see:
.PP
.Vb 6
\&    SQLite Database Handle (connected) {
\&        dbname: file.db
\&        Auto Commit: 1
\&        Statement Handles: 0
\&        Last Statement: \-
\&    }
.Ve
.PP
Much better, huh? :)
.PP
Statement handlers are even better. Imagine you continued your code with something like:
.PP
.Vb 2
\&  my $sth = $dbh\->prepare(\*(AqSELECT * FROM foo WHERE bar = ?\*(Aq);
\&  $sth\->execute(42);
.Ve
.PP
With this filter, instead of an empty dump or full method information, you'll get
exactly what you came for:
.PP
.Vb 1
\& SELECT * FROM foo WHERE bar = ?  (42)
.Ve
.PP
Note that if your driver does not support holding of parameter values, you'll get a
\&\f(CW\*(C`bindings unavailable\*(C'\fR message instead of the bound values.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
Data::Printer, Data::Printer::Filter