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perl xml format question

by lukka1 (Initiate)
on Jan 28, 2013 at 16:31 UTC ( #1015728=perlquestion: print w/replies, xml ) Need Help??
lukka1 has asked for the wisdom of the Perl Monks concerning the following question:

Hi experts,

I need to read a few columns from a database table and write out the result in a specified xml format.

For e.g say the table (called SKU) has the following data

#ITEM, LOC--->column headers

011-5000, DLSDC

011-5100, FRMNT

I need this to be written out in the following xml-format in a file say sku.xml. Since i did not know how the xml-formatting would come out in this message, i enclosed the desired/actual xml-format within code tags (though this is not actually code)



<metadata> <field name="ITEM" alias="a1"/> <field name="LOC" alias="a2"/> </metadata> <data> <rec> <a1>011-5000</a1> <a2>DLSDC</a2> </rec> <rec> <a1>011-5100</a1> <a2>FRMNT</a2> </rec> </data>

I tried the following code to write this out in xml format. (since i am a newbie, i tried to search the perl monks/google repository and did a cut/paste of an example using modules like DBI; XML::Generator::DBI; XML::Handler::YAWriter; as follows. But this obviously gives me an output using the standard xml format (which is different from the desired output)

use strict; use DBI; use XML::Generator::DBI; use XML::Handler::YAWriter; my $dbh = DBI->connect ("dbi:Oracle:host=myhostname;sid=mysid;port=152 +1", "userid", "pwd", { RaiseError => 0, AutoCommit => 0,ora_envhp=> 0}); my $out = XML::Handler::YAWriter->new (AsFile => "sku.xml"); my $gen = XML::Generator::DBI->new ( Handler => $out, dbh => $dbh, Indent => 1 ); $gen->execute ("SELECT ITEM,LOC FROM SKU"); $dbh->disconnect ();

The actual output i get using the above script is as follows



<?xml version="1.0" encoding="UTF-8"?><database> <select> <row> <ITEM>011-5000</ITEM> <LOC>DLSDC</LOC> </row> <row> <ITEM>011-5100</ITEM> <LOC>FRMNT</LOC> </row> <row> </select> </database>

Can you point out what i need to do to get the output in the desired xml format. Are there some easy ways to get this done? (e.g. some other modules i need to use which give output using an aliased xml output similar to the desired output)?

Thank you in advance

Replies are listed 'Best First'.
Re: perl xml format question
by tobyink (Abbot) on Jan 28, 2013 at 17:14 UTC
    use strict; use warnings; use DBI; use XML::LibXML 2; use XML::LibXML::PrettyPrint qw(print_xml); my $dbh = DBI->connect("dbi:SQLite:dbname=:memory:","",""); # Create demo data... $dbh->do("CREATE TABLE sku (item text, loc text)"); $dbh->do("INSERT INTO sku VALUES ('011-5000', 'DLSDC')"); $dbh->do("INSERT INTO sku VALUES ('011-5100', 'FRMNT')"); my $xml = XML::LibXML::Document->new(); my $root = XML::LibXML::Element->new('results'); $xml->setDocumentElement($root); my $metadata = $root->addNewChild(undef, 'metadata'); my $data = $root->addNewChild(undef, 'data'); my $sth = $dbh->prepare("SELECT * FROM sku"); my $meta_done = 0; # false $sth->execute; while (my @row = $sth->fetchrow_array) { unless ($meta_done) { my $alias_num = 0; for my $col (@{$sth->{NAME_uc}}) { my $field = $metadata->addNewChild(undef, 'field'); %$field = ( name => $col, alias => "a".++$alias_num, ); } $meta_done = 1; } my $rec = $data->addNewChild(undef, 'rec'); for my $i (1 .. @row) { $rec->addNewChild(undef, "a$i")->appendText($row[$i-1]); } } my $pretty = XML::LibXML::PrettyPrint->new( element => { compact => sub { ($_[0]->localname||'') =~ /^a[0-9]+$ +/ } }, ); $pretty->pretty_print($xml); print $xml->toString;
    package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

      Hi Tobyink, Thank you for your super-prompt and helpful response. I was getting the following error when i tried to use the code

      my $field = $metadata->addNewChild(undef, 'field'); %$field = ( name => $col, alias => "a".++$alias_num, );

      I got the error "Not a HASH reference at line 52". Any idea what i need to change to avoid this error

      I also got the following error "Issuing rollback() due to DESTROY without explicit disconnect() of DBD::Oracle::db handle (DESCRIPTION=(ADDRESS=(HOST=IN1NPDVMPMT02)(PROTOCOL=tcp)(PORT=1521))"

        Are you using an oldish version of XML::LibXML perhaps?

        The ability to handle an element's attributes like a hash was only added in 1.91 IIRC.

        You can use setAttribute in older versions.

        package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

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