Different types of prepare statements

From: Robert (catcher_at_linuxmail.org)
Date: 07/29/04 

To: dbi-users@perl.org
Date: Thu, 29 Jul 2004 11:51:29 -0400

I have seen:

my $sth = $dbh->prepare( <<SQL_END );
SELECT blah
FROM blah
WHERE blah = blah
SQL_END

my $sth = $dbh->prepare(q{
SELECT blah
FROM blah
WHERE blah = blah
});

my $sth = $dbh->prepare(qq{
SELECT blah
FROM blah
WHERE blah = blah
});

What is the difference? I am new to Perl/DBI stuff.

Robert