There are ways to do this but it is generally considered bad practice to do so unless you have no other choice. Consider instead an array.

$lines[0] = "use pricedb";
$lines[1] = "second statement";

for my $sql (@lines) {
   $dbh->do($sql);
   # check code here
}
[download]

That easily lends itself to pulling queries from a file or building queries programmatically. It also means you can have an arbitrary number of lines. I highly suggest getting
Learning Perl
And/Or
The Camel Book
If you are going to be doing any amount of Perl programming, both are very useful. Of course there are lots of online tutorials, too.