Perl and PostgreSQL escaping $

Question

I have an SQL statement executed from perl.

$my_sql = qq (
            SELECT 1 AS ....
            );

Then I do

my $sm = $dbh->prepare($my_sql);
   $sm->execute;

The issue is that my SQL has regex like this in many places.

value ~ '^[1-9][0-9]?/[1-9][0-9]?/[1-9][0-9]{3}$':

So I get errors when I execute the perl script because of these '$'.

Use of uninitialized value $' in concatenation (.) or string at
DBD::Pg::st execute failed: execute called with an unbound placeholder at

How can I avoid these errors and make the SQL statement work?

Answer 1

qq(something) is just another way to say "something" while q(something) means 'something' .

The difference between "this" and 'this' is interpolation, which is enabled only inside double quotes.

my $foo = 123;
print "<< $foo >>";  # prints << 123 >>
print '<< $foo >>';  # prints << $foo >>

So, since $ is not special symbol inside '' , just change qq to q .