my $dbh = DBI->connect( $whatever… )
...
my $sth = $dbh->prepare( "select field from table where id != ?" );
$sth->execute( '$in{cid}' );  # an 8-character string is the placeholder value
...

##</code><code>##

my %in;
$in{cid} = "something";

my $dbh = DBI->connect( $whatever… )
...
my $sth = $dbh->prepare( "select field from table where id != ?" );
$sth->execute( $in{cid} );  # the hash element value is the placeholder value
...