my $bazfind = shift || "12";

print "Looking for $bazfind.\n";

my $dbh=DBI->connect($SID, $user, $pass, {AutoCommit=>1}) 
  or die "Could not connect to $SID: $DBI::errstr\n";

my $FOOBAR_SQL = "SELECT FOO FROM BARVILLE WHERE BAZ=?";

my $sth=$dbh->prepare($FOOBAR_SQL) 
  or die "Could not prepare $FOOBAR_SQL: $DBI::errstr\n";

$sth->execute($bazfind)
  or die qq!Could not execute $FOOBAR_SQL with "$bazfind": $DBI::errstr\n!;

...etc. etc.