sub make_closure { 
    my ($table, $column) = @_; 
    return sub { 
        my $id = shift;
        my $dbh = sqlConnect();
        my $sth = $dbh->prepare("SELECT * FROM $table WHERE $column=?");
        $sth->execute($id); 
        my $result = $sth->fetchrow_hashref();
        $sth->finish();
        return $result; 
    };
}

local *getCustomerById = make_closure("customers", "cust_id"); 
local *getUserByUserId = make_closure("users", "user_id");