um, too much typing, it goes like this

sub prepex {
    my( $sql, @bindvalues ) = @_;
    my $row;
    eval {
       $row = $dbh->selectrow_arrayref( $sql, {}, @bindvalues );;
       1;
    } or do {
        writeerr( $@ );
        ...;
    };
    return $row->[0] unless wantarray;
    return @$row;
}
[download]

RaiseError tells you (via $@ )whether prepare or execute or fetch failed

If you want the number of rows selected, COUNT(), like

SELECT
    COUNT(*)
FROM
    data
WHERE
    skey='Stuff'
[download]

or using placeholders/bindvalues

prepex(
    q{
        SELECT
            COUNT(*)
        FROM
            data
        WHERE
            skey=? 
    },
    'Stuff',
);
[download]

see also this and DBI recipes