Re: DBI: selectrow_array() return first column when called in list context

[Tim Bunce]

On Mon, Dec 23, 2013 at 09:30:22AM +0000, mimic...@gmail.com wrote:
>    The SQL query is the same in both cases, and as can be seen, the query is 
> expected to return two columns
>    (user and perm), but selectrow_array() returns undef for the second column 
> (perm in this case).
> 
>    my ($x, $y) = $dbh->selectrow_array(qq{SELECT user,perm FROM access
>    WHERE token=\'Tt9VpStL4xADSDJQtd4AkM
>    c6cVi66Mwmr9pMcCRgO4NVJ\'})|| die
>    "Could not query database: $DBI::errstr\n";

Your code could be summarized as:

    my ($x, $y) = foo() || die "...";

Note that the "||" operator forces the foo() call to be evaluated in
scalar context, so only a single value is returned. It's evaluated
something like this:

    my ($x, $y) = ( foo() || die "..." );

If you used the "or" operator instead you'd get the expected results
because the or operator precidence is below that of the "=" operator
so it's evaluated like this:

    (my ($x, $y) = foo() ) or die "...";

Tim.