select m, p from ... where u = N group by m, p order by m, p;
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my( $m, $p );
$cursor->bind_col( 1, \$m );
$cursor->bind_col( 2, \$p, { type => SQL_INTEGER } );
my @data;
while(  $cursor->fetch()  ) {
    if(   @data  &&  $m == $data[-1][0]  ) {
        push @{ $data[-1][1] }, 0+$p;
    } else {
        push @data, [ $m, [0+$p] ];
    }
}
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