$q = 'select min(capid) min, max(capid) max from cap';

$rawdata = mysqli_query($ddb, $q);

$x = mysqli_num_rows($rawdata);
echo "$x rows<br>";
//$x=0;

if ($x==0) {
    er(3);
    }

$data=mysqli_fetch_assoc($rawdata);

echo "min = $data[min]<br>max = $data[max]<br>";
$min = $data['min'];
$max = $data['max'];
$x=  rand($min, $max);
echo "<br>rnd = $x<br>";

$q = 'select * from cap where capid<=$x';

$rawdata = mysqli_query($ddb, $q);

$x = mysqli_num_rows($rawdata);
echo "$x rows<br>";
//$x=0;

if ($x==0) {
    er(3);
    }

$data=mysqli_fetch_assoc($rawdata);