Scalable Alternative

Another possibility is that we can just get all the questions and set the internal pointer to a random row. While it does require a large space for storing the result, this solution will work better if our QuIDs have a lot of holes, if questions are often deleted, or if they are entered in nonsequential order. The code necessary follows the logic in Figure 13.3 and looks like this:

PHP

//The only portion of this code that changed was the constructor

function Question( ) {
  MySQL_connect('sql.useractive.com', 'bigfun', '[REDACTED]');
  MySQL_select_db('bigfun');
  $res = MySQL_query ("select QuID from Questions" );
  $WhichRow = rand(0,MySQL_num_rows($res)-1);
  $WhichQuid = MySQL_result($res,$WhichRow,0);
  $res = MySQL_query ("select * from Questions where QuID = $WhichQuid" );
  $sqlquestion = MySQL_fetch_array ($res );
  $sqlQuid = $sqlquestion["QuID"];
  $this->Q = $sqlquestion["Q"];
  $this->idkey= $sqlquestion["QuID"];
  MySQL_free_result($res);
  $res = MySQL_query ("select * from Answers where WhichQuestion =
         $sqlQUid");
  $numrows = MySQL_num_rows($res);
  for($i=0;$i<$numrows;$i++) {
   $temp = MySQL_fetch_array($res);
   array_push ($this->A , $temp["AnswerChoice"]);
  }
return $this;
//     }

No loop, cleaner flowchart.

Only a little bit of the code was changed, the part that selected the QuID used.

PHP

$res = MySQL_query ("select QuID from Questions" );

Get all the QuIDs of all the questions. Load them all into RAM.

PHP

$WhichRow = rand(0,MySQL_num_rows($res)-1);

Choose a random row of data. The rows are contiguous and zero-based. There are MySQL_num_rows($res) of them. The bounds on rand are inclusive.

PHP

$WhichQuid = MySQL_result($res,$WhichRow,0);

This code selects a field; specifically, it selects the QuID in the randomly selected row.

PHP

$res = MySQL_query ("select * from Questions where QuID = $WhichQuid" );

This code retrieves the information about the Question whose QuID we have chosen. The rest of the code is the same between the two versions.