随机重复相似的字符串，即使在改变种子之后

如何让这个随机字符串生成器创建随机字符串。总是得到重复。数组通常由0 - 10个元素组成，但在重复时仍然得到相同数量的床和浴室，我知道统计上它是混乱的。

如何消除重复?

    for ($i = 0; $i <= 1000000; $i++) {
      srand($i);
      $price = rand(20000, 1000000);
      $bed = rand(0, 20);
      $bath = rand(0, 7);
      $addressnum = rand(100, 10000);
      $address = (int) preg_replace('/'D/', '', $addressnum) . " lol st";
      $province = $f_contents[rand(0, count($f_contents) - 1)];
      $postedby = 3;
      $description = $de_contents[rand(0,count($de_contents) - 1)];
      $status = "Unsold";
      $type = $status_a[array_rand($status_a)];
      $category = $category_type[array_rand($category_type)];
      $size = rand(100,100000);
      $builtin = rand(1850, 2013);
      $queryString = "INSERT INTO listings 
      (PRICE, ADDRESS, PROVINCE, DESCRIPTION, STATUS, TYPE, CATEGORY, SIZE, BUILTIN, BED, BATH, POSTED_BY) VALUES 
      ($price, '$address', '$province', '$description', '$status', '$type', '$category', $size, $builtin, $bed, $bath, $postedby)";
      echo $queryString . "<br>"; 
      $query = $db -> query($queryString);
    }