PHP 在 for() 循环中从 mysql 获取结果

Question

我有一个'地图'之类的东西我正在做的事情。我画出每个图块，然后检查数据库以查看是否有人位于该图块处。

代码有效，但仅适用于数据库中的第一个结果。

谁能帮忙。非常感谢。

$sqlw = "SELECT id, player_coord_x, player_coord_y FROM player_game WHERE     world_id='$world'";
$world_result = $player_stat->query($sqlw);


?>

<div class='map-grid'>

    <?
    $id = '';
    $size = 16;
    for($i = 1; $i <= $size; $i++) {
        echo "<div class='map-grid-row'>";
        for ($j=1; $j <= $size; $j++) {

            // check for player at location
            if ($world_result->num_rows > 0) {
                while($w_row = $world_result->fetch_assoc()) {

                    $player_coord_x = $w_row['player_coord_x'];
                    $player_coord_y = $w_row['player_coord_y'];
                    $id = $w_row['id'];

                }
            }

            if ($player_coord_x == $i and $player_coord_y == $j){

                echo "<div class='map-grid-cell high'>";
                echo "XXX";
                echo "</div>";
            }else{

                echo "<div class='map-grid-cell high'>";
                echo "<span class=\"map-small\">(x-$i y-$j)</span>";
                echo "</div>";
            }

        }
        echo "</div>";
    }
    ?>  

</div>

Answer 1

$sqlw = "SELECT id, player_coord_x, player_coord_y FROM player_game WHERE world_id='$world'";
$world_result = $player_stat->query($sqlw);

if($world_result->num_rows > 0){
  while($w_row = $world_result->fetch_assoc()){
    //first type of array
    $player[] = array(
      'x'        => $w_row['player_coord_x'], //your player X record
      'y'        => $w_row['player_coord_y'], //your player Y record
      'id'       => $w_row['id'] //your player id
    );

    //second type of array
    // OR store player's X and Y as key of array
    $player[$w_row['player_coord_x'] . '-' . $w_row['player_coord_y']] = $w_row['id'];
    // This are only if the player record will never repeat
  }
}

?>

<div class="map-grid">
  <?php 
    $size = 16; 
    for($i = 1; $i <= $size; $i++){ 
      echo '<div class="map-grid-row">';
      for($j = 1; $j <= $size; $j++){
        //with first type of array
        $exists = false;
        foreach($player as $play){
          if($play['x'] == $i && $play['y'] == $j){
            $exists = true;
            break; // break the loop once you got the result.
          }
        }
        if($exists){ //Player exists? if no detect in foreach loop above, default exists would return false.
          echo '<div class="map-grid-cell high">';
          echo 'XXX';
          echo '</div>';
        } else {
          echo '<div class="map-grid-cell high">';
          echo '<span class="map-small">(x-' . $i . ' y-' . $j . ')</span>';
          echo '</div>';
        }



        //second type of array
        //Check if the key exists and if it's empty.
        if(isset($player[$i.'-'.$j]) && !empty($player[$i.'-'.$j])){
          echo '<div class="map-grid-cell high">';
          echo 'XXX';
          echo '</div>';
        } else {
          echo '<div class="map-grid-cell high">';
          echo '<span class="map-small">(x-' . $i . ' y-' . $j . ')</span>';
          echo '</div>';
        }
      }
    }
  ?>
</div>