PHP get results from mysql in a for() loop - php

Question

I have a 'map' kind of thing for something im working on. Im drawing each tile out and then checking against a database to see if somebody is located at that tile.
The code works but only for the first result in the db.
Can anyone help. many thanks.
$sqlw = "SELECT id, player_coord_x, player_coord_y FROM player_game WHERE world_id='$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>