ページングをmysqlとpostgreSQLでソース比較

mysql

//ページング設定
$page = $_REQUEST['page'];
if($page == ''){
$page = 1;
}

$page = max($page, 1);

//最終ページを取得する
pg_query($conn, "SELECT COUNT(*) AS cnt FROM posts");
$recordSet = pg($sql);
$table = pg_fetch_assoc($recordSet);
$maxPage = ceil($table['cnt'] / 5);
$page = min($page,$maxPage);
$start = ($page - 1) * 5;

//SQLの結果から得た行数を取得
$num = pg_num_rows($result);

if($num > 0){
for( $i=0; $i<$num; $i++ ){
$rows = pg_fetch_array($result, NULL, PGSQL_ASSOC);
print('<div class="comments"><p class="comments_message">'.$rows['message']);
print('</p><p class="comments_time">'.$rows['time'].'</p>');
print ('<p><a href="delete.php?id=' .$rows['id']. '">[削除]</a>');
print ('<a href="edit.php?id=' .$rows['id']. '">[編集]</a></p></div><!-- . comments-->');

}
}

PostgreSQL

$max_num = 15;
$limit = $max_num * 2;
$offset = $_GET["of"];
if(empty($offset) || !ctype_digit($offset)){
$offset = 0;
$pref_offset = null;
}else{
$pref_offset = $offset - $max_num;
}
if($pref_offset <= 0){
$pref_offset = 0;
}

//$conn = pg_connect("...");

$sql = "SELECT * FROM posts ORDER BY id asc LIMIT $limit OFFSET $offset";
$result = pg_query($conn,$sql);
$num = pg_num_rows($result);
if($num > 0){
if($num <= $max_num){
$seek = $num;
$next_offset = null;
}else{
$seek = $max_num;
$next_count = $num - $max_num;
$next_offset = $offset + $max_num;
}
$st = $offset + 1;
$ed = $offset + $seek;

echo "{$st}件から{$ed}件を表示中<br />";
for($i=0;$i<$seek;$i++){
$data = pg_fetch_assoc($result,$i);
//表示する
echo "<div>".$data["message"]."</div>\n";
}
}
if(!empty($pref_offset)){
echo "<a href=\"index.php?of={$pref_offse}\">前の{$max_num}件</a>\n";
}
if(!empty($next_offset)){
echo "<a href=\"index.php?of={$next_offset}\">次の{$next_count}件</a>\n";
}