Drupal 7 实现上一篇下一篇的简单方法

/**
* myNodePrevNext
* 文章上一篇下一篇
* $nid - 节点id
* $type - 节点类型
*/
function myNodePrevNext($nid, $type)
{
$output = '

• ';

$sql_previous = "SELECT n.nid, n.title, url.alias "
. "FROM {node} AS n "
. "LEFT JOIN {url_alias} AS url "
. "ON concat('node/',n.nid)=url.source "
. "WHERE n.nid . "ORDER BY n.nid DESC "
. "LIMIT 0, 1";

$result_previous = db_query($sql_previous, array(':nid' => $nid, ':type' => $type));

$strings = array();

foreach ($result_previous as $data)
{
$data->url = ($data->alias) ? $data->alias : '/node/' . $data->nid;

$output .= '

$sql_next = "SELECT n.nid, n.title, url.alias "
. "FROM {node} AS n "
. "LEFT JOIN {url_alias} AS url "
. "ON concat('node/',n.nid)=url.source "
. "WHERE n.nid > :nid AND n.type = :type "
. "ORDER BY n.nid ASC "
. "LIMIT 0, 1";
$result_next = db_query($sql_next, array(':nid' => $nid, ':type' => $type));

$strings = array();

foreach ($result_next as $data)
{
$data->url = ($data->alias) ? $data->alias : '/node/' . $data->nid;

$output .= '

$output .= '

return $output;
}