上一主题/下一主题的实现

第一种方法：定义通用函数

\nfunction shownext(){
\nglobal thisid;
\nquery=”select * from TABLE_NAME where id>thisid order by id limit 1″;
\nresult=mysql_query(query);
\nif(result=0){
\necho “已经是第一个主题了”;
\n}else{
\nif(row=mysql_fetch_array(result))
\nnextid=row["id"];
\necho “<a href=’xxx.php?id=<?=nextid?>‘>下一主题</a>”;
\n}
\n}
\n
function showpre(){
\nglobal thisid;
\nquery=”select * from TABLE_NAME where id<thisid order by id limit 1″;
\nresult=mysql_query(query);
\nif(result=0){
\necho “已经是最后一个主题了”;
\n}else{
\nif(row=mysql_fetch_array(result))
\npreid=row["id"];
\necho “<a href=’xxx.php?id=<?=preid>’>上一主题</a>”;
\n}
\n}
\n
\n

这里的 thisid 为当前主题的id


第二种方法：假设有一个主题链接为 (当前id为100)

detail.php?id=100&action=pre

或者

detail.php?id=100&action=next

然后在主题显示页面detail.php取记录时使用如下条件语句

\nswitch(acttion) {
\n    case ‘next’:
\n      sql = “select * from table where id > id limit 0,1″;
\n      break;
\n    case ‘prev’:
\n      sql = “select * from table where id < id order by id desc limit 0,1″;
\n      break;
\n    default:
\n      sql = “select * from table where id = id”;
\n  }
\n
\n

\n