该例子演示了无限级分类的显示和添加.只用一个数据表实现记录无限级分类,关键是每条记录都记录了上一层类别的ID(parentid),然后通过一个递归函数来不断将类别显示出来.
ASP递归无限级分类函数 复制代码 代码如下: <% '函数:getCatagory '功能:获得分类列表 '参数:cat_arr -> 分类数组(Rscordset:id:分类编号,pid:上级分类,classname:分类名称,childs:子分类) ' 按此输出些sql语句,用getRows获取得到的数据 ' cat_pid -> 上级分类编号 ' cat_childs -> 下级分类编号 ' cat_select -> 选择的分类 ' cat_dir -> 分类级别 '返回:返回分类列表(Option)
dim conn,cmd,rs,cat_arr Set conn = Server.CreateObject("ADODB.Connection") Set cmd = Server.CreateObject("ADODB.Command")
conn.Open "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" & Server.MapPath("db1.mdb") cmd.ActiveConnection = conn cmd.CommandText = "Select * from cate order by id desc" Set rs = cmd.Execute cat_arr = rs.GetRows() Set rs = Nothing Set cmd = Nothing Set conn = Nothing
getCatagory cat_arr,0,"","","","{$cat.dir}├─<a href=""?id={$cat.id}"" title=""分类级别:{$cat.dir} 分类编号:{$cat.id} 分类上级编号:{$cat.pid} 分类名称:{$cat.name} 分类子分类:{$cat.childs}"">{$cat.name} </a><br />"&vbcrlf
function getCatagory(byval cat_arr,byval cat_pid,byval cat_childs,byval cat_select,byval cat_dir,byval format) dim i,tmp if isArray(cat_arr) then for i=0 to ubound(cat_arr,2) if cat_arr(1,i) = cat_pid and instr("," & cat_childs & ",","," & cat_arr(0,i) & ",") = 0 then tmp = format if instr(tmp,"{$cat.dir}")>0 then tmp = replace(tmp,"{$cat.dir}",cat_dir) if instr(tmp,"{$cat.id}")>0 then tmp = replace(tmp,"{$cat.id}",cat_arr(0,i)) if instr(tmp,"{$cat.pid}")>0 then tmp = replace(tmp,"{$cat.pid}",cat_arr(1,i)) if instr(tmp,"{$cat.name}")>0 then tmp = replace(tmp,"{$cat.name}",cat_arr(2,i)) if instr(tmp,"{$cat.childs}")>0 then tmp = replace(tmp,"{$cat.childs}",cat_arr(3,i)) response.write tmp call getCatagory(cat_arr,cat_arr(0,i),cat_childs,cat_select,cat_dir & "│",format) end if next end if end function %> 转载的一个递归函数,比较典型的应用,没有特别算法,目前我们一般常见的无限级分类函数均大同小异。简单整理了一下,包括示例打包getCatagory.rar
*大类1 └二级小类1 └三级小类1 └四级小类1 └五级小类1 *大类2 └二级小类2 *大类3
数据库说明:数据库db.mdb,classTable表的结构:classid类别ID(自动增长) parentid 父级ID 默认为0 (0代表最高级) classname类别名,classdepth是为了记录类别的级数 ———————————————- | classid| classname| parentid | classdepth | ———————————————-
主要代码:
复制代码 代码如下: //先取出最高级(parentid=0)的分类
<% set conn=server.createobject("adodb.connection") conn.open "Provider=Microsoft.Jet.Oledb.4.0;data source="&server.MapPath("db.mdb") set rs1=server.createobject("adodb.recordset") sql1="select * from Classtable where parentid=0 order by classid" rs1.open sql1,conn,1,1 if rs1.eof or rs1.bof then response.write"还没分类!" else while not rs1.eof id1=rs1("classid") name1=rs1("classname")
response.write "*<a href='class.asp?id="&id1&"&name="&name1&"‘>"&name1&"</a><br>" parentid1=rs1("parentid") call reclass(id1) rs1.movenext wend end if rs1.close set rs1=nothing
sub reclass(id) ‘递归调用函数,生成一个类别代码 set rs=server.createobject("adodb.recordset") sql="select * from classtable where parentid="&id rs.open sql,conn,1,1 i=1 while not rs.eof id0=rs("classid") classname0=rs("classname") parentid0=rs("parentid") classdepth0=rs("classdepth") brstr="" for j=1 to classdepth0 brstr=" "&brstr next response.write(brstr&"└<a href='class.asp?id="&id0&"&name="&classname0&"‘>"&classname0&"</a><br>") call reclass(id0)
rs.movenext i=i+1 wend rs.close set rs=nothing end sub
if request("a")="add" then call add end if if request("name")<>"" then %> <table width="80%" align="center" cellpadding="0″ cellspacing="0″> <form action="class.asp?a=add&id=<%=request("id")%>" method="post"> <tr> <td> </td> <td>在<font color="#FF0000″><%=request("name")%></font>添加小类</td> </tr> <tr> <td>类别名:</td> <td><input name="classname" type="text" id="classname"></td> </tr> <tr> <td> </td> <td><input type="submit" name="Submit" value="提交"></td> </tr> </form> </table> <%end if sub add '添加类别 id=request("id") classname=request("classname") set rs=server.createobject("adodb.recordset") rs.open "select parentid,classdepth from classtable where classid="&id,conn,1,1 parentid=rs(0) classdepth=rs(1)+1 rs.close set rs=nothing sql="INSERT INTO classtable (classname,parentid,classdepth) values ('"&classname&"‘,"&id&","&classdepth&")" conn.execute sql response.Write"<script>alert('添加成功!');location.href='class.asp';</script>" end sub %>
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