Question

我有一个名为tbl_Teacher的表，其数据为：

Teacher_ID   Lastname   Firstname   Department
1               aaa         Joe         Math
2               bbb         Jenny       History
3               ccc         Mark        Math

我创建了一个ASP SELECT。如果我选择＆＃34; aaa，Mark＆＃34;从下拉列表中，然后＆＃34;匹配＆＃34;将在第二个下拉列表中自动选择。但是，选择Last和Firstname后，它没有任何值;它显示没有找到任何部门。

我做错了什么？有人可以帮忙吗？

非常感谢。

以下是代码：

<%  Set rsSelect = Server.CreateObject("adodb.recordset")
    strSQL = "SELECT Lastname, Firstname, Teacher_ID FROM tbl_Teacher;"
    rsSelect.Open strSQL, strCon
    Dim strID
    strID = Request.QueryString("Teacher_ID")
    if not rsSelect.eof then %>
        <select name="Name" onChange="this.form.action='Teacher.asp';this.form.submit();">
             <option value="1">Select a Teacher</option>
             <% do until rsSelect.eof %>
                <option value="<%= rsSelect(0) %>" <% if trim(request.Form("Name")) = trim(rsSelect(0)) then response.write " selected "end if %>><%= rsSelect("Lastname") %>, <%= rsSelect("Firstname") %></option>
                <%  rsSelect.MoveNext
             loop       %>
         </select>
         <% end if 

    if trim(request.Form("Name")) <> "" then
        strSQL = "SELECT Department FROM tbl_Teacher WHERE Teacher_ID = '" & Request.Form("strID") & "';"
        Set rsSelect = Server.CreateObject("adodb.RecordSet")
        rsSelect.Open strSQL, strCon
        if not rsSelect.eof then %>
            <select name="Department">
                <% do until rsSelect.eof       %>
                    <option value="<%= rsSelect("Department") %>"><%= rsSelect("Department") %></option>
                    <% rsSelect.MoveNext
                loop %>
            </select>
            <% else %>
                <i>No Department found</i>
            <%  end if
        else
            response.write "<i>Select a Department</i>"
        end if %>

Answer 1

使用teacher_id比使用名称或代码要好得多：

<%Set rsSelect = Server.CreateObject("adodb.recordset")
strSQL = "SELECT Teacher_ID, Lastname, Firstname FROM tbl_Teacher;"
rsSelect.Open strSQL, strCon, 1, 1
Dim strID
strID = Request.QueryString("Teacher_ID")
if not rsSelect.eof then %>
    <select name="Name" onChange="this.form.action='Teacher.asp';this.form.submit();">
         <option value="1">Select a Teacher</option>
         <% do until rsSelect.eof %>
            <option value="<%= rsSelect(0) %>" <% if request.Form("teacherId") = rsSelect(0) then response.write " selected "end if %>><%= rsSelect("Lastname") %>, <%= rsSelect("Firstname") %></option>
            <%  rsSelect.MoveNext
         loop       %>
     </select>
     <% end if

但是，根据您从数据库中恢复的内容，您在下面的代码中遇到了另一个问题。我建议您重新考虑您的设计，因为您在这里会让自己感到困惑，并在以后将错误的代码打开。尝试将Departments分成自己的表中的简洁值列表;这将防止任何人在以后进入不受欢迎或拼写错误的部门。然后，您需要以下内容来替换您拥有的内容......

if request.Form("teacherId")) <> "" then
    Set rsSelect = Server.CreateObject("adodb.RecordSet")
    strSQL = _
        "SELECT " & _ 
            "tbl_department.departmentId, " & _ 
            "tbl_department.departmentName, " & _ 
            "tbl_teacher.department " & _ 
        "FROM " & _ 
            "tbl_departments " & _ 
            "LEFT JOIN " & _ 
            "tbl_teacher " & _ 
                "ON  tbl_departments.departmentId = tbl_teacher.department AND " & _ 
                    "tbl_teacher.teacherId = " & request.Form("teacherId")
    rsSelect.Open strSQL, strCon
    if not rsSelect.eof then %>
        <select name="Department">
            <% do until rsSelect.eof       %>
                <option <%if rsSelect("department")&""<>"" then response.write(" selected ")%> value="<%= rsSelect("Department") %>"><%= rsSelect("Department") %></option>
                <% rsSelect.MoveNext
            loop %>
        </select>
        <% else %>
            <em>No Department found</em>
        <% end if
    else %>
        <em>Select a Department</em>
    <% end if %>

但是...... 这里的SQL安全性存在很大问题 - 上面的代码让您对SQL injection attacks敞开大门，应该仔细考虑。

从下拉填充第二类中选择

1 个答案: