我正在尝试编写一个 jdo 查询，其中我必须根据用户在 jsp 上选择的类别获取一组值...我的查询看起来像这样
Query query2 = pm.newQuery("select from " + ProductDB.class.getName()+ "where pCategory = " document.getElementById("cname").text);
现在在我的 jsp 页面上，我有一个动态下拉框，并且在标签中我将 id 标签指定为“cname”。因此，当我执行上述查询时，我希望它能获得用户选择的类别。
但是我收到此错误：
Syntax error on token "document", delete this token
我的选择标签如下所示：
<select name = "cname" id="cname">
.
.
.
</select>
我在这里想念什么？
更新：
我将我的整个jsp文件代码放在下面：
<%@ page contentType="text/html;charset=UTF-8" language="java"%>
<%@ page import="java.util.*"%>
<%@ page import="javax.jdo.Query"%>
<%@ page import="javax.jdo.PersistenceManager"%>
<%@ page import="com.google.appengine.api.users.User"%>
<%@ page import="com.google.appengine.api.datastore.Key"%>
<%@ page import="com.google.appengine.api.users.UserService"%>
<%@ page import="com.google.appengine.api.users.UserServiceFactory"%>
<%@ page import="java.net.*"%>
<%@ page import="javax.servlet.http.HttpServletRequest"%>
<%@ page import="com.nerdy.needs.*"%>
<html>
<head>
<title>Product Inventory</title>
<META HTTP-EQUIV="Refresh" CONTENT="450">
<link rel="stylesheet" href="login.css" type="text/css" />
</head>
<h1 align="center">Product Inventory</h1>
<body>
<form>
<table>
<tr>
<td>View</td>
<td><select name="cname" id="cname">
<option value="all">All</option>
<%
PersistenceManager pm = PMF.get().getPersistenceManager();
Query query = pm.newQuery("select cname from "
+ CategoryDB.class.getName());
List<String> categories = new ArrayList<String>();
categories = (List<String>) query.execute();
String[] c = categories.toArray(new String[categories.size()]);
for (int i = 0; i < c.length; i++) {
String s = c[i];
%>
<option value="<%=s%>"><%=s%></option>
<%
}
%>
</select></td>
<td>Products</td>
</tr>
</table>
</form>
<%
if (document.getElementById("cname").value == "all") {
PersistenceManager pm1 = PMF.get().getPersistenceManager();
Query query1 = pm1.newQuery("select * from "
+ ProductDB.class.getName());
List<ProductDB> prods1 = (List<ProductDB>) query1.execute();
if (prods1.isEmpty()) {
%>
<table class="items">
<tr>
<th class="main">Image</th>
<th class="main">Category</th>
<th class="main">Name</th>
<th class="main">Price</th>
<th class="main">Description</th>
</tr>
<tr class="lightBlue">
<td class="actions" colspan=100%>
<p>No items were found.</p>
</td>
</tr>
</table>
<%
} else {
%>
<table class="topics">
<tr>
<th class="main">Image</th>
<th class="main">Category</th>
<th class="main">Name</th>
<th class="main">Price</th>
<th class="main">Description</th>
</tr>
<%
for (ProductDB p : prods1) {
%>
<tr>
<td>
<p><b> <img width="100" height="100"
src="http://localhost:8888/serve?id= <%=p.getProductImage()%>">
</b></p>
</td>
<td>
<p><b><%=p.getProductCategory()%></b></p>
</td>
<td>
<p><b><%=p.getProductName()%></b></p>
</td>
<td>
<p><b><%=p.getProductPrice()%></b></p>
</td>
<td>
<p><b><%=p.getProductDescription()%></b></p>
</td>
</tr>
<%
}
%>
</table>
<%
pm1.close();
}
} else {
PersistenceManager pm2 = PMF.get().getPersistenceManager();
Query query2 = pm.newQuery("select * from "
+ ProductDB.class.getName() + "where pCategory = "
+ document.getElementById("cname").value);
List<ProductDB> prods2 = (List<ProductDB>) query2.execute();
if (prods2.isEmpty()) {
%>
<table class="items">
<tr>
<th class="main">Image</th>
<th class="main">Category</th>
<th class="main">Name</th>
<th class="main">Price</th>
<th class="main">Description</th>
</tr>
<tr class="lightBlue">
<td class="actions" colspan=100%>
<p>No items were found.</p>
</td>
</tr>
</table>
<%
} else {
%>
<table class="topics">
<tr>
<th class="main">Image</th>
<th class="main">Category</th>
<th class="main">Name</th>
<th class="main">Price</th>
<th class="main">Description</th>
</tr>
<%
for (ProductDB p : prods2) {
%>
<tr>
<td>
<p><b> <img width="100" height="100"
src="http://localhost:8888/serve?id= %=p.getProductImage()%>">
</b></p>
</td>
<td>
<p><b><%=p.getProductCategory()%></b></p>
</td>
<td>
<p><b><%=p.getProductName()%></b></p>
</td>
<td>
<p><b><%=p.getProductPrice()%></b></p>
</td>
<td>
<p><b><%=p.getProductDescription()%></b></p>
</td>
</tr>
<%
}
%>
</table>
<%
pm2.close();
}
}
%>
</body>
</html>
我在两个地方收到“文档无法解析”错误 - 一个在 if 语句中
if(document.getElementById("cname").value=="all")
另一个在查询语句
Query query2 = pm.newQuery("select * from " + ProductDB.class.getName()+ "where pCategory = " + document.getElementById("cname").value);
谁能帮我找出问题所在？