Java 尝试以相同的形式从选择选项中获取值
我试图从选择选项中获得价值。但它似乎无法得到,因为它的形式。我该怎么做?我的意思是从选项select中去掉值Java 尝试以相同的形式从选择选项中获取值,java,sql,database,jsp,options,Java,Sql,Database,Jsp,Options,我试图从选择选项中获得价值。但它似乎无法得到,因为它的形式。我该怎么做?我的意思是从选项select中去掉值 <strong>Select a product :</strong> <select name="stockid"> <c:forEach var="row" items="${STOCKS1.rowsByIndex}"> <option selected><c:out value="${r
<strong>Select a product :</strong>
<select name="stockid">
<c:forEach var="row" items="${STOCKS1.rowsByIndex}">
<option selected><c:out value="${row[0]}"/></option>
</c:forEach>
</select>
</p>
<%!int query = 0; %>
<%
if(request.getParameter("stockid") != null){
Connection connection = DriverManager.getConnection(
"jdbc:derby://localhost:1527/healthdb", "nbuser", "nbuser");
PreparedStatement statement = connection.prepareStatement("select stockqty from stocks where stockid = ?");
statement.setString(1,request.getParameter("stockid"));
ResultSet resultset =
statement.executeQuery( ) ;
if(resultset.next()){
out.print(resultset.getString("stockqty"));
query = resultset.getInt("stockqty");
}
else
out.print("lol");}%>
选择一种产品:
1。)如果选择了,,则无法选择选择中的所有项目!没有multiple=“multiple”
如果您可以选择多个名称
必须是此处的数组stockid[]
<select name="stockid[]">
将为查询设置一个字符串,该字符串将被引用
错
你需要
select stockqty from stocks where stockid = 1
试一试
此外,您还应该测试为空
String res = request.getParameter("stockid");
if(res != null && !res.isEmpty()){
库存数量的模式类型是什么?我认为对于任何类型,都不能任意调用getString()
或getInt()
。您必须调用与列类型相对应的适当方法。stockqty是int。当我使用getstring时,它恰好是正确的。@SabeehHasan:从OP的问题中我们可以看到它是Derby
:jdbc:derby://localhost:1527/
statement.setString(1,request.getParameter("stockid"));
select stockqty from stocks where stockid = "1"
select stockqty from stocks where stockid = 1
statement.setInt(1,Integer.parseInt(request.getParameter("stockid"));
String res = request.getParameter("stockid");
if(res != null && !res.isEmpty()){