Question

我的数据库中有两个名为“branch”和“course”的表。我想在选择选项中显示每个表的一列的内容。我可以成功检索一列，但是当我尝试从多个表中检索数据时，它会给我一个“结果集已关闭”的异常。

这是我的代码： -

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import="java.sql.DriverManager"%>
<%@page import="java.sql.ResultSet"%>
<%@page import="java.sql.Statement"%>
<%@page import="java.sql.Connection"%>
<html>
<head>
<title>Type of Test</title>
</head>
<body>
      <%
  Connection con=null;
  Statement s=null;
  ResultSet r=null;
  ResultSet r1=null;
 try
        {
      Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
      con=DriverManager.getConnection("jdbc:odbc:online_testing");
      s=con.createStatement();  
      r=s.executeQuery("select * from branch");    
      r1=s.executeQuery("select * from course");
        }
        catch(Exception e)
        {
        response.setContentType("text/html");
        out.println(e.toString());
        }
 %>
<form action="Decidetest" method="post"> 
    <table align="center">
    <tr>
    <td>Select Branch:-</td>
     <td>
                        <select name="branch">
          <%
                while(r.next()){
                String codeValue = r.getString("code");
    %>
               <option value="<%=codeValue%>"><%=codeValue%></option>
               <%
               }
    r.close();
        %>
            </select>
                    </td>
        </tr>

           <tr>
                    <td>Select Course:-</td><td>
                        <select name="branch">
                <%
                while(r1.next()){
                    String courseValue = r1.getString("course");
        %>
               <option value="<%=courseValue%>"><%=courseValue%></option>
                <%
               }
    r1.close();
    s.close();
    con.close();
        %>
            </select>
                    </td>
        </tr>
            <tr><td><input type="submit"></td><td><input type="reset"></td></tr>
            </table>
</form>
</div>
</body>
</html>

Answer 1

尝试将其分为2个单独的语句：

s = con.createStatement();
s1= con.createStatement();
r = s.executeQuery("select * from branch");    
r1=s1.executeQuery("select * from course");

在jsp中检索多个表的内容

1 个答案: