java - 如何在jsp中显示SQL的结果？

Question

下面是jsp中的SQL语句。正如你所看到的，我想显示我的 SQL 结果，但没有这样做。我相信我的方法是错误的。请帮助我。

Connection connection = null;
        try{
        Class.forName("oracle.jdbc.driver.OracleDriver");
        connection = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe", "system", "oracle");
        Statement statement = connection.createStatement();
        String query ="SELECT COUNT(CATEGORY) AS COUNTER FROM CLASSIFY WHERE CATEGORY='REMEMBER'";
        ResultSet rst =statement.executeQuery(query);

        String counteRemember= rst.getString("COUNT");
        out.println(counteRemember);
        }
        catch(ClassNotFoundException e)
        {
            out.print("error1");
        } 
        catch (SQLException e) 
        {
            out.print("error2");
        }   

Answer 1

您调用了错误的列(COUNT 是您正在调用的 sql 函数，但不是结果列):

String counteRemember= rst.getString("COUNT");

将其更改为:

if(rst.next()) {
  String counteRemember= rst.getString("COUNTER");

}

或者:

String counteRemember= rst.getString(1);