java - 准备好的语句的setString不起作用

Question

我正在尝试对准备好的语句使用 setString(index, parameter) 方法来创建 ResultSet 但它似乎没有正确插入。我知道查询是正确的，因为我在后面的 else 中使用了相同的查询(减去对 setString 的需要)。这是我目前拥有的代码:

**据我了解，ps.setString(1, "'%"+ committeeCode + "%'"); 应该替换 ?在查询中，但我的输出另有说明。感谢您的帮助。

public String getUpcomingEvents(String committeeCode) throws SQLException{
        Context ctx = null;
        DataSource ds = null;
        Connection conn = null;
        PreparedStatement ps  = null;
        ResultSet rs = null;

    StringBuilder htmlBuilder = new StringBuilder();
    String html = "";

    try {
        ctx = new InitialContext();
        ds = (DataSource) ctx.lookup("java:ConnectDaily");
        conn = ds.getConnection();

        if(committeeCode != null){
            //get all events
            String queryStatement = "SELECT " + 
                    .......
                    "WHERE c.calendar_id = ci.calendar_id AND c.short_name LIKE ? " + 
                    "AND ci.style_id = 0 " + 
                    "AND ci.starting_date > to_char(sysdate-1, 'J') " + 
                    "AND ci.item_type_id = cit.item_type_id " + 
                    "ORDER BY to_date(to_char(ci.starting_date), 'J')";




            ps = conn.prepareStatement(queryStatement);

            ps.setString(1, "'%" + committeeCode + "%'");
            System.out.println(queryStatement);

            rs = ps.executeQuery();

            if (rs != null){
                while(rs.next()){
                    String com = rs.getString("name");
                    String comID = rs.getString("short_name");

                    String startTime = rs.getString("starting_time");
                    String endTime = rs.getString("ending_time");
                    String name = rs.getString("contact_name");
                    String desc = rs.getString("description");
                    String info = rs.getString("contact_info");
                    String date = rs.getString("directory");

                    htmlBuilder.append("<li><a href='?com="+committeeCode+"&directory=2014-09-10'>"+com+" - "+ date +" - "+startTime+" - "+endTime+"</a> <!-- Link/title/date/start-end time --><br>");
                    htmlBuilder.append("<strong>Location: </strong>"+comID+"<br>");
                    htmlBuilder.append("<strong>Dial-In:</strong>"+com+"<br>");
                    htmlBuilder.append("<strong>Part. Code:</strong>"+info+"<br>");
                    htmlBuilder.append("<a href='http://nyiso.webex.com'>Take me to WebEx</a>");
                    htmlBuilder.append("</li>");            
                    }
            }
            html = htmlBuilder.toString();

. . .

    }catch (NamingException e) {
        e.printStackTrace();
        //log error and send error email
    } catch (SQLException e) {
        e.printStackTrace();
        //log error and send error email
    }finally{
        //close all resources here
        ps.close();
        rs.close();
        conn.close();
    }
    return html;

}

输出

14:18:22,979 INFO  [STDOUT] SELECT  to_char(to_date(to_char(ci.starting_date), 'J'),'mm/dd/yyyy') as start_date,  to_char(to_date(to_char(ci.ending_date), 'J'),'mm/dd/yyyy') as end_date,  to_char(to_date(to_char(ci.starting_date), 'J'),'yyyy-mm-dd') as directory,  ci.starting_time,  ci.ending_time,  ci.description,  cit.description as location,  c.name,  c.short_name,  ci.add_info_url,  ci.contact_name,  ci.contact_info FROM calitem ci, calendar c, calitemtypes cit WHERE c.calendar_id = ci.calendar_id AND c.short_name LIKE ? AND ci.style_id = 0 AND ci.starting_date > to_char(sysdate-1, 'J') AND ci.item_type_id = cit.item_type_id ORDER BY to_date(to_char(ci.starting_date), 'J')

Answer 1

setString 中不需要引号:

ps.setString(1, "%" + committeeCode + "%");

此方法会将指定的 String 绑定(bind)到第一个参数。它不会改变保存在queryStatement中的原始查询String。