rs.getInt()的问题

esther_wgh 2005-09-28 06:35:26

rs=smt.executeQuery(sql);
rs.next();
today=rs.getInt(2);
select=(int)Math.floor(hour/4)+1;
sql="select * from total";
rs=smt.executeQuery(sql);
rs.next();
total=rs.getInt(1);
这是程序中的一小段，测试没有问题，为什么在运行程序后页面上出现无效的游标状态的提示。
如果把total=rs.getInt(1)去掉就没有这个提示。？？？

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切换为时间正序

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trumplet 2005-09-28

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你贴出的代码太少，至少贴到出错的那行吧。

woolceo 2005-09-28

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如果你是用了Statement的话是不能自由移动游标的，建议用PreparedStatement。

woolceo 2005-09-28

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你的PreparedStatement设置了什么类型的操作？
PreparedStatement pstmt = conn.prepareCall("select xxxxxx from xxxxx",ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
这样就允许游标移动了。

esther_wgh 2005-09-28

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请各位高手帮忙。

package cn.com.dao.chivementdao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import cn.com.util.DBConnection; import cn.com.util.DBSql; import cn.com.vo.chivementvo.ChivementVo; public class ExamDao { private Connection conn = DBConnection.getConnectionOracle(); private ChivementVo examVo; public ExamDao() { } public ExamDao(ChivementVo examVo) { super(); this.examVo = examVo; } /** * 全部查询 */ public Object[][] selectAll() { Object date[][] = null; int max = 0; int i = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(DBSql.SELECT_ALL); rs = ps.executeQuery(); // 得到列数 max = rs.getMetaData().getColumnCount(); date = new Object[getnumberAll(DBSql.SELECT_ALL_COUNT)][max]; while (rs.next()) { for (int j = 0; j < max; j++) { date[i][j] = rs.getObject(j + 1); } i++; } // rs.close(); // ps.close(); // conn.close(); } catch (SQLException e) { e.printStackTrace(); } return date; } /** * 根据学号查询 */ public Object[][] selectBySid() { Object date[][] = null; int max = 0; int i = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(DBSql.SELECT_BY_S_ID); ps.setInt(1, examVo.getS_id()); rs = ps.executeQuery(); // 得到列数 max = rs.getMetaData().getColumnCount(); date = new Object[getnumber(DBSql.SELECT_BY_S_ID_COUNT, examVo .getS_id())][max]; while (rs.next()) { for (int j = 0; j < max; j++) { date[i][j] = rs.getObject(j + 1); } i++; } // rs.close(); // ps.close(); // conn.close(); } catch (SQLException e) { e.printStackTrace(); } return date; } /** * 根据组号查询 */ public Object[][] selectByGid() { Object date[][] = null; int max = 0; int i = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(DBSql.SELECT_BY_G_ID); ps.setInt(1, examVo.getG_id()); rs = ps.executeQuery(); // 得到列数 max = rs.getMetaData().getColumnCount(); date = new Object[getnumber(DBSql.SELECT_BY_G_ID_COUNT, examVo .getG_id())][max]; while (rs.next()) { for (int j = 0; j < max; j++) { date[i][j] = rs.getObject(j + 1); } i++; } // rs.close(); // ps.close(); // conn.close(); } catch (SQLException e) { e.printStackTrace(); } return date; } /** * 根据课程号查询 */ public Object[][] selectByCid() { Object date[][] = null; int max = 0; int i = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(DBSql.SELECT_BY_C_ID); ps.setInt(1, examVo.getC_id()); rs = ps.executeQuery(); // 得到列数 max = rs.getMetaData().getColumnCount(); date = new Object[getnumber(DBSql.SELECT_BY_C_ID_COUNT, examVo .getC_id())][max]; while (rs.next()) { for (int j = 0; j < max; j++) { // System.out.println( examVo.getG_id()); date[i][j] = rs.getObject(j+1); } i++; } // rs.close(); // ps.close(); // conn.close(); } catch (SQLException e) { e.printStackTrace(); } return date; } /** * 根据姓名模糊查询 * * @return */ public Object[][] selectByName() { Object date[][] = null; int max = 0; int i = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(DBSql.SELECT_BY_S_NAME); ps.setString(1, examVo.getS_name()); ps.setString(2, "%" + examVo.getS_name() + "%"); ps.setString(3, "%" + examVo.getS_name()); ps.setString(4, examVo.getS_name() + "%"); rs = ps.executeQuery(); // 得到列数 max = rs.getMetaData().getColumnCount(); date = new Object[getnumberByName(DBSql.SELECT_BY_S_NAME_COUNT, examVo.getS_name())][max]; while (rs.next()) { for (int j = 0; j < max; j++) { date[i][j] = rs.getObject(j + 1); } i++; } } catch (SQLException e) { e.printStackTrace(); } return date; } /** * 根据课程名称模糊查询 * * @return */ public Object[][] selectByClassName() { Object date[][] = null; int max = 0; int i = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(DBSql.SELECT_BY_CLASS_NAME); ps.setString(1, examVo.getClass_name()); ps.setString(2, "%" + examVo.getClass_name() + "%"); ps.setString(3, "%" + examVo.getClass_name()); ps.setString(4, examVo.getClass_name() + "%"); rs = ps.executeQuery(); // 得到列数 max = rs.getMetaData().getColumnCount(); date = new Object[getnumberByName(DBSql.SELECT_BY_CLASS_COUNT, examVo.getClass_name())][max]; while (rs.next()) { for (int j = 0; j < max; j++) { date[i][j] = rs.getObject(j + 1); } i++; } } catch (SQLException e) { e.printStackTrace(); } return date; } /** * 修改选中学生的成绩 * */ public void updatSelectClass() { PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(DBSql.UPDATE_EXAM_BY_STUID); ps.setInt(1, examVo.getClassExamChivement()); ps.setInt(2, examVo.getS_id()); ps.setInt(3, examVo.getC_id()); ps.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); } } /** * 得到所有课程号和课程名 * * @return */ public String[] getClassNoName() { String[] classNoName = null; PreparedStatement ps = null; ResultSet rs = null; int j = 0; try { int i = getnumberAll(DBSql.SELECT_CLASS_NAME_COUNT); classNoName = new String[i + i]; ps = conn.prepareStatement(DBSql.SELECT_CLASS_NAME); rs = ps.executeQuery(); while (rs.next()) { classNoName[j] = rs.getString(1); classNoName[j + i] = rs.getString(2); j++; } } catch (SQLException e) { e.printStackTrace(); } return classNoName; } /** * 根据科目修改成绩查询学号姓名成绩 * */ public void SelectClassStuName() { int i = 0; PreparedStatement ps = null; ResultSet rs = null; int j = getnumberBySelectClassName( DBSql.SELECT_CLASS_STU_SNO_SNAME_EXAM_COUNT, examVo.getC_id()); int[] sNum = new int[j]; String[] sName = new String[j]; int[] classExam = new int[j]; try { ps = conn.prepareStatement(DBSql.SELECT_CLASS_STU_SNO_SNAME_EXAM); ps.setInt(1, examVo.getC_id()); rs = ps.executeQuery(); while (rs.next()) { sNum[i] = rs.getInt(1); sName[i] = rs.getString(2); classExam[i] = rs.getInt(3); i++; } } catch (SQLException e) { e.printStackTrace(); } examVo.setSid(sNum); examVo.setSname(sName); examVo.setClassExam(classExam); } /** * 根据科目修改成绩查询学号姓名成绩后修改成绩 * */ public void UpdateClassStuName() { // int i = 0; PreparedStatement ps = null; ResultSet rs = null; int j = getnumberBySelectClassName( DBSql.SELECT_CLASS_STU_SNO_SNAME_EXAM_COUNT, examVo.getC_id()); try { ps = conn.prepareStatement(DBSql.UPDATE_CHIVEMENT_BY_CLASS); for(int i =0;iInt(1, examVo.getClassExam()[i]); ps.setInt(2, examVo.getSid()[i]); ps.setInt(3, examVo.getC_id()); ps.executeUpdate(); } } catch (SQLException e) { e.printStackTrace(); } } /** * 全部查询获得行数 * * @return */ public int getnumberAll(String str) { int number = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(str); rs = ps.executeQuery(); rs.next(); number = rs.getInt(1); // rs.close(); // ps.close(); // conn.close(); } catch (SQLException e) { e.printStackTrace(); } return number; } /** * 根据学号根据组号根据课程号查询获得行数 * * @return */ public int getnumber(String str, int i) { int number = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(str); ps.setInt(1, i); rs = ps.executeQuery(); rs.next(); number = rs.getInt(1); // rs.close(); // ps.close(); // conn.close(); } catch (SQLException e) { e.printStackTrace(); } return number; } /** * 根据姓名课程名查询获得行数 * */ public int getnumberByName(String str, String i) { int number = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(str); ps.setString(1, i); ps.setString(2, "%" + i + "%"); ps.setString(3, "%" + i); ps.setString(4, i + "%"); rs = ps.executeQuery(); rs.next(); number = rs.getInt(1); } catch (SQLException e) { e.printStackTrace(); } return number; } // /** // * 根据课程名查询获得行数 // * // */ // // public int getnumberByClassName(String str, String i) { // int number = 0; // PreparedStatement ps = null; // ResultSet rs = null; // try { // ps = conn.prepareStatement(str); // ps.setString(1, i); // ps.setString(2, "%" + i + "%"); // ps.setString(3, "%" + i); // ps.setString(4, i + "%"); // rs = ps.executeQuery(); // rs.next(); // number = rs.getInt(1); // } catch (SQLException e) { // e.printStackTrace(); // } // return number; // } /** * * 根据课程名修改成绩获得行数 * * @param str * @param i * @return */ public int getnumberBySelectClassName(String str, int i) { int number = 0; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(str); ps.setInt(1, i); rs = ps.executeQuery(); rs.next(); number = rs.getInt(1); } catch (SQLException e) { e.printStackTrace(); } return number; } }

数据库的rs.getInt(1)是什么意思？？ ResultSet rs = null; rs = st.executeQuery(sql); rs:数据集。 rs.getInt(int index); rs.getInt(String columName); 你可以通过索引或者列名来获得查询结果集中的某一列的值。 public Goods findGoodsById(int id) { ...

对于数据库自增id（通常非空、数字类型）：推荐使用e.setId(rs.getInt(1))：更简洁、高效，且符合自增id非空的特性（前提是实体类id为int类型）。若实体类id定义为Integer类型，可使用e.setId(rs.getInt(1))（自动装箱为Integer），或e.setId(rs.getObject(1, Integer.class))（更直接的包装类型获取方式）。

前段时间在Myeclipse导入一个项目，在list2.add(rs.getInt(1));出现了错误，add中不能加入int方法如下：解决的办法如下：将List list2=new ArrayList();修改成List list = new ArrayList();后按住ctrl+1,将JER转换成1.5后即可解决问题：楼主QQ：496056171

JDBC ResultSet 的getInt, getLong, getDouble, getFloat等方法，不论数据库中是否存储为null，都返回0，或者0.0。那如何才能返回null呢? 我个人是加上判断，代码如下： ResultSet rs = statement.executeQuery("select Id from table"); Integer id =

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