和数据库连接的登陆页面及数据的修改查询

package com.wish.wse.dao; import java.sql.*; import java.util.ArrayList; import java.util.List; import com.wish.wse.db.*; import com.wish.wse.model.Myuser; public class TestSQL { public int insertTest(){ Connection conn = null; try { conn = DBConn.getConnection(); String sql = " insert into myuser(id,username,sex) " + " values(?,?,?) "; PreparedStatement stat = conn.prepareStatement(sql); stat.setInt(1, 3); stat.setString(2, "liu"); stat.setString(3, "m"); int flag = stat.executeUpdate(); return flag; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return -1; }finally{ try { DBConn.closeConnection(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public int deleteTest(){ Connection conn = null; try { conn = DBConn.getConnection(); Statement stat = conn.createStatement(); String sql = " delete from myuser where id = 3 "; int flag = stat.executeUpdate(sql); return flag; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return -1; }finally{ try { DBConn.closeConnection(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public int updateTest(){ Connection conn = null; try { conn = DBConn.getConnection(); String sql = " update myuser set username = 'zhangsan',sex = 'f' where id = 1 "; PreparedStatement stat = conn.prepareStatement(sql); int flag = stat.executeUpdate(); return flag; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return -1; }finally{ try { DBConn.closeConnection(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public ArrayList selectTest(){ Connection conn = null; try { conn = DBConn.getConnection(); String sql = " select * from myuser "; PreparedStatement stat = conn.prepareStatement(sql); ResultSet rs = stat.executeQuery(); ArrayList userList = new ArrayList(); while(rs.next()){ Myuser myuser = new Myuser(); myuser.setId(rs.getInt("id")); myuser.setUsername(rs.getString("username")); myuser.setSex(rs.getString("sex")); myuser.setDeptno(rs.getInt("deptno")); myuser.setSal(rs.getFloat("sal")); userList.add(myuser); } return userList; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; }finally{ try { DBConn.closeConnection(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public void transactionTest(Myuser myuser){ Connection conn = null; try { conn = DBConn.getConnection(); String sql = " insert into myuser(id,username,sex,deptno,sal) " + " values(?,?,?,?,?) "; PreparedStatement stat = conn.prepareStatement(sql); //1 stat.setInt(1, myuser.getId()); stat.setString(2, myuser.getUsername()); stat.setString(3, myuser.getSex()); stat.setInt(4, myuser.getDeptno()); stat.setFloat(5, myuser.getSal()); stat.executeUpdate(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { DBConn.closeConnection(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } public static void main(String[] args) { /*TestSQL test = new TestSQL(); ArrayList userList = test.selectTest(); for(int i=0;i<userList.size();i++){ Myuser myuser = (Myuser)userList.get(i); System.out.println(myuser.getId() + " : " + myuser.getUsername()); }*/ TestSQL test = new TestSQL(); //test.deleteTest(); System.out.println(test.deleteTest()); // if(flag==1){ // System.out.println("成功！"); // }else{ // System.out.println("失败！"); // } } }