yonghuku.java

这是我写的产品管理系统

package com.yonghuxiaoshou;
import cn.KeKuXiaoShao.*;
import deng.shaoxiao.*;
import sn.ChangPingXiaoShou.*;
import sun.BuMenXiaoShou.*;
import xiao.xiaoshouxiaoshou.*;
import yuan.xiaoshou.*;

//用户连接数据库层这个数据库是用来连接登陆界面的数据库
import java.awt.*;
import java.sql.*;
import java.util.*;

public class YongHuKu{
	//驱动类
	private static final String sDBDriver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
	//连接字符串
	private static final String url = "jdbc:sqlserver://localhost:1433;databasename = XiaoShou";
	//连接姓名
	private static final String user = "zhou";
	//用户名密码
	private static final String pwd = "111111";
	//连接发送方式
	private static PreparedStatement ps = null;
	//定义结果集
	private static ResultSet rs = null;
	
	
	//定义一个方法用来进行连接
	public Connection getconn(){
		Connection conn = null;
		try{
			Class.forName(sDBDriver);
			conn = DriverManager.getConnection(url,user,pwd);
		}
		catch(java.lang.ClassNotFoundException e){
			System.out.println ("找不到文件");
		}
		catch(SQLException e){
			System.out.println ("连接失败");
		}
		return conn;
	}
	//定义一个添加的方法
	public int insert(String T_username,String T_password){
		Connection conn = getconn();
		int num = 0;
		try{
			ps = conn.prepareStatement("insert into t_user(T_username,T_password) values(?,?)");
			ps.setString(1,T_username);
			ps.setString(2,T_password);
			num = ps.executeUpdate();
		}
		catch(SQLException e){
			System.out.println ("添加失败");
		}
		finally{
			try{
				ps.close();
				conn.close();
			}
			catch(SQLException e){
				System.out.println ("t_user添加失败");
			}
		}
		return num;
	}
	//定义一个删除的方法不带参数
	public int delete(){
		Connection conn = getconn();
		int num = 0;
		try{
			ps = conn.prepareStatement("delete from t_user");
			num = ps.executeUpdate();
		}
		catch(SQLException e){
			System.out.println ("删除失败");
		}
		finally{
			try{
				ps.close();
				conn.close();
			}
			catch(SQLException e){
				System.out.println ("t_user删除失败");
			}
		}
		return num;
	}
	//定义一个带参数的删除方法
	public int delete(int T_id){
		Connection conn = getconn();
		int num = 0;
		try{
			ps = conn.prepareStatement("delete from t_user where T_id = ?");
			num = ps.executeUpdate();
		}
		catch(SQLException e){
			System.out.println ("带参数的删除方法失败");
		}
		finally{
			try{
				ps.close();
				conn.close();
			}
			catch(SQLException e){
				System.out.println ("sql带参数的方法删除失败");
			}
		}
		return num;
	}
	//定义一个带参数的查询方法
	public ArrayList select(int T_id){
		Connection conn = getconn();
		ArrayList arr = new ArrayList();
		try{
			ps = conn.prepareStatement("select * from t_user where T_id = ?");
			ps.setInt(1,T_id);
			rs = ps.executeQuery();
			if(rs != null){
				while(rs.next()){
					arr.add(rs.getInt(1));
					arr.add(rs.getString(2));
					arr.add(rs.getString(3));	
				}
			}
		}
		catch(SQLException e){
			System.out.println ("查询失败");
		}
		finally{
			try{
				ps.close();
				conn.close();
			}
			catch(SQLException e){
				System.out.println ("sql查询失败");
			}
		}
		return arr;
	}
	
	//定义一个不带参数的查询方法
	public ArrayList select(){
		Connection conn = getconn();
		ArrayList arr = new ArrayList();
		try{
			ps = conn.prepareStatement("select * from t_user");
			rs = ps.executeQuery();
			if(rs != null){
				while(rs.next()){
					arr.add(rs.getInt(1));
					arr.add(rs.getString(2));
					arr.add(rs.getString(3));
				}
			}
		}
		catch(SQLException e){
			System.out.println ("查询失败");
		}
		finally{
			try{
				ps.close();
				conn.close();
			}
			catch(SQLException e){
				System.out.println ("sql查询失败");
			}
		}
		return arr;
	}	
}