后台数据库的增删改查 项目的

连接数据库的until帮助类

package demo1;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MyDBUtil {
    private static String className = "com.mysql.jdbc.Driver";
    private static String url = "jdbc:mysql://192.168.0.131:9171/sisenmess-user-database";
    public static final String user = "root";  
    public static final String password = "123"; 
    
    
    public static Connection getConnection() throws ClassNotFoundException, SQLException{
        Class.forName(className);
        Connection con = DriverManager.getConnection(url,user,password);
        return con;
    }
    
    public static Statement getStatement(Connection con) throws SQLException{
        Statement st = con.createStatement();
        return st;
    }
    
    public static PreparedStatement getPreparedStatement(Connection con,String sql) throws SQLException{
        PreparedStatement ps = con.prepareStatement(sql);
        return ps;
    }
    
    public static ResultSet getResultSet(Statement st,String sql) throws SQLException{
        ResultSet rs = st.executeQuery(sql);
        /*int rs1 = st.executeUpdate(sql);*/
        return rs;
        
    }
    
    
    public static void closeAllMethod(Connection con,Statement st,ResultSet rs){
          try {
           if(rs!=null){
            rs.close();
           }
           if(st!=null){
            st.close();
           }
           if(con!=null){
            con.close();
           }
          } catch (SQLException e) {
           // TODO 自动生成 catch 块
           e.printStackTrace();
          }
        }

}

项目中的增删改查示例

package demo1;

import java.util.ArrayList;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.sql.*;


public class BuguManger {
    public static void main(String[] args) throws ClassNotFoundException, SQLException, IOException {
        
        BuguManger bugu= new BuguManger();
        //bugu.addBugu();
        //bugu.search();
        //bugu.update();
        bugu.deleteBugu();
    
    }
    public void search() throws ClassNotFoundException, SQLException, IOException{
        //查询数据
                String sql = "";
                Connection con1 = MyDBUtil.getConnection();
                PreparedStatement ps = MyDBUtil.getPreparedStatement(con1, sql);
                
            
                sql = "select * from userlist";
                ResultSet rs1 = ps.executeQuery(sql);
                while(rs1.next()){
                    String uid=rs1.getString(1);
                    String uid2=rs1.getString(2);
                    System.out.println(uid);
                }
    }
    

            
            public void addBugu() throws ClassNotFoundException, SQLException, IOException{
                //增加一条数据
                String sql = "";
                Connection con1 = MyDBUtil.getConnection();
                PreparedStatement ps = MyDBUtil.getPreparedStatement(con1, sql);
                
                InputStreamReader input = new InputStreamReader(System.in);
                BufferedReader br = new BufferedReader(input);
//                System.out.print("请输入用户名：");
//                uname = br1.readLine();
//                System.out.print("请输入密码：");
//                pword = br1.readLine();
//                ps.setString(1, uname);
//                ps.setString(2, pword);
                System.out.print("请输入要添加的姓名：");
                String uname = br.readLine();
//                
//                System.out.print("请输入要添加的密码：");
                String pword = br.readLine();
//                
//                System.out.print("请输入要添加的邮箱：");
                String email = br.readLine();
                sql = "insert into userlist (UserId,UserNo,UserTName) values('"+uname+"','"+pword+"','"+email+"')";
                int rs1 = ps.executeUpdate(sql);
            }
            //修改数据
            public void update() throws ClassNotFoundException, SQLException, NumberFormatException, IOException{
                InputStreamReader input = new InputStreamReader(System.in);
                BufferedReader br = new BufferedReader(input);
                String sql = "";
                Connection con1 = MyDBUtil.getConnection();
                PreparedStatement ps = MyDBUtil.getPreparedStatement(con1, sql);
                System.out.println("请输入你所要修改的编号：");
                int id = Integer.parseInt(br.readLine());
                System.out.println("请输入修改后的名字：");
                String UserNo = br.readLine();
                System.out.println("请输入修改后的密码：");
                String UserTName = br.readLine();
                
                
                sql = "update userlist set UserNo='"+UserNo+"',UserTName='"+UserTName+"'where UserId = '"+id+"'";
                ps.executeUpdate(sql);
                System.out.println("修改成功！");
            }
            //删除数据
            public void deleteBugu() throws ClassNotFoundException, SQLException, NumberFormatException, IOException{
                String sql = "";
                Connection con1 = MyDBUtil.getConnection();
                PreparedStatement ps = MyDBUtil.getPreparedStatement(con1, sql);
                InputStreamReader input = new InputStreamReader(System.in);
                BufferedReader br = new BufferedReader(input);
                System.out.println("请输入你所要删除的编号：");
                int id = Integer.parseInt(br.readLine());
                sql = "delete  from userlist where userId='"+id+"'";
                ps.executeUpdate(sql);
            }
            
            


}