通过jdbc对数据库操作

package swingWeChat;

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

public class JDBCdemo {
    private static final String URL="jdbc:mysql://192.168.1.118:3306/person";
    private static final String USER = "root";
    private static final String PWD = "root";
    private static Connection conn;

    public static void main(String[] args) throws Exception {
        //加载驱动
        Class.forName("com.mysql.jdbc.Driver");//导入jar包的class驱动文件
        //获得数据连接对象
         conn=DriverManager.getConnection(URL,USER,PWD);
        //准备声明对象，输入sql语句
         select();
         selectFrom();
         add();
//       update();
//       delete();


    }
    //查询全部
    public static void select() throws Exception{
        System.out.println("查询表中全部内容");
        String sql="select *from user;";
        PreparedStatement ps=conn.prepareStatement(sql);
        //执行查询
        ResultSet rs=ps.executeQuery();
        while(rs.next()){
            System.out.println("id:"+rs.getString("id")+"，"
                    + "name="+rs.getString("name")+"，sex="+rs.getString("sex"));
        }
        System.out.println("*************************************");
    }
    //按条件查询：
    public static void selectFrom() throws Exception{
        System.out.println("查询表中指定属性内容");
        String sql="select *from user where id=2342";
        PreparedStatement ps=conn.prepareStatement(sql);
        ResultSet rs=ps.executeQuery();
        while(rs.next()){
            System.out.println(rs.getString("id")+","+rs.getString("name"));
        }
        System.out.println("*************************************");
    }
    //添加
    public static void add() throws Exception{
        System.out.println("向表中添加内容");
        String sql="insert into user (id,name,pwd,sex,xl) values (?,?,md5(?),?,?)";
        PreparedStatement ps=conn.prepareStatement(sql);
        ps.setString(1, "9999");
        ps.setString(2, "Shorlock");
        ps.setString(3, "homes");
        ps.setString(4, "男");
        ps.setString(5, "本科");
        boolean b=ps.execute();
        if(b==false){
            System.out.println("添加成功");
            JDBCdemo.select();
        }
        System.out.println("*************************************");
    }
    //修改数据库
    public static void update() throws Exception{
        System.out.println("修改表中指定内容");
        String sql="update user set name=?,sex=?,xl=?,pwd=md5(?) where id=?";
        PreparedStatement ps=conn.prepareStatement(sql);
        ps.setString(1, "Shorlock");
        ps.setString(2, "男");
        ps.setString(3, "研究生");
        ps.setString(4, "sql123");
        ps.setString(5, "9999");
        boolean a=ps.execute();
        if(a==false){
            System.out.println("修改成功");
        }
        JDBCdemo.select();
        System.out.println("*************************************");
    }
    //删除表中指定内容
    public static void delete() throws Exception{
        String sql="delete from user where id=?and name=?";
        PreparedStatement ps=conn.prepareStatement(sql);
        ps.setString(1, "9999");
        ps.setString(2, "Shorlock");
        boolean b=ps.execute();
        if(b==false){
            System.out.println("删除成功");
        }
        JDBCdemo.select();
        System.out.println("*************************************");
    }

}