JDBC之连接数据库进行增删改查

package com.example.de1;

import org.junit.Test;

import java.sql.*;

public class jdbc {
    private static final String url = "jdbc:mysql://127.0.0.1:3307/test";//默认127.0.0.1:3306，可省，jdbc:mysql:///test
    private static final String user ="root";
    private static final String password ="123";
    @Test
    public void f01() throws SQLException{
        Connection conn = DriverManager.getConnection(url,user,password);//java公司提供的驱动管理类来获得连接,兼容coonection标准。
        System.out.println(conn);
    }
    @Test
    public void f1() throws SQLException {
        Connection conn = DriverManager. getConnection(url, user, password);
        Statement stmt = conn. createStatement();// 执行对象（增删查改）
        //增
        int line = stmt.executeUpdate(  "insert into dept values(50, ' 开发部','南昌')");
        System.out.println(line==1 ? "成功":"失败");
    }
    //增
    @Test
    public void f2() throws SQLException {
        Connection conn = DriverManager. getConnection(url, user, password);
        Statement stmt = conn. createStatement();
        int line = stmt.executeUpdate(  "insert into dept values(60, ' CAIWU','BEIJING')");
        System.out.println(line==1 ? "成功":"失败");
    }
    //删
    @Test
    public void f3() throws SQLException {
        Connection conn = DriverManager. getConnection(url, user, password);
        Statement stmt = conn. createStatement();
        int line = stmt.executeUpdate(  "delete from dept where deptno = 50");
        System.out.println(line==1 ? "成功":"失败");
    }
    //改
    @Test
    public void f4() throws SQLException {
        Connection conn = DriverManager. getConnection(url, user, password);
        Statement stmt = conn. createStatement();
        int line = stmt.executeUpdate(  "update dept set loc='SHANGHAI' where deptno = 60");
        System.out.println(line==1 ? "成功":"失败");
    }
    //查
        @Test
    public void f03() throws SQLException{
        Connection conn = DriverManager.getConnection(url,user,password);
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery("select * from dept where deptno = 10");
         while(rs.next()){
             int id = rs.getInt(1);
        /*   String dname = rs.getString("dname");
             String loc = rs.getString("loc");*/
             Object ob1 =rs.getObject(2);// 利用多态 父类得到子类
             Object ob2 =rs.getObject(3);
             System.out.println(id +" " + ob1 + " " +ob2);
           //  System.out.println(id +" " + dname + " " +loc);
         }


    }
}