java JDBC 连接数据库

必须先插入工具包

 DataSource ds = JdbcHelper.getDs();
        System.out.println(ds);
        JdbcTemplate jdbcTemplate=new JdbcTemplate(ds);
        System.out.println(jdbcTemplate);
        //新增
        String sql1="insert into biao values(null,?,?,?)";
        int i=jdbcTemplate.update(sql1,"6",6,"6");
        System.out.println(i);
        //删除
        String sql2="delete from biao where id=?";
        int a=jdbcTemplate.update(sql2,"2");
        System.out.println(a);
        //修改
        String sql3="update  biao set name=? where id=2";
        int b=jdbcTemplate.update(sql3,"小军");
        System.out.println(b);
        //查询单个数据
        String sql4="select *from biao where id=?";
        Map<String, Object> stringObjectMap = jdbcTemplate.queryForMap(sql4,3);
        System.out.println(stringObjectMap);
        //查询多个数据
        String sql5="select * from biao where id>?";
        List<Map<String, Object>> maps = jdbcTemplate.queryForList(sql5, 5);
        System.out.println(maps);