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);