一、JdbcTemplate操作数据库-单条数据

1、调用 JdbcTemplate 方法实现查询表 记录数

  // 查询
    @Override
    public int selectCount() {
   
        // 1创建sql语句
        String sql = "select count(*) from t_user";
        int count = jdbcTemplate.queryForObject(sql, Integer.class);
        return count;
    }

测试

 // 查询
    @Test
    public void query() {
   
        ApplicationContext context =
                new ClassPathXmlApplicationContext("bean1.xml");
        UserService userService = context.getBean("userService", UserService.class);
        int count = userService.findCount();
        System.out.println("表记录数"+count);
    }

2、调用 JdbcTemplate 方法实现查询返回对象

UserDaoImpl.java

  @Override
    public User findUserInfo(String id) {
   
        // 1创建sql语句
        String sql = "select * from t_user where userid=?";
        User user = jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class),id);
        return user;
    }

// 查询