目录场景：一、行转列函数 group_concat(arg)二、分组 group by、count()、sum() 函数的组合使用三、count() 配合 case when then 的使用场景：
I\'m trying to make it so that as long as a user is touching the button, it shows one image, and when the user releases the button, it goes back to a default image.
加载中,请稍侯......