优雅，给我狠狠的优雅
写完了这次大作业真的很感慨。。。将近一个学期的时间几乎大部分都在做这个eBook电子书店。期待答辩好运！
- state和prop的区别：前者动态更新，后者只读。
- setState的异步性：setState之后，数据不是立马生效的，所以后面不要写依赖于这个state的操作
- 父子组件的通讯：具体包括<父亲组件调用子组件的函数，获取子组件的数据 useRef>、<子组件获取父组件的数据，函数调用 传this指针即可>
- Antdesign真的YYDS，省了不少的功夫，组件库YYDS！！！
- 前后端跑通的那一瞬间真的非常惊喜！还有登录做好的瞬间！
- 数据库外键的绑定的时候，需要仔细检查一下类型是不是完全匹配的！
- 级联关系是个不好搞的东西@oneToone，@oneToMany之类的
- ORM映射工具是个很好用的东西，可以通过函数的名字完成SQL的查询
- 后端分页没有做，可惜了，有时间的话做一做一定很不错
- 统计功能是一个很难的功能！对于JPA和ORM映射还有SQL的考查都有体现，方法可以先筛时间，然后根据情况过滤，排序在前端。
- 下订单包括一系列的操作，比如book的销量库存，order/orderItem的操作，总之就是非常多
- 被提问好痛苦。。。
很简单的一次答辩，只需要按照评分标准，几个基本的页面必须要有的，然后要有一个书籍搜索功能，书籍可以在前端把数据写死，然后搜索，难度不大。
涉及到数据库，登录的功能、购物车的东西，其实数据库那一部分老师讲的非常的多，就应该少将一点，然后讲Java后端，最后有多的时间讲数据库。数据库只要有一个基本的概念都能做的很好的功能，感觉等到答辩前再做和早就动工做差别不大，没有必要用SQL语句一点一点的搜索，直接用ORM映射，参考老师给的书店样例，基本看一眼就能学会。
助教会提问，从这次开始得分就不算简单了，助教会根据演示的功能提问，会包含一些上课讲的，所以上课就该好好听。基本会问分层的功能、用途、接口与实现分离的好处，还有java、JavaScript的差别、抽查一个具体的功能点然后完成解释具体的实现，每个层的功能是否明确。
WJS太棒了！！！虽然所有的功能都已经实现了，但是他只要求我演示了两个功能。答辩的时候问的一些也是课程上面讲过的，比较基础的问题，有一个稍微比较难的我没答上了，助教还给我耐心的讲，还安慰我说不要担心，这个可能很多人都答不上来的。当然也没有扣分！好耶！！完结撒花，感谢陪伴！
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