记录2

 

spring web 项目实战系列--搭建一个仿知乎的问答网站（二）

目录(?)[+]

1. 传送门

spring web 项目实战系列–搭建一个仿知乎的问答网站（一）

spring web 项目实战系列–搭建一个仿知乎的问答网站（二)

spring web 项目实战系列–搭建一个仿知乎的问答网站（三）

spring web 项目实战系列–搭建一个仿知乎的问答网站（四）

spring web 项目实战系列–搭建一个仿知乎的问答网站（5） 拦截器页面访问控制 
项目工程地址： https://code.csdn.net/zhyh1435589631/my_zhihu/tree/master 
这次主要更新数据表设计与测试

2. 项目分析

1. 首先我们这个项目， 主要涉及到用户， 问题， 回答， 用户状态管理， 因而， 我们初步设想是需要建立 4 张数据表， 用来存储相关信息

2.1 用户表

表项功能描述id主键username用户名password密码salt密码盐噪声headUrl头像url

这里需要说明的是： 
1.salt 字段， 主要是用来记录用户密码所添加的随机盐信息。

1. 明文密码保存的时候， 当数据库被黑客脱裤的时候， 容易发生密码泄露， 造成非常不好的影响， 因而这里引入了盐的机制2. 在flask 中 使用 Werkzeug 模块用来实现密码散列， 并提供了两种方法： generate_password_hash 和 check_password_hash， 虽然没有看过他的底层， 不过感觉上， 实现原理和我们这里使用的加盐技术是类似的

2.数据表创建代码：

<code class="hljs sql has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">drop</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TABLE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">EXISTS</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">`user`</span>;</span><span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">create</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TABLE</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">`user`</span> (  id <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">PRIMARY</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">KEY</span> AUTO_INCREMENT,  username <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">VARCHAR</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">45</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">UNIQUE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>,  password <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">VARCHAR</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">128</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>,  salt <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">VARCHAR</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">128</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>,  headUrl <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">VARCHAR</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">256</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>) CHARSET = utf8 ENGINE = innodb;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>

2.2 问题表

表项功能描述id主键userId用户对应的在user 表中的idtitle问题的标题content问题的内容createdDate问题的创建时间commentCount问题的评论数

这里需要说明的是， 这个 commentCount 字段， 看上去是冗余的， 但是如果我们每次需要查看这个评论数信息的时候， 都 对另一个回答表做查询操作， 感觉性能上不是特别理想， 于是考虑引入冗余， 提高性能。

<code class="hljs sql has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">drop</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TABLE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">EXISTS</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">`question`</span>;</span><span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">create</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TABLE</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">`question`</span>(  id <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">PRIMARY</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">KEY</span> AUTO_INCREMENT,  userId <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,  title <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">VARCHAR</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">128</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>,  content <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">VARCHAR</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">512</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>,  createdDate DATETIME <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span>,  commentCount <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>) CHARSET = utf8 ENGINE = innodb;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>

2.3 回答表

表项功能描述id主键userId用户对应的在user 表中的idquestionId对应的问题的idcontent回答的内容createdDate回答的创建时间

<code class="hljs sql has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DROP</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TABLE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">IF</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">EXISTS</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">`answer`</span>;</span><span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">create</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">table</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">`answer`</span>(  id <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">PRIMARY</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">KEY</span> AUTO_INCREMENT,  userId <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,  questionId <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,  content <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">VARCHAR</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">512</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>,  createdDate DATETIME <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span>) CHARSET = utf8 ENGINE = innodb;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>

2.4 用户登陆状态表

表项功能描述id主键ticket用户对应的唯一身份标识status登陆状态信息userId相应的用户expiredDate会话过期时间

这里需要说明的是： 
1. 这个ticket 表， 非常类似于我们存储在服务器上的session 
2. 我们知道 http 协议是无状态协议， 也就是说， 任何人都可以向服务器发送请求， 那么服务器为了区分不同的用户， 需要使用session用来存储当前会话的用户信息， 而在客户端反应为 cookie。当客户端请求过来的时候， 如果是首次访问， 此时没有携带任何cookie信息， 那么服务器向客户端返回的时候， 会添加一个 set-cookie 的字段， 用来向客户端传递一个cookie， 下次用户在访问这个网站的时候， 需要将这个cookie的信息加上， 网站服务器接收到这个请求后找到这个cookie， 提取其中的信息， 即可判断当前的用户信息了。 
3. 在我们的服务器端， 通过数据库表存储这个ticket， 本质上， 一些大型的网站， 使用通用账户登陆的时候， 底层也差不多就是这么一个原理了。

<code class="hljs sql has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DROP</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TABLE</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">IF</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">EXISTS</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">`ticket`</span>;</span><span class="hljs-operator" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">create</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">TABLE</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">`ticket`</span>(  id <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">PRIMARY</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">KEY</span> AUTO_INCREMENT,  ticket <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">VARCHAR</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">128</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">''</span>,  status <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,  userId <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">INTEGER</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">DEFAULT</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>,  expiredDate DATETIME <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NOT</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">NULL</span>) CHARSET = utf8 ENGINE = innodb;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>

3. 数据库配置

1. 首先一定搭建一个mysql的环境， 这个就不再多说了， 因为我这边已经配置完毕了， 大家可以参考官网的说明进行配置http://dev.mysql.com/doc/refman/5.7/en/

3.1 在spring 项目中引入 mybatis

1. 首先需要说明一下， mybatis 实际上是一个数据库的框架， 使用他可以简化 数据库的操作流程， 使得用户可以更多的关注到数据库的核心操作上面， 不用像jdbc 一样进行各种复杂的操作。

2. 在 resources 目录下加入 文件 mybatis-config.xml 用来配置mybatis

   <code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-pi" style="color: rgb(0, 102, 102); box-sizing: border-box;"><?xml version="1.0" encoding="UTF-8"?></span><span class="hljs-doctype" style="color: rgb(102, 0, 102); box-sizing: border-box;"><!DOCTYPE configuration        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"        "http://mybatis.org/ dtd/mybatis-3-config.dtd"></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">configuration</span>></span>    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">settings</span>></span>        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"><!-- Globally enables or disables any caches configured in any mapper under this configuration --></span>        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">setting</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">name</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"cacheEnabled"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">value</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"true"</span>/></span>        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"><!-- Sets the number of seconds the driver will wait for a response from the database --></span>        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">setting</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">name</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"defaultStatementTimeout"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">value</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"3000"</span>/></span>        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"><!-- Enables automatic mapping from classic database column names A_COLUMN to camel case classic Java property names aColumn --></span>        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">setting</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">name</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"mapUnderscoreToCamelCase"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">value</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"true"</span>/></span>        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"><!-- Allows JDBC support for generated keys. A compatible driver is required.        This setting forces generated keys to be used if set to true,         as some drivers deny compatibility but still work --></span>        <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">setting</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">name</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"useGeneratedKeys"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">value</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"true"</span>/></span>    <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">settings</span>></span>    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"><!-- Continue going here --></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">configuration</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li></ul>

   

3. 配置application.properties 
   添加mysql 数据库的连接信息 
   

3.2 创建数据库表对象（以User 表为例）

1. 这时候， 我们就需要创建数据库的表对象了 
    
   如图在model文件夹中建立数据对象的类， 如 User 
   ps： 注意使用 @Mapper 注解

   <code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">@Mapper<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> User {    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> id;    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> String username;    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> <span class="hljs-title" style="box-sizing: border-box;">getId</span>() {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> id;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setId</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> id) {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.id = id;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> String <span class="hljs-title" style="box-sizing: border-box;">getUsername</span>() {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> username;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setUsername</span>(String username) {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.username = username;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> String <span class="hljs-title" style="box-sizing: border-box;">getPassword</span>() {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> password;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setPassword</span>(String password) {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.password = password;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> String <span class="hljs-title" style="box-sizing: border-box;">getSalt</span>() {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> salt;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setSalt</span>(String salt) {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.salt = salt;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> String <span class="hljs-title" style="box-sizing: border-box;">getHeadUrl</span>() {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> headUrl;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setHeadUrl</span>(String headUrl) {        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.headUrl = headUrl;    }    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> String password;    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> String salt;    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> String headUrl;}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li></ul>

2. 在dao 中建立 UserDAO 用来访问 User 
   需要说明的是， UserDAO 是一个接口， 也需要使用 @Mapper 进行注解， 相关的语法可以参考mybatis 的官方文档：http://www.mybatis.org/mybatis-3/zh/

   <code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/** * Created by ThinkPad User on 2016/7/22. */</span><span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Mapper</span><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">interface</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">UserDAO</span> {</span>    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> String INSERT_FIELDS = <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" username, password, salt, headUrl "</span>;    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> String TABLE_NAME = <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" user "</span>;    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> String SELECT_FIELDS = <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" id, "</span> + INSERT_FIELDS;    <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Insert</span>({<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"insert into "</span>, TABLE_NAME, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" ( "</span>,            INSERT_FIELDS, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" ) values (#{username}, #{password}, #{salt}, #{headUrl})"</span>})    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> addUser(User user);    <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Select</span>({<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"select "</span>, SELECT_FIELDS, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" from "</span>, TABLE_NAME,            <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">" where id = #{id}"</span>})    User selectById(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> id);}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li></ul>

3. 下面需要编写测试用例

   <code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/** * Created by ThinkPad User on 2016/7/22. */</span><span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@RunWith</span>(SpringJUnit4ClassRunner.class)<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@SpringApplicationConfiguration</span>(classes = DemoApplication.class)<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@WebAppConfiguration</span><span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Sql</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"/create_database.sql"</span>)<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">UserTest</span> {</span>    <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Autowired</span>    UserDAO userDAO;<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//    @Autowired</span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//    User user;</span>    <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Test</span>    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 主要用来测试插入和 选择功能</span>    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">insertTest</span>(){        User user = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> User();        Random random = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Random();        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>; i != <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>; i++){            user.setUsername(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"User"</span> + i);            user.setPassword(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"password"</span> + i);            user.setSalt(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"salt"</span> + i);            user.setHeadUrl(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"/static/yurisa/"</span> + random.nextInt(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>) + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">".jpg"</span>);            userDAO.addUser(user);        }        user = userDAO.selectById(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>);        Assert.assertNotNull(user);    }}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right: 1px solid rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li></ul>

4. 类似的可以配置其他几个数据表对象， 及其测试用例

3.3 感受

写这部分的时候， 最大的收获是， 一定要写测试用例， 因为太容易出错了， 还是 flask-sqlalchemy 中的 orm 模型好用啊

4. 遇到的一些问题

1. 
   主要原因是， 用错注解了， 这里controller 应该使用 @Controller 注解 
   

2. 
   主要原因是， 我们自动装配 user， 可以又在后面为 user 分配空间， 导致错误

3. 
   这个主要是 我们创建数据库， 而没有选择数据库导致的错误

4. 
   数据库对象中 DATETIME 没有now（）方法

5. 
   测试的时候， 忘记写 addQuestion 方法， 导致数据库中没有数据

5. 小结

使用java web开发， 总的感觉是， 好费劲， 可能是不太熟悉java 和 spring 的原因把， 反正越写越觉得 python 的flask 框架好用多了。。。