diff --git a/swpu-spring-projects-boot/src/main/java/com/swpu/SwpuSpringProjectsApplication.java b/swpu-spring-projects-boot/src/main/java/com/swpu/SwpuSpringProjectsApplication.java
index 27dddf77d565ad6bbc43a8861c913eee9dc18aea..c53fcd7e7c9b12f9384e2384c4ada4c6a4efead6 100644
--- a/swpu-spring-projects-boot/src/main/java/com/swpu/SwpuSpringProjectsApplication.java
+++ b/swpu-spring-projects-boot/src/main/java/com/swpu/SwpuSpringProjectsApplication.java
@@ -1,5 +1,6 @@
 package com.swpu;
 
+import org.mybatis.spring.annotation.MapperScan;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@@ -11,14 +12,16 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
  * <ul>
  *     <li> 1. @SpringBootApplication 注解 代表当前的项目是一个 Spring Boot 项目 </li>
  *     <li> 2. SpringApplication.run(); 代表着 Spring Boot 可运行/可执行 本项目 </li>
+ *     <li> 3. MapperScan 是 MyBatis 整合进 SpringBoot 后，告诉 Spring Boot DAO 存放的位置，这样才能用 Resource 注解来 new 我们的 DAO</li>
  * </ul>
  */
+@MapperScan({"com.swpu.dao.**"})
 @SpringBootApplication
 public class SwpuSpringProjectsApplication {
 
     /**
      * 主函数 仅仅只比我们的 Java-Base-Projects 项目多了一个 Spring 自己的 方法调用
-     * @param args
+     * @param args args
      */
     public static void main(String[] args) {
         SpringApplication.run(SwpuSpringProjectsApplication.class, args);
diff --git a/swpu-spring-projects-boot/src/main/java/com/swpu/controller/SwpuUserController.java b/swpu-spring-projects-boot/src/main/java/com/swpu/controller/SwpuUserController.java
index 29b84f32b1120d1f883b032b899f9d3c4f878818..ea6adc961bfbfe7b9be3f959c19fd3b6a964c813 100644
--- a/swpu-spring-projects-boot/src/main/java/com/swpu/controller/SwpuUserController.java
+++ b/swpu-spring-projects-boot/src/main/java/com/swpu/controller/SwpuUserController.java
@@ -2,9 +2,7 @@ package com.swpu.controller;
 
 import com.swpu.dao.SwpuUserDao;
 import com.swpu.entity.SwpuUserEntity;
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.*;
 
 import javax.annotation.Resource;
 import java.util.List;
diff --git a/swpu-spring-projects-boot/src/main/java/com/swpu/dao/SwpuUserDao.java b/swpu-spring-projects-boot/src/main/java/com/swpu/dao/SwpuUserDao.java
index ebcc2e61bba308a94d45833afe4f3f7483efcf1b..7eb32e913b0fc79b454654e7a32e45380f4615d6 100644
--- a/swpu-spring-projects-boot/src/main/java/com/swpu/dao/SwpuUserDao.java
+++ b/swpu-spring-projects-boot/src/main/java/com/swpu/dao/SwpuUserDao.java
@@ -5,6 +5,17 @@ import org.apache.ibatis.annotations.Param;
 
 import java.util.List;
 
+/**
+ * @author wales
+ * <p>
+ * DAO 是 MyBatis 用作打通 与 XML 中的 SQL 的桥梁
+ * <ul>
+ *     <li> 1. 类名是与 XML 打通的 ID 标识</li>
+ *     <li> 2. 方法名是定位到 XML 中的 SQL</li>
+ *     <li> 3. 方法参数 是 XML 中 SQL 所需的条件参数 </li>
+ *     <li> 4. 方法名前的返回值: 查询(单个返回是 Entity、多个查询是 List<Entity></Entity>); 增加/修改/删除 返回值均为 int ，代表着 增加了多少条数据、修改了多少条数据、删除了多少条数据</li>
+ * </ul>
+ */
 public interface SwpuUserDao {
 
     SwpuUserEntity findById(@Param("id") String id);
diff --git a/swpu-spring-projects-boot/src/main/java/com/swpu/entity/SwpuUserEntity.java b/swpu-spring-projects-boot/src/main/java/com/swpu/entity/SwpuUserEntity.java
index 9c6a0ab0c6cd609ab840540fc076be5d2cc7d461..f4cbb6580b8425e27b77e8bb8c69fbc62884ae18 100644
--- a/swpu-spring-projects-boot/src/main/java/com/swpu/entity/SwpuUserEntity.java
+++ b/swpu-spring-projects-boot/src/main/java/com/swpu/entity/SwpuUserEntity.java
@@ -2,8 +2,11 @@ package com.swpu.entity;
 
 import lombok.Data;
 
-import java.util.Date;
-
+/**
+ * @author wales
+ * <p>
+ * 一个 Entity 对应一个数据库表和表中的字段
+ */
 @Data
 public class SwpuUserEntity {
 
diff --git a/swpu-spring-projects-boot/src/main/resources/application.yml b/swpu-spring-projects-boot/src/main/resources/application.yml
index aa844e56a1fa00386376f024e9bdcf201ab58de8..b2ab5b74edf9966f2a6ffb7e38ae2450d21939c8 100644
--- a/swpu-spring-projects-boot/src/main/resources/application.yml
+++ b/swpu-spring-projects-boot/src/main/resources/application.yml
@@ -1,17 +1,23 @@
 spring:
   application:
     name: swpu-spring-projects
+  # 数据库连接信息
   datasource:
     driver-class-name: com.mysql.cj.jdbc.Driver
     url: jdbc:mysql://localhost:3306/swpu_db
     username: swpu_user
     password: '123456789'
+    # 数据库连接池
     type: com.zaxxer.hikari.HikariDataSource
     hikari:
       maximum-pool-size: 10000
-
-
+# 项目端口
 server:
   port: 20000
+
+# MyBatis XML 配置
 mybatis:
-  mapper-locations:
+  mapper-locations: classpath:mapper/**.xml
+  # 开启 驼峰支持
+  configuration:
+    map-underscore-to-camel-case: true
diff --git a/swpu-spring-projects-boot/src/main/resources/mapper/SwpuUserMapper.xml b/swpu-spring-projects-boot/src/main/resources/mapper/SwpuUserMapper.xml
index b2c568bf83e87931bf03799332a1578de8acbf93..1969466c6d8a65e15863e696debeead8108d0d08 100644
--- a/swpu-spring-projects-boot/src/main/resources/mapper/SwpuUserMapper.xml
+++ b/swpu-spring-projects-boot/src/main/resources/mapper/SwpuUserMapper.xml
@@ -1,8 +1,10 @@
 <!DOCTYPE mapper
         PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<!-- MyBatis 通过 namespace 与 DAO 建立联系 -->
 <mapper namespace="com.swpu.dao.SwpuUserDao">
 
+    <!-- 数据库表中的字段与 Java 实体类型建立映射关系，因为数据库字段命名采用下划线， Java 命名采用驼峰 -->
     <resultMap type="com.swpu.entity.SwpuUserEntity" id="BaseResultMap">
         <id column="id" property="id"/>
         <result column="department_id" property="departmentId"/>
@@ -13,6 +15,7 @@
         <result column="school" property="school"/>
     </resultMap>
 
+    <!-- 查询，关联 DAO 中方法名为 findById 的方法，resultType 对应 DAO 中 findById 方法名前的返回值，parameterType 对应 DAO 中 findById 的参数类型-->
     <select id="findById" resultType="com.swpu.entity.SwpuUserEntity" parameterType="java.lang.String">
         select *
         from swpu_user su
@@ -49,12 +52,13 @@
 
     <update id="update" parameterType="com.swpu.entity.SwpuUserEntity">
         update swpu_user
-        set (
-                department_id = #{departmentId, javaType = Integer},
-                job_level_id = #{jobLevelId, javaType = Integer},
-                pos_id = #{posId, javaType = Integer}, engage_form = #{engageForm, javaType = String},
-                specialty = #{specialty, javaType = String}, school = #{school, javaType = String}
-                )
+        set department_id = #{departmentId, javaType = Integer},
+            job_level_id  = #{jobLevelId, javaType = Integer},
+            pos_id        = #{posId, javaType = Integer},
+            engage_form   = #{engageForm, javaType = String},
+            specialty     = #{specialty, javaType = String},
+            school        = #{school, javaType = String}
+
         where id = #{id, javaType = String}
     </update>