diff --git a/snailmall-shipping-service/src/main/java/com/njupt/swg/dao/ShippingMapper.xml b/snailmall-shipping-service/src/main/java/com/njupt/swg/dao/ShippingMapper.xml
index 99c7e2a..bef1ff6 100644
--- a/snailmall-shipping-service/src/main/java/com/njupt/swg/dao/ShippingMapper.xml
+++ b/snailmall-shipping-service/src/main/java/com/njupt/swg/dao/ShippingMapper.xml
@@ -1,9 +1,17 @@
-<?xml version="1.0" encoding="UTF-8" ?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
+<!-- 此为MyBatis的Mapper配置文件，namespace属性指定了该Mapper对应的接口全限定名，
+     MyBatis会依据这个namespace将这里定义的SQL语句与对应接口中的方法进行关联，方便调用和映射。
+     这里对应的接口是com.njupt.swg.dao.ShippingMapper，意味着这个文件中的SQL语句是为该接口中定义的方法提供具体实现的 -->
 <mapper namespace="com.njupt.swg.dao.ShippingMapper" >
+  <!-- 定义了一个名为BaseResultMap的结果映射配置，用于将从数据库查询返回的结果集映射到Java对象（具体类型为com.njupt.swg.entity.Shipping）上。
+       通过<constructor>元素来指定构造函数参数与数据库表列之间的映射关系，详细说明了每个列对应的Java类型和JDBC类型等信息，
+       这样MyBatis就能准确地将查询结果中的数据填充到对应的Java对象中 -->
   <resultMap id="BaseResultMap" type="com.njupt.swg.entity.Shipping" >
     <constructor >
       <idArg column="id" jdbcType="INTEGER" javaType="java.lang.Integer" />
+      <!-- 以下每个<arg>元素都对应着Shipping实体类构造函数的一个参数，指定了数据库表列名、对应的JDBC类型以及Java类型，
+           按照顺序依次为user_id、receiver_name等列，用于将查询结果准确地映射到Shipping对象的对应属性上 -->
       <arg column="user_id" jdbcType="INTEGER" javaType="java.lang.Integer" />
       <arg column="receiver_name" jdbcType="VARCHAR" javaType="java.lang.String" />
       <arg column="receiver_phone" jdbcType="VARCHAR" javaType="java.lang.String" />
@@ -17,171 +25,201 @@
       <arg column="update_time" jdbcType="TIMESTAMP" javaType="java.util.Date" />
     </constructor>
   </resultMap>
+  <!-- 定义了一个名为Base_Column_List的SQL片段，包含了一系列数据库表中的列名，这些列名通常是在查询、插入、更新等操作中经常需要用到的。
+       通过定义这个片段，可以在其他SQL语句中方便地复用这些列名，提高代码的可维护性和简洁性 -->
   <sql id="Base_Column_List" >
-    id, user_id, receiver_name, receiver_phone, receiver_mobile, receiver_province, receiver_city, 
-    receiver_district, receiver_address, receiver_zip, create_time, update_time
+    id, user_id, receiver_name, receiver_phone, receiver_mobile, receiver_province, receiver_city,
+        receiver_district, receiver_address, receiver_zip, create_time, update_time
   </sql>
+  <!-- 定义了一个名为selectByPrimaryKey的查询语句，用于根据主键（id）从数据库表（mmall_shipping）中查询记录。
+       resultMap属性指定了使用前面定义的BaseResultMap来将查询结果映射到对应的Java对象（Shipping类型）上，
+       parameterType指定了传入参数的类型为java.lang.Integer，也就是主键的类型，意味着这个查询语句期望接收一个整数类型的主键值作为参数。
+       SQL语句内部通过<include>标签引用了Base_Column_List片段来指定要查询的具体列，然后在where子句中通过#{id,jdbcType=INTEGER}的方式，
+       根据传入的主键值进行筛选，以获取对应主键的记录 -->
   <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
-    select 
+    select
     <include refid="Base_Column_List" />
     from mmall_shipping
     where id = #{id,jdbcType=INTEGER}
   </select>
+  <!-- 定义了一个名为deleteByPrimaryKey的删除语句，用于根据主键（id）从数据库表（mmall_shipping）中删除对应的记录。
+       parameterType指定了传入参数的类型为java.lang.Integer，即主键的类型，表明该删除语句期望接收一个整数类型的主键值作为参数，
+       SQL语句中通过where子句使用#{id,jdbcType=INTEGER}的方式，根据传入的主键值确定要删除的具体记录 -->
   <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
     delete from mmall_shipping
     where id = #{id,jdbcType=INTEGER}
   </delete>
+  <!-- 定义了一个名为insert的插入语句，用于向mmall_shipping表中插入一条新记录，parameterType指定了传入参数的类型为com.njupt.swg.entity.Shipping，
+       意味着这个插入语句期望接收一个Shipping类型的对象作为参数，该对象包含了要插入的各列数据。
+       useGeneratedKeys="true"表示启用数据库自增长主键功能，keyProperty="id"指定了将数据库生成的主键值赋给插入对象的id属性，方便后续获取新插入记录的主键值。
+       SQL语句中明确列出了要插入的各列名以及对应的参数值（通过#{列名,jdbcType=类型}的方式指定参数，如#{id,jdbcType=INTEGER}），
+       对于create_time和update_time列，使用了数据库函数now()来插入当前时间 -->
   <insert id="insert" parameterType="com.njupt.swg.entity.Shipping" useGeneratedKeys="true" keyProperty="id">
-    insert into mmall_shipping (id, user_id, receiver_name, 
-      receiver_phone, receiver_mobile, receiver_province, 
-      receiver_city, receiver_district, receiver_address, 
-      receiver_zip, create_time, update_time
-      )
-    values (#{id,jdbcType=INTEGER}, #{userId,jdbcType=INTEGER}, #{receiverName,jdbcType=VARCHAR}, 
-      #{receiverPhone,jdbcType=VARCHAR}, #{receiverMobile,jdbcType=VARCHAR}, #{receiverProvince,jdbcType=VARCHAR}, 
-      #{receiverCity,jdbcType=VARCHAR}, #{receiverDistrict,jdbcType=VARCHAR}, #{receiverAddress,jdbcType=VARCHAR}, 
-      #{receiverZip,jdbcType=VARCHAR}, now(), now()
-      )
+    insert into mmall_shipping (id, user_id, receiver_name,
+                                receiver_phone, receiver_mobile, receiver_province,
+                                receiver_city, receiver_district, receiver_address,
+                                receiver_zip, create_time, update_time
+    )
+    values (#{id,jdbcType=INTEGER}, #{userId,jdbcType=INTEGER}, #{receiverName,jdbcType=VARCHAR},
+            #{receiverPhone,jdbcType=VARCHAR}, #{receiverMobile,jdbcType=VARCHAR}, #{receiverProvince,jdbcType=VARCHAR},
+            #{receiverCity,jdbcType=VARCHAR}, #{receiverDistrict,jdbcType=VARCHAR}, #{receiverAddress,jdbcType=VARCHAR},
+            #{receiverZip,jdbcType=VARCHAR}, now(), now()
+           )
   </insert>
+  <!-- 定义了一个名为insertSelective的插入语句，相较于前面的insert语句，它更具选择性，只会插入那些非空值的列。
+       通过<trim>标签结合<if>标签来实现动态SQL拼接，<trim>标签用于去除多余的逗号等字符，<if>标签根据传入的Shipping对象的属性是否为null来决定是否添加对应的列和值到SQL语句中。
+       例如，如果Shipping对象的id属性不为null，就会在SQL语句的列部分添加id列，在值部分添加对应的#{id,jdbcType=INTEGER}参数，以此类推，对其他列也进行类似的条件判断插入操作，
+       这样可以更灵活地根据实际传入的对象数据情况进行插入操作，避免插入不必要的null值 -->
   <insert id="insertSelective" parameterType="com.njupt.swg.entity.Shipping" >
     insert into mmall_shipping
     <trim prefix="(" suffix=")" suffixOverrides="," >
-      <if test="id != null" >
+      <if test="id!= null" >
         id,
       </if>
-      <if test="userId != null" >
+      <if test="userId!= null" >
         user_id,
       </if>
-      <if test="receiverName != null" >
+      <if test="receiverName!= null" >
         receiver_name,
       </if>
-      <if test="receiverPhone != null" >
+      <if test="receiverPhone!= null" >
         receiver_phone,
       </if>
-      <if test="receiverMobile != null" >
+      <if test="receiverMobile!= null" >
         receiver_mobile,
       </if>
-      <if test="receiverProvince != null" >
+      <if test="receiverProvince!= null" >
         receiver_province,
       </if>
-      <if test="receiverCity != null" >
+      <if test="receiverCity!= null" >
         receiver_city,
       </if>
-      <if test="receiverDistrict != null" >
+      <if test="receiverDistrict!= null" >
         receiver_district,
       </if>
-      <if test="receiverAddress != null" >
+      <if test="receiverAddress!= null" >
         receiver_address,
       </if>
-      <if test="receiverZip != null" >
+      <if test="receiverZip!= null" >
         receiver_zip,
       </if>
-      <if test="createTime != null" >
+      <if test="createTime!= null" >
         create_time,
       </if>
-      <if test="updateTime != null" >
+      <if test="updateTime!= null" >
         update_time,
       </if>
     </trim>
     <trim prefix="values (" suffix=")" suffixOverrides="," >
-      <if test="id != null" >
+      <if test="id!= null" >
         #{id,jdbcType=INTEGER},
       </if>
-      <if test="userId != null" >
+      <if test="userId!= null" >
         #{userId,jdbcType=INTEGER},
       </if>
-      <if test="receiverName != null" >
+      <if test="receiverName!= null" >
         #{receiverName,jdbcType=VARCHAR},
       </if>
-      <if test="receiverPhone != null" >
+      <if test="receiverPhone!= null" >
         #{receiverPhone,jdbcType=VARCHAR},
       </if>
-      <if test="receiverMobile != null" >
+      <if test="receiverMobile!= null" >
         #{receiverMobile,jdbcType=VARCHAR},
       </if>
-      <if test="receiverProvince != null" >
+      <if test="receiverProvince!= null" >
         #{receiverProvince,jdbcType=VARCHAR},
       </if>
-      <if test="receiverCity != null" >
+      <if test="receiverCity!= null" >
         #{receiverCity,jdbcType=VARCHAR},
       </if>
-      <if test="receiverDistrict != null" >
+      <if test="receiverDistrict!= null" >
         #{receiverDistrict,jdbcType=VARCHAR},
       </if>
-      <if test="receiverAddress != null" >
+      <if test="receiverAddress!= null" >
         #{receiverAddress,jdbcType=VARCHAR},
       </if>
-      <if test="receiverZip != null" >
+      <if test="receiverZip!= null" >
         #{receiverZip,jdbcType=VARCHAR},
       </if>
-      <if test="createTime != null" >
+      <if test="createTime!= null" >
         now(),
       </if>
-      <if test="updateTime != null" >
+      <if test="updateTime!= null" >
         now(),
       </if>
     </trim>
   </insert>
+  <!-- 定义了一个名为updateByPrimaryKeySelective的更新语句，用于根据主键（id）有选择性地更新mmall_shipping表中的记录。
+       通过<set>标签结合<if>标签实现动态SQL拼接，<if>标签根据传入的Shipping对象的各属性是否为null来决定是否添加对应的更新语句到SQL中。
+       例如，如果Shipping对象的userId属性不为null，就会在<set>标签内添加user_id = #{userId,jdbcType=INTEGER}这样的更新语句，以此类推，对其他属性也进行类似判断更新操作，
+       最后通过where子句根据主键值（#{id,jdbcType=INTEGER}）确定要更新的具体记录，这样可以只更新那些有实际值变化的列，避免不必要的全列更新 -->
   <update id="updateByPrimaryKeySelective" parameterType="com.njupt.swg.entity.Shipping" >
     update mmall_shipping
     <set >
-      <if test="userId != null" >
+      <if test="userId!= null" >
         user_id = #{userId,jdbcType=INTEGER},
       </if>
-      <if test="receiverName != null" >
+      <if test="receiverName!= null" >
         receiver_name = #{receiverName,jdbcType=VARCHAR},
       </if>
-      <if test="receiverPhone != null" >
+      <if test="receiverPhone!= null" >
         receiver_phone = #{receiverPhone,jdbcType=VARCHAR},
       </if>
-      <if test="receiverMobile != null" >
+      <if test="receiverMobile!= null" >
         receiver_mobile = #{receiverMobile,jdbcType=VARCHAR},
       </if>
-      <if test="receiverProvince != null" >
+      <if test="receiverProvince!= null" >
         receiver_province = #{receiverProvince,jdbcType=VARCHAR},
       </if>
-      <if test="receiverCity != null" >
+      <if test="receiverCity!= null" >
         receiver_city = #{receiverCity,jdbcType=VARCHAR},
       </if>
-      <if test="receiverDistrict != null" >
+      <if test="receiverDistrict!= null" >
         receiver_district = #{receiverDistrict,jdbcType=VARCHAR},
       </if>
-      <if test="receiverAddress != null" >
+      <if test="receiverAddress!= null" >
         receiver_address = #{receiverAddress,jdbcType=VARCHAR},
       </if>
-      <if test="receiverZip != null" >
+      <if test="receiverZip!= null" >
         receiver_zip = #{receiverZip,jdbcType=VARCHAR},
       </if>
-      <if test="createTime != null" >
+      <if test="createTime!= null" >
         create_time = #{createTime,jdbcType=TIMESTAMP},
       </if>
-      <if test="updateTime != null" >
+      <if test="updateTime!= null" >
         update_time = now(),
       </if>
     </set>
     where id = #{id,jdbcType=INTEGER}
   </update>
+  <!-- 定义了一个名为updateByPrimaryKey的更新语句，用于根据主键（id）更新mmall_shipping表中的记录。
+       该语句会对Shipping对象对应的所有列进行更新，不管传入的对象各属性是否为null，都会将对应列的值更新到数据库表中，
+       通过where子句根据主键值（#{id,jdbcType=INTEGER}）确定要更新的具体记录 -->
   <update id="updateByPrimaryKey" parameterType="com.njupt.swg.entity.Shipping" >
     update mmall_shipping
     set user_id = #{userId,jdbcType=INTEGER},
-      receiver_name = #{receiverName,jdbcType=VARCHAR},
-      receiver_phone = #{receiverPhone,jdbcType=VARCHAR},
-      receiver_mobile = #{receiverMobile,jdbcType=VARCHAR},
-      receiver_province = #{receiverProvince,jdbcType=VARCHAR},
-      receiver_city = #{receiverCity,jdbcType=VARCHAR},
-      receiver_district = #{receiverDistrict,jdbcType=VARCHAR},
-      receiver_address = #{receiverAddress,jdbcType=VARCHAR},
-      receiver_zip = #{receiverZip,jdbcType=VARCHAR},
-      create_time = #{createTime,jdbcType=TIMESTAMP},
-      update_time = now()
+        receiver_name = #{receiverName,jdbcType=VARCHAR},
+        receiver_phone = #{receiverPhone,jdbcType=VARCHAR},
+        receiver_mobile = #{receiverMobile,jdbcType=VARCHAR},
+        receiver_province = #{receiverProvince,jdbcType=VARCHAR},
+        receiver_city = #{receiverCity,jdbcType=VARCHAR},
+        receiver_district = #{receiverDistrict,jdbcType=VARCHAR},
+        receiver_address = #{receiverAddress,jdbcType=VARCHAR},
+        receiver_zip = #{receiverZip,jdbcType=VARCHAR},
+        create_time = #{createTime,jdbcType=TIMESTAMP},
+        update_time = now()
     where id = #{id,jdbcType=INTEGER}
   </update>
-
+  <!-- 定义了一个名为deleteByUserIdShippingId的删除语句，用于根据用户ID（userId）和地址ID（shippingId）从mmall_shipping表中删除对应的记录。
+       parameterType指定了传入参数的类型为map，意味着这个删除语句期望接收一个包含userId和shippingId键值对的Map对象作为参数，
+       SQL语句中通过WHERE子句使用#{userId}和#{shippingId}的方式，根据传入的Map中的对应值确定要删除的具体记录 -->
   <delete id="deleteByUserIdShippingId" parameterType="map">
     DELETE from mmall_shipping WHERE user_id=#{userId} and id = #{shippingId}
   </delete>
-
-    <update id="updateByShipping" parameterType="com.njupt.swg.entity.Shipping">
+  <!-- 定义了一个名为updateByShipping的更新语句，用于根据Shipping对象的相关属性以及主键（id）和用户ID（userId）来更新mmall_shipping表中的记录。
+       该语句会对Shipping对象对应的多个列进行更新，不管传入的对象各属性是否为null，都会将对应列的值更新到数据库表中，
+       通过where子句根据主键值（#{id,jdbcType=INTEGER}）和用户ID值（#{userId,jdbcType=INTEGER}）确定要更新的具体记录 -->
+  <update id="updateByShipping" parameterType="com.njupt.swg.entity.Shipping">
     update mmall_shipping
     set
       receiver_name = #{receiverName,jdbcType=VARCHAR},
@@ -195,14 +233,12 @@
       create_time = #{createTime,jdbcType=TIMESTAMP},
       update_time = now()
     where id = #{id,jdbcType=INTEGER}
-    and user_id = #{userId,jdbcType=INTEGER}
+      and user_id = #{userId,jdbcType=INTEGER}
   </update>
-
+  <!-- 定义了一个名为selectByUserIdShippingId的查询语句，用于根据用户ID（userId）和地址ID（shippingId）从mmall_shipping表中查询对应的记录。
+       parameterType指定了传入参数的类型为map，意味着这个查询语句期望接收一个包含userId和shippingId键值对的Map对象作为参数，
+       resultMap属性指定了使用前面定义的BaseResultMap来将查询结果映射到对应的Java对象（Shipping类型）上，
+       SQL语句中通过<include>标签引用了Base_Column_List片段来指定要查询的具体列，然后在where子句中通过#{userId}和#{shippingId}的方式，
+       根据传入的Map中的对应值进行筛选，以获取符合条件的记录 -->
   <select id="selectByUserIdShippingId" parameterType="map" resultMap="BaseResultMap">
-    SELECT <include refid="Base_Column_List"/> from mmall_shipping where user_id = #{userId} and id = #{shippingId}
-  </select>
-
-  <select id="selectByUserId" parameterType="int" resultMap="BaseResultMap">
-    SELECT <include refid="Base_Column_List"/> from mmall_shipping where user_id = #{userId}
-  </select>
-</mapper>
\ No newline at end of file
+    SELECT <include refid="Base_Column_List"/>
\ No newline at end of file