diff --git a/CommentDao.xml b/CommentDao.xml
new file mode 100644
index 0000000..22f9f32
--- /dev/null
+++ b/CommentDao.xml
@@ -0,0 +1,53 @@
+<?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">
+<mapper namespace="com.forum.dao.CommentDao">
+
+
+    <resultMap id="comment" type="Comment">
+        <id property="id" column="cid"/>
+        <result property="username" column="username"/>
+        <result property="email" column="email"/>
+        <result property="content" column="content"/>
+        <result property="userComment" column="usercomment"/>
+        <result property="avatar" column="avatar"/>
+        <result property="createTime" column="create_time"/>
+        <result property="forumId" column="forum_id"/>
+        <association property="forum" javaType="Forum">
+            <id property="id" column="id"/>
+        </association>
+    </resultMap>
+    <delete id="delById">
+        delete from comment where id=#{id}
+    </delete>
+
+    <select id="findByForumIdAndParentCommentNull" resultMap="comment">
+        select c.id cid,c.username,c.email,c.content,c.avatar,
+        c.create_time,c.forum_id,c.parent_comment_id
+        from comment c, forum b
+        where c.forum_id = b.id and c.forum_id = #{forumId}
+        order by c.create_time desc
+    </select>
+
+
+    <insert id="saveComment" parameterType="Comment">
+        insert into comment (username,email,content,avatar,
+        create_time,forum_id,parent_comment_id, usercomment)
+        values (#{username},#{email},#{content},#{avatar},
+        #{createTime},#{forumId},#{parentCommentId}, #{userComment});
+    </insert>
+
+
+    <select id="findByParentCommentId" resultMap="comment">
+        select c.id cid, c.username, c.email, c.content, c.avatar,
+        c.create_time, c.forum_id, c.parent_comment_id
+        from comment c
+        where c.parent_comment_id = #{parentCommentId}
+    </select>
+
+    <select id="getAllComment" resultType="com.forum.entity.Comment">
+        select id,username,email,content,create_time from comment
+    </select>
+
+</mapper>