Mybatis 映射文件示例：用户、房间、文件、类别等实体的映射关系

本系统使用 MySQL 数据库，使用关系数据模型。数据库包含以下表格：

用户表 (user)：存储用户的基本信息，包括用户 ID、用户名、密码、性别、年龄、手机号码等字段。
房间表 (room)：存储房间的基本信息，包括房间 ID、房间类型、面积、价格、总数、地址、房间描述等字段。
类别表 (category)：存储房间类型的基本信息，包括类别 ID、类别名称等字段。
文件表 (myfile)：存储上传的文件信息，包括文件 ID、文件标题、文件 URL 等字段。
客户表 (client)：存储客户的基本信息，包括客户 ID、房间 ID、姓名、性别、电话、年龄、地址等字段。

以下展示了对应表格的 Mybatis 映射文件示例：

<?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="cn.smbms.dao.ClientDao">
    <resultMap id="baseResultMap" type="cn.smbms.pojo.Client">
        <result column="id" jdbcType="INTEGER" property="id" />
        <result column="roomId" jdbcType="INTEGER" property="roomId" />
        <result column="name" jdbcType="VARCHAR" property="name" />
        <result column="sex" jdbcType="VARCHAR" property="sex" />
        <result column="phone" jdbcType="VARCHAR" property="phone" />
        <result column="age" jdbcType="VARCHAR" property="age" />
        <result column="addr" jdbcType="VARCHAR" property="addr" />
        <association property="room" javaType="cn.smbms.pojo.Room">
            <result column="roomId"  property="roomId" />
            <result column="price"  property="price" />
            <result column="type"  property="type" />
            <result column="area"  property="area" />
            <result column="total"  property="total" />
            <result column="address"  property="address" />
            <result column="roomDescribe"  property="roomDescribe" />
            <result column="categoryId"  property="categoryId" />
        </association>
    </resultMap>
    <!-- 查询所有 客户-->
    <select id="selectAllClient"  resultMap="baseResultMap">
    		select *   from  client a left join room b on a.roomId=b.roomId
    </select>


    <!--id查询-->
    <select id="selectById" resultType="cn.smbms.pojo.Client">
        select * from  client where id=#{id}
    </select>
    <!--更新-->
    <update id="updClientById" parameterType="cn.smbms.pojo.Client">
    update client set roomId=#{roomId},name=#{name},sex=#{sex},age=#{age},phone=#{phone},addr=#{addr} where id=#{id}
    </update>


    <!--新增-->
    <insert id="insertClient" parameterType="cn.smbms.pojo.Client">
        INSERT INTO client(roomId,name,sex,age,phone,addr)
        VALUES (#{roomId},#{name},#{sex},#{age},#{phone},#{addr})
    </insert>

    <!--前台登录-->
    <select id="LoginClient" parameterType="Client" resultType="cn.smbms.pojo.Client">
    		select *
	        from users
	        where userId=#{userId}
	        and passWord =#{passWord}
    </select>

    <!--前台注册-->
    <insert id="RegisterClient" parameterType="Client">
        INSERT INTO users(userId,passWord)
        VALUES (#{userId},#{passWord})
    </insert>
</mapper>


<?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="cn.smbms.dao.InformationsDao">
    <!--查询-->
    <select id="findInformations"  resultType="cn.smbms.pojo.Informations">
    		select * from smbms_provider
    </select>


</mapper>



<?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="cn.smbms.dao.MyFileDao">

    <insert id="insertFile" parameterType="cn.smbms.pojo.MyFile">
        INSERT INTO myfile(fileTitle,fileUrl)
        VALUES (#{fileTitle},#{fileUrl})
    </insert>

</mapper>




<?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="cn.smbms.dao.RoomDao">
    <resultMap id="baseResultMap" type="cn.smbms.pojo.Room">
        <result column="roomId" jdbcType="INTEGER" property="roomId" />
        <result column="price" jdbcType="VARCHAR" property="price" />
        <result column="type" jdbcType="VARCHAR" property="type" />
        <result column="area" jdbcType="VARCHAR" property="area" />
        <result column="address" jdbcType="VARCHAR" property="address" />
        <result column="total" jdbcType="VARCHAR" property="total" />
        <result column="roomDescribe" jdbcType="VARCHAR" property="roomDescribe" />
        <result column="categoryId" jdbcType="INTEGER" property="categoryId" />
        <association property="category" javaType="cn.smbms.pojo.Category">
            <result column="categoryId"  property="categoryId" />
            <result column="categoryName"  property="categoryName" />
        </association>
    </resultMap>
    <!-- 查询所有 房型-->
    <select id="selectAllRoom" resultMap="baseResultMap">
    		select *   from  room a left join category b on a.categoryId=b.categoryId
    </select>
    <!--删除-->
    <delete id="deleteRoom" parameterType="Integer">
    	 delete from  room where roomId = #{roomId}
	</delete>

    <!--更新-->
    <update id="updRoomById" parameterType="cn.smbms.pojo.Room">
        update room set price=#{price},type=#{type},area=#{area},total=#{total},address=#{address},roomDescribe=#{roomDescribe} where roomId=#{roomId}
    </update>

    <!--id查询-->
    <select id="selectByIdOfVue" resultType="cn.smbms.pojo.Room" parameterType="String">
        select * from  room where roomId=#{roomId}
    </select>
    <!--id查询-->
    <select id="selectById" resultType="cn.smbms.pojo.Room">
        select * from  room where roomId=#{roomId}
    </select>


    <!--新增房型-->
    <insert id="insertRoom" parameterType="cn.smbms.pojo.Room">
        INSERT INTO room(roomId,type,area,price,total,address,roomDescribe)
        VALUES (#{roomId},#{type},#{area},#{price},#{total},#{address},#{roomDescribe})
    </insert>


    <!-- 查询所有房型前端接口-->
    <select id="findAllRoomVue" resultMap="baseResultMap">
    		select *   from  room a left join category b on a.categoryId=b.categoryId
    </select>

    <select id="findRoomVue1" resultType="cn.smbms.pojo.Room">
    		select *   from  room  where categoryId=#{categoryId}
    </select>
    <select id="findRoomVue2" resultType="cn.smbms.pojo.Room">
    		select *   from  room  where categoryId=#{categoryId}
    </select>
    <select id="findRoomVue3" resultType="cn.smbms.pojo.Room">
    		select *   from  room  where categoryId=#{categoryId}
    </select>
    <select id="findRoomVue4" resultType="cn.smbms.pojo.Room">
    		select *   from  room  where categoryId=#{categoryId}
    </select>
    <select id="findRoomVue5" resultType="cn.smbms.pojo.Room">
    		select *   from  room  where categoryId=#{categoryId}
    </select>



</mapper>



<?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="cn.smbms.dao.UserDao">
    <!--  登录-->
    <select id="findUser" parameterType="String" resultType="cn.smbms.pojo.User">
    		select *
	        from user
	        where userName=#{userName}
	        and userPassword =#{userPassword}
    </select>


	<!--判断管理员是否存在-->
	<select id="findUsersByUsername" resultType="cn.smbms.pojo.User">
			select * from user
			where userName=#{userName}
	</select>


	<!--修改密码-->
	<update id="updateUser" parameterType="cn.smbms.pojo.User" >
		update user set userPassword=#{userPassword} where userName=#{userName}
	</update>

</mapper>

这些示例展示了 Mybatis 映射文件的基本结构和常用元素，例如 resultMap、select、insert、update、delete 等，以及如何定义 SQL 语句、参数映射、结果映射等。

希望这些示例可以帮助您理解 Mybatis 映射文件的用法。