mybatis简单案例源码详细【注释全面】——Dao层映射文件(UserMapper.xml)【重要】

<?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="org.dao.UserMapper">
	
	<!-- user的resultMap,当数据库字段信息和对象的属性不一样时,需要通过resultMap来映射 -->
	<!--association,property,对应的是实体类对象的名称;resultMap对应的是另一个表的映射  -->
	<resultMap type="Users" id="userList">
		<result property="id" column="id"/>
		<result property="userCode" column="userCode"/>
		<result property="userName" column="userName"/>
		<result property="userPassword" column="userPassword"/>
		<result property="gender" column="gender"/>
		<result property="birthday" column="birthday"/>
		<result property="phone" column="phone"/>
		<result property="address" column="address"/>
		<result property="userrole" column="userrole"/>
		<result property="createBy" column="createBy"/>
		<result property="creationDate" column="creationDate"/>
		<result property="modifyBy" column="modifyBy"/>
		<result property="modifyDate" column="modifyDate"/>
		<association property="role" resultMap="roleList"/>
	</resultMap>

	<!-- Role的resultMap -->
	<resultMap type="Role" id="roleList">
		<result property="id" column="id"/>
		<result property="roleCode" column="roleCode"/>
		<result property="roleName" column="roleName"/>
		<result property="createdBy" column="createdBy"/>
		<result property="creationDate" column="creationDate"/>
		<result property="modifyBy" column="modifyBy"/>
		<result property="modifyDate" column="modifyDate"/>
		
	</resultMap>
	<!-- 查询用户表的记录数 -->
	<select id="count" resultType="int">
		select count(*) from user
	</select>
	
	<!-- 查询所有的用户信息 -->
	<select id="getUserList" resultType="Users">
		select * from user
	</select>
	
	<!-- 根据用户名进行模糊查询 -->
	<select id="getUsersByName" resultMap="userList" parameterType="string">
		select * from user where userName like concat ('%',#{userName},'%')
	</select>
	
	<!-- 查询用户列表 -->
	<select id="getUserListByUser" resultMap="userList" parameterType="Users">
		select * from user where userName like concat('%',#{userName},'%') and userRole = #{userrole}
	</select>
	
	<!-- 查询用户列表,参数是Map集合 -->
	<select id="getUsersListByMap" resultMap="userList" parameterType="Map">
		select * from user where userName like concat ('%',#{userName},'%') and userRole = #{userrole}
	</select>
	
	<!-- 查询用户列表,连接查询-->
	<select id="getUserListAndRole" resultMap="userList" parameterType="Users">
		
	select * from user u join role r on u.userRole = r.id  
		where u.userName like concat ('%',#{userName},'%') and u.userrole = #{userrole}
	</select>
	
	<!-- 增加用户,字段名必须都写上 -->
	<insert id="saveUser" parameterType="Users">
		insert into user (userCode,userName,userPassword,gender,birthday,phone,
								address,userRole,createdBy,creationDate,modifyBy,modifyDate) 
		values(#{userCode},#{userName},#{userPassword},#{gender},#{birthday},#{phone},#{address},#{userrole},#{createBy},#{creationDate},#{modifyBy},#{modifyDate})
	</insert>
	
	<!-- 根据id修改信息 -->
	<update id="updateUser" parameterType="Users">
		update user set userCode=#{userCode},userName=#{userName},userPassword=#{userPassword},gender=#{gender},
						birthday=#{birthday},phone=#{phone},address=#{address},userRole=#{userrole},createdBy=#{createBy},
						creationDate=#{creationDate},modifyBy=#{modifyBy},modifyDate=#{modifyDate}
						where id=#{id}
	</update>
	
	<!-- 根据编号进行删除数据 -->
	<delete id="delUser" parameterType="int">
		delete from user where id=#{id}
	</delete>
	
	<!-- 根据id查询用户列表 -->
	<select id="getUsersById" parameterType="int" resultMap="userList">
		select * from user where id = #{id}
	</select>
	
	<!-- 根据角色id查询用户列表 -->
	<select id="getUsersByRoleId" parameterType="int" resultMap="userList">
		select * from user u,role r where u.userrole = #{userrole} and r.id = u.userrole
	</select>
	
	<!-- 根据用户名和角色编号查询用户信息 -->
	<select id="getUsersListByUserNameAndRole_if" resultMap="userList">
		select * from user u, role r where u.userrole=r.id
		<if test="userrole!=null">
			and userrole = #{userrole}
		</if>
		<if test="userName!=null">
			and userName like concat('%',#{userName},'%')
		</if>
	</select>
	
	<!-- 动态根据用户名和角色id查询用户列表,where and|or -->
	<select id="getUsersListByUserNameAndRole_ifAndwhere" resultMap="userList">
		select * from user 
		<where>
			<if test="userrole!=null and userrole!=''">
				and userrole = #{userrole}
			</if>
			<if test="userName!=null and userName!=''">
				and userName like concat('%',#{userName},'%')
			</if>
		</where>
	</select>
	
	<!-- 动态修改用户信息表if+set -->
	<update id="updateUser_ifAndSet" parameterType="Users">
		update user
		<set>
			<if test="userCode!=null">userCode=#{userCode},</if>
			<if test="userName!=null">userName=#{userName},</if>
			<if test="userPassword!=null">userPassword=#{userPassword},</if>
			<if test="gender!=null">gender=#{gender},</if>
			<if test="birthday!=null">birthday=#{birthday},</if>
			<if test="phone!=null">phone=#{phone},</if>
			<if test="address!=null">address=#{address},</if>
			<if test="userrole!=null">userrole=#{userrole},</if>
			<if test="createBy!=null">createdBy=#{createBy},</if>
			<if test="creationDate!=null">creationDate=#{creationDate},</if>
			<if test="modifyBy!=null">modifyBy=#{modifyBy},</if>
			<if test="modifyDate!=null">modifyDate=#{modifyDate},</if>
		</set>
			where id=#{id}
	</update>
	
	
	<!-- 动态根据用户名和角色id查询用户列表,使用trim进行查询用户信息,where and|or -->
	<!-- prefix:前缀,通过自动识别是否有返回值,在trim包含的内容上加上前缀 -->
	<!-- suffix:后缀,在trim包含的内容的上加上后缀 -->
	<!-- prefixOverrides:对于trim包含的内容的首部进行指定内容 -->
	<!-- suffixOverrides:地狱与trim包含的内容的首尾部进行指定内容的忽略 -->
	<select id="getUsersListByUserNameAndRole_ifAndwhere_trim" resultMap="userList">
		select * from user 
		<trim prefix="where" prefixOverrides="and | or">
			<if test="userrole!=null and userrole!=''">
				and userrole = #{userrole}
			</if>
			<if test="userName!=null and userName!=''">
				and userName like concat('%',#{userName},'%')
			</if>
		</trim>
	</select>
	
	<!-- 动态修改用户信息表if+trim -->
	<update id="updateUser_ifAndTrim" parameterType="Users">
		update user
		<trim prefix="set" suffixOverrides="," suffix="where id=#{id}">
			<if test="userCode!=null">userCode=#{userCode},</if>
			<if test="userName!=null">userName=#{userName},</if>
			<if test="userPassword!=null">userPassword=#{userPassword},</if>
			<if test="gender!=null">gender=#{gender},</if>
			<if test="birthday!=null">birthday=#{birthday},</if>
			<if test="phone!=null">phone=#{phone},</if>
			<if test="address!=null">address=#{address},</if>
			<if test="userrole!=null">userrole=#{userrole},</if>
			<if test="createBy!=null">createdBy=#{createBy},</if>
			<if test="creationDate!=null">creationDate=#{creationDate},</if>
			<if test="modifyBy!=null">modifyBy=#{modifyBy},</if>
			<if test="modifyDate!=null">modifyDate=#{modifyDate},</if>
		</trim>
	</update>
	
	<!-- 根据用户角色列表,获取该角色刘表下用户列表信息foreach_array -->
	<!-- item:循环体中的具体对象。支持属性的点路径访问,如item.age,item.info.details。 具体说明:在list和数组中是其中的对象,在map中是value。该参数为必选。 -->
	<!-- collection:要做foreach的对象,作为入参时,List<?>对象默认用list代替作为键,数组对象有array代替作为键,Map对象没有默认的键。
					当然在作为入参时可以使用@Param("keyName")来设置键,设置keyName后,list,array将会失效。 除了入参这种情况外,还有一种作为参数对象的某个字段的时候。举个例子:
					如果User有属性List ids。入参是User对象,那么这个collection = "ids"
					如果User有属性Ids ids;其中Ids是个对象,Ids有个属性List id;入参是User对象,那么collection = "ids.id"
					上面只是举例,具体collection等于什么,就看你想对那个元素做循环。
					该参数为必选。 -->
	<!-- separator:元素之间的分隔符,例如在in()的时候,separator=","会自动在元素中间用“,“隔开,避免手动输入逗号导致sql错误,如in(1,2,)这样。该参数可选。 -->
	<!-- open:foreach代码的开始符号,一般是(和close=")"合用。常用在in(),values()时。该参数可选。 -->
	<!-- close:foreach代码的关闭符号,一般是)和open="("合用。常用在in(),values()时。该参数可选。 -->
	<!-- index:在list和数组中,index是元素的序号,在map中,index是元素的key,该参数可选。 -->
	<select id="getUsersByRoleId_foreach_array" resultMap="userList">
		select * from user where userrole in 
			<foreach collection="array" item="roleids" open="(" separator="," close=")">
				#{roleids}
			</foreach>
	</select>
	
	<!-- 根据用户角色列表,获取该角色刘表下用户列表信息foreach_list -->
	<select id="getUsersByRoleId_foreach_list" resultMap="userList">
		select * from user where userrole in 
		<foreach collection="list" item="roleids" open="(" separator="," close=")">
			#{roleids}
		</foreach>
	</select>
	
	<!-- 根据用户角色列表和性别(多参数),获取该角色刘表下用户列表信息foreach_map -->
	<select id="getUsersByRoleId_foreach_many_map" resultMap="userList">
		select * from user where gender = #{gender} and  userrole in 
		<foreach collection="roleids" item="roleMap" open="(" separator="," close=")">
			#{roleMap}
		</foreach>
	</select>
	
	<!-- 根据用户角色列表(单参数),获取该角色刘表下用户列表信息foreach_map -->
	<select id="getUsersByRoleId_foreach_one_map" resultMap="userList">
		select * from user where   userrole in 
		<foreach collection="rKey" item="roleMap" open="(" separator="," close=")">
			#{roleMap}
		</foreach>
	</select>
	
	<!-- 查询用户列表,使用choose -->
	<select id="getUsersList_choose" resultMap="userList">
		select * from user where 1=1
			<choose>
				<when test="userName!=null and userName!=''">
					and userName  like concat('%',#{userName},'%')
				</when>
				<when test="userrole!=null">
					and userrole =#{userrole}
				</when>
				<when test="userCode!=null and userCode!=''">
					and userCode =#{userCode}
				</when>
				<otherwise>
					and YEAR(creationDate) = YEAR(#{creationDate})
				</otherwise>
			</choose>
	</select>
	
	<!-- 分页显示用户信息 -->
	<select id="getUserList_page" resultMap="userList">
		select * from user limit #{from},#{pageSize}
	</select>
</mapper>

原文地址:https://www.cnblogs.com/a1111/p/12816143.html