user类

<?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.mapper.UserMapper">

<resultMap id="userMap" type="User"> //user对象映射
<id property="userId" column="user_id" javaType="int"></id>//user的Id
<result property="userName" column="user_name" javaType="string"/> //user的属性
<result property="userMoney" column="user_money" javaType="string"/>
</resultMap>

<resultMap id="userAndInfoMap" type="User">
<id property="userId" column="user_id" javaType="int"></id>
<result property="userName" column="user_name" javaType="string"/>
<result property="userMoney" column="user_money" javaType="string"/>
<!-- <association property="info" resultMap="com.mapper.UserInfoMapper.infoMap" javaType="UserInfo"/> -->　　// user对象包含的对象的配置方式一（user的sql里面写join连接info表）

<association property="info" column="user_id" javaType="UserInfo"　　 //user对象包含的对象的配置方式一（各查各的互补影响）
select ="com.mapper.UserInfoMapper.findUserInfoByUserId"> 
</association>

</resultMap>

<insert id="addUser" parameterType="User">
insert into user values(null,#{user.userName},#{user.userMoney})
</insert>

<delete id="deleteUserByuserId">
delete from user where user_id = #{id}
</delete>

<update id="updateUser" parameterType="User">     //parameterType="User" 表示传递的参数的类型   //id="updateUser"使用的方法名
update user set user_name=#{user.userName},user_money=#{user.userMoney
} where user_id=#{user.userId}
</update>

<select id="selectUserByuserId" resultMap="userAndInfoMap"> 　　// resultMap="userAndInfoMap"返回值的类型，如果返回值是List<UserInfo>也用这个类型
select * from user u left join userInfo i on u.user_id = i.user_id where u.user_id = #{id}
</select>

<select id="findAllUser" resultMap="userMap">
select * from user
</select>

<select id="findUserCount" resultType="int">
select count(*) from user where user_id !=2
</select>

<select id="findUserByuserNameLike" resultMap="userMap">
select * from user where user_name like '%${userName}%'
</select>

</mapper>

　　　　　　　　　　userInfo类

<?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.mapper.UserInfoMapper">

<resultMap id="infoMap" type="UserInfo">//对象映射
<id property="infoId" column="info_id" javaType="int"></id>
<result property="infoName" column="info_name" javaType="string"/>
</resultMap>

<select id="findUserInfoByid" resultMap="infoMap">
select * from userInfo where info_id =#{id}
</select>
<select id="findUserInfoByUserId" resultMap="infoMap">
select * from userInfo where user_id =#{id}
</select>
</mapper>