mybatis 一對一關聯 association 返回空值

最近學習spring mvc + mybatis開發，看的書是《Spring MVC+Mybatis開發 從入門到精通》，在學習一對一關聯，並且延遲加載一節的時候，使用書上講解的例子無法調通，主要代碼問題是在mapper.xml文件中，部分如下：

    <resultMap id="BaseResultMap" type="com.pp.entity.SysUser">
        
        <id column="F_Id" jdbcType="VARCHAR" property="fId" />
        <result column="F_Account" jdbcType="VARCHAR"
            property="fAccount" />
        <result column="F_RealName" jdbcType="VARCHAR"
            property="fRealname" />
        <result column="F_NickName" jdbcType="VARCHAR"
            property="fNickname" />
        <result column="F_HeadIcon" jdbcType="VARCHAR"
            property="fHeadicon" />
        <result column="F_Gender" jdbcType="TINYINT" property="fGender" />
        <result column="F_Birthday" jdbcType="TIMESTAMP"
            property="fBirthday" />
        <result column="F_MobilePhone" jdbcType="VARCHAR"
            property="fMobilephone" />
        <result column="F_Email" jdbcType="VARCHAR" property="fEmail" />
        <result column="F_WeChat" jdbcType="VARCHAR" property="fWechat" />
        <result column="F_ManagerId" jdbcType="VARCHAR"
            property="fManagerid" />
        <result column="F_SecurityLevel" jdbcType="INTEGER"
            property="fSecuritylevel" />
        <result column="F_Signature" jdbcType="VARCHAR"
            property="fSignature" />
        <result column="F_OrganizeId" jdbcType="VARCHAR"
            property="fOrganizeid" />
        <result column="F_DepartmentId" jdbcType="VARCHAR"
            property="fDepartmentid" />
        <result column="F_RoleId" jdbcType="VARCHAR" property="fRoleid" />
        <result column="F_DutyId" jdbcType="VARCHAR" property="fDutyid" />
        <result column="F_IsAdministrator" jdbcType="TINYINT"
            property="fIsadministrator" />
        <result column="F_SortCode" jdbcType="INTEGER"
            property="fSortcode" />
        <result column="F_DeleteMark" jdbcType="TINYINT"
            property="fDeletemark" />
        <result column="F_EnabledMark" jdbcType="TINYINT"
            property="fEnabledmark" />
        <result column="F_Description" jdbcType="VARCHAR"
            property="fDescription" />
        <result column="F_CreatorTime" jdbcType="TIMESTAMP"
            property="fCreatortime" />
        <result column="F_CreatorUserId" jdbcType="VARCHAR"
            property="fCreatoruserid" />
        <result column="F_LastModifyTime" jdbcType="TIMESTAMP"
            property="fLastmodifytime" />
        <result column="F_LastModifyUserId" jdbcType="VARCHAR"
            property="fLastmodifyuserid" />
        <result column="F_DeleteTime" jdbcType="TIMESTAMP"
            property="fDeletetime" />
        <result column="F_DeleteUserId" jdbcType="VARCHAR"
            property="fDeleteuserid" />
        <result column="F_CardNo" jdbcType="VARCHAR" property="fCardno" />
        <association property="userLogon"
            javaType="com.pp.entity.SysUserLogon" select="findSysUserLogonById"
            column="F_Id">
        </association>
    </resultMap>

<!-- 加載sysuserlogon -->
    <select id="findSysUserLogonById"
        resultType="com.pp.entity.SysUserLogon"
        parameterType="java.lang.String">
        select
        *
        from sys_userlogon
        where F_UserId = #{value}
    </select>

sys_user 表和 sys_userlogon 表的關系是 

sys_user.f_id = sys_userlogon.f_userid

一對一關聯使用的是association配置，property指向sys_user實體類的userLogon屬性，如下：

 <association property="userLogon"
            javaType="com.pp.entity.SysUserLogon" select="findSysUserLogonById"
            column="F_Id">
        </association>

關聯的sql語句id是 findSysUserLogonById ，具體結構如下：

 <select id="findSysUserLogonById"
        resultType="com.pp.entity.SysUserLogon"
        parameterType="java.lang.String">
        select
        *
        from sys_userlogon
        where F_UserId = #{value}
    </select>

 

調試過程中在控制台中確實看到了延遲加載執行的sql是正常的，但是SysUser實體中的 userLogon卻始終為null

懷疑是兩個類某些字段的屬性存在相同命名的問題，但是覺得不應該如此low，但還是試着在association節中單獨加上result節聲明，如下：

<association property="userLogon"
            javaType="com.pp.entity.SysUserLogon" select="findSysUserLogonById"
            column="F_Id">
            <id column="F_Id" property="fId" jdbcType="VARCHAR" />
            <result column="F_UserId" property="fUserid"
                jdbcType="VARCHAR" />
            <result column="F_UserPassword" property="fUserpassword"
                jdbcType="VARCHAR" />
            <result column="F_UserSecretkey" property="fUsersecretkey"
                jdbcType="VARCHAR" />

        </association>

結果依然不行，后來參考網上相同問題的答案，單獨增加一個resultMap，修改 findSysUserLogonById的select配置節，將resultType=“com.pp.entity.SysUserLogon”去掉，換成resultMap=“（新定義的SysUserLogon的resultMap名）”，代碼如下：

<resultMap id="userLogonMap"
        type="com.pp.entity.SysUserLogon">

        <id column="F_Id" property="fId" jdbcType="VARCHAR" />
        <result column="F_UserId" property="fUserid" jdbcType="VARCHAR" />
        <result column="F_UserPassword" property="fUserpassword"
            jdbcType="VARCHAR" />
        <result column="F_UserSecretkey" property="fUsersecretkey"
            jdbcType="VARCHAR" />
        <result column="F_AllowStartTime" property="fAllowstarttime"
            jdbcType="TIMESTAMP" />
        <result column="F_AllowEndTime" property="fAllowendtime"
            jdbcType="TIMESTAMP" />
        <result column="F_LockStartDate" property="fLockstartdate"
            jdbcType="TIMESTAMP" />
        <result column="F_LockEndDate" property="fLockenddate"
            jdbcType="TIMESTAMP" />
        <result column="F_FirstVisitTime" property="fFirstvisittime"
            jdbcType="TIMESTAMP" />
        <result column="F_PreviousVisitTime"
            property="fPreviousvisittime" jdbcType="TIMESTAMP" />
        <result column="F_LastVisitTime" property="fLastvisittime"
            jdbcType="TIMESTAMP" />
        <result column="F_ChangePasswordDate"
            property="fChangepassworddate" jdbcType="TIMESTAMP" />
        <result column="F_MultiUserLogin" property="fMultiuserlogin"
            jdbcType="TINYINT" />
        <result column="F_LogOnCount" property="fLogoncount"
            jdbcType="INTEGER" />
        <result column="F_UserOnLine" property="fUseronline"
            jdbcType="TINYINT" />
        <result column="F_Question" property="fQuestion"
            jdbcType="VARCHAR" />
        <result column="F_AnswerQuestion" property="fAnswerquestion"
            jdbcType="VARCHAR" />
        <result column="F_CheckIPAddress" property="fCheckipaddress"
            jdbcType="TINYINT" />
        <result column="F_Language" property="fLanguage"
            jdbcType="VARCHAR" />
        <result column="F_Theme" property="fTheme" jdbcType="VARCHAR" />

    </resultMap>
    <!-- 加載sysuserlogon -->
    <select id="findSysUserLogonById" resultMap="userLogonMap"
        parameterType="java.lang.String">
        select
        *
        from sys_userlogon
        where F_UserId = #{value}
    </select>

這樣調整之后，association關聯的對象不再為null