Mybatis selectKey标签的keyProperty属性报错，关键字间隔不能有空格

源代码片段：

1 <insert id="addAdminAction" parameterType="x.x.x.RoleVo">
2     <selectKey keyProperty="idRole, createdDate" resultType="x.x.x.RoleVo" order="BEFORE">
3        select getid() idRole, to_char(sysdate, 'yyyy-mm-dd hh24:mi:ss') createdDate from dual 
4     </selectKey>
5     <!-- insert sql--> 
6 </insert>

报错内容：

1 org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.executor.ExecutorException: Error selecting key or setting result to parameter object. Cause: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named ' createdDate' in 'class x.x.x.RoleVo'

原因：当keyProperty有多个目标列时，列关键字之间用逗号","分隔，并且不应有多余空格（即keyProperty="idRole, createdDate"间不应该有空格）。

正确代码片段：

1 <insert id="addAdminAction" parameterType="x.x.x.RoleVo">
2     <selectKey keyProperty="idRole,createdDate" resultType="x.x.x.RoleVo" order="BEFORE">
3        select getid() idRole, to_char(sysdate, 'yyyy-mm-dd hh24:mi:ss') createdDate from dual 
4     </selectKey>
5     <!-- insert sql--> 
6 </insert>

一个空格引起的错误，个人觉得还是挺有意思的