Mybatis判断map参数是否存在

<select >
    select
    <include ref />
    from sys_user
    where 1=1
    <if test="_parameter.containsKey('sysUserName')">
      and sys_user_name=#{sysUserName}
    </if>
    <if test="_parameter.containsKey('cBeginTime')">
      <![CDATA[
        and create_time >= #{cBeginTime}
      ]]>
    </if>
    <if test="_parameter.containsKey('cEndTime')">
      <![CDATA[
        and create_time < #{cEndTime}
      ]]>
    </if>
    <if test="_parameter.containsKey('uEndTime')">
      <![CDATA[
        and update_time < #{uEndTime}
      ]]>
    </if>
  </select>