title: getSqlSession().selectOne() returns null
body: <p>I am working on mybatis. I am trying to execute below query to get result.</p>
  
  <pre><code>&lt;select id="getMaxSeqNumFromTrans" parameterType="com.abc.ContributionsRequestParamDto" resultType="java.lang.Integer" &gt;
      SELECT MAX(SEQ_NMBR) MAXNUMBER FROM DB2.A_PDC_TRNS WHERE TOKEN_ID = #{tokenID} AND RSLT_TYP = 10
  </code></pre>
  
  <p>
  In java code I am using this code to run above query-</p>
  
  <pre><code>Integer maxSeqNumber = getSqlSession().selectOne("getMaxSeqNumFromTrans", contributionsParam);
  </code></pre>
  
  <p>But this code returns null to me. I don't know what is going wrong here. Did I miss something? </p>