title: mybatis return result map with duplicate entry
body: <p>I am using mybatis to retrieve data from DB, the data returned is containing duplicate entries.</p>
  
  <p>Required result : Column Name , Value </p>
  
  <p>Expected result is : column1 value A 
  But returned result is : COLUMN1 value A , column1 value A.</p>
  
  <p>Hope able to clarify my doubt.</p>
  
  <p>Can anybody tell me why it is happening? </p>
  
  <pre><code>&lt;select id="getContentMap" resultType="map" parameterType="map"&gt;
              select planId,location_qualifier  from disclaimer_disclosure_content where 
              &lt;choose&gt;
                  &lt;when test="plan_id != null"&gt;
                      plan_id = #{plan_id}
                  &lt;/when&gt;
                  &lt;when test="product_id != null"&gt;
                      product_id = #{product_id}
                  &lt;/when&gt;
                  &lt;otherwise&gt;
                      issuer_id = #{issuer_id}
                  &lt;/otherwise&gt;
              &lt;/choose&gt;
               and effective_date &gt;= #{effective_date} 
               and location_qualifier LIKE  CONCAT('%' , #{location_qualifier} , '%') 
          &lt;/select&gt;
  </code></pre>