解决mybatis批量更新(update foreach)失败的问题

 <!--批量更新报表 -->
 <update id="updateIssueByBatch" parameterType="java.util.List">
  <foreach collection="issueList" item="item" index="index" separator=";">
   update sys_issue
   <set>
    <if test="item.first != null and item.first != ''">first_class = #{item.first}, </if>
    <if test="item.second != null and item.second != ''">second_class = #{item.second}, </if>
    updated_time = now()
   </set>
   where id = #{item.Id} 
  </foreach>
 </update>

org.springframework.jdbc.BadSqlGrammarException:
### Error updating database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '......
### The error may involve .... 
### The error occurred while setting parameters ### SQL:

<!-- 批量更新 -->
 <update id="batchUpdate" parameterType="java.util.List">
  <foreach collection="list" item="item" separator=";">
   update xxxxxx
   <set>
    <if test="item.xxx!= null">
     xxx= #{item.xxx,jdbcType=BIGINT},
    </if>    
    ......    
   </set>
   where id =#{item.id}
  </foreach>
 </update>