MyBatis动态sql之foreach标签 Mybatis之foreach标签使用方法，Mybatis之foreach标签在xml文件中使用方法，持久层写法：
<if test="questionIds!= null and questionIds.size()>0" >
WHERE id in
<foreach collection="questionIds" index="index" item="item" open="(" separator="," close=")">
#{item}
</foreach>
</if>
