Mysql查询结果顺序按in()中ID的顺序排列的实例分析

<select id="queryGBStyleByIDs" resultMap="styleMap"> 
 select style_num_id ,style_id,style_title,style_pic FROM gb_style where online = 1 AND is_hide = 0 and style_num_id in 
 <foreach collection="styleNumIDs" item="styleNumId" separator="," open="(" close=")"> 
 #{styleNumId} 
 </foreach> 
 ORDER BY FIELD 
 <foreach collection="styleNumIDs" item="styleNumId" separator="," open="(style_num_id," close=")"> 
 #{styleNumId} 
 </foreach> 
 </select>

select style_num_id ,style_id,style_title,style_pic FROM gb_style where online = 1 AND is_hide = 0 and style_num_id in (1,3,2,5) 
order by field (style_num_id,1,3,2,5);