ibatis 大於等於小於等於的寫法

在ibatis的sql語句xml配置文件中，寫sql語句會經常用到大於等於小於等於等等符號。網上搜羅了一些寫法，大致有3種：

1. 其實就是xml特殊符號，轉義的方式。 
   < < 
   > > 
   <> <> 
   & & 
   ' ’ 
   " ” 
   比如： 
   select (case when (UNIX_TIMESTAMP(now())-UNIX_TIMESTAMP(ur.offline_time)-5*60*1000)>0 then '1' else '0' end) as offline_flag from ……

2. 使用<![CDATA[ sql語句]]>符號進行說明，將此類符號不進行解析 。 
   比如： 
   <isEqual property="offline_flag" compareValue="0"> 
and <![CDATA[((UNIX_TIMESTAMP(now())-UNIX_TIMESTAMP(ur.offline_time)-5*60*1000)<=0 or u.record_id=0)]]> 
</isEqual>

3. 如果是參數字段，可以用ibatis的語法。 
   <isEqual> 相等。 
<isNotEqual> 不等。 
<isGreaterThan> 大於 
<isGreaterEqual> 大於等於 
<isLessThan> 小於 
<isLessEqual> 小於等於 
   比如： 
   <isNotEmpty prepend="AND" property="username"> 
u.username like '%$username$%' 
</isNotEmpty> 
<isNotEmpty prepend="AND" property="location"> 
concat(u.country,u.province,u.city) like '%$location$%' 
</isNotEmpty> 
<isEqual property="offline_flag" compareValue="1"> 
and (UNIX_TIMESTAMP(now())-UNIX_TIMESTAMP(ur.offline_time)-5*60*1000)&gt;0 
</isEqual> 
<isEqual property="offline_flag" compareValue="0"> 
and <![CDATA[((UNIX_TIMESTAMP(now())-UNIX_TIMESTAMP(ur.offline_time)-5*60*1000)<=0 or u.record_id=0)]]> 
</isEqual> 
<!-- sort --> 
<isEqual property="sort_onlinetime" compareValue="asc"> 
order by u.online_time asc 
</isEqual> 
<isEqual property="sort_onlinetime" compareValue="desc"> 
order by u.online_time desc 
</isEqual> 
<isEqual property="sort_registtime" compareValue="asc"> 
order by u.register_time asc 
</isEqual> 
<isEqual property="sort_registtime" compareValue="desc"> 
order by u.register_time desc 
</isEqual> 
<isEqual property="sort_appversion" compareValue="asc"> 
order by u.app_version asc 
</isEqual> 
<isEqual property="sort_appversion" compareValue="desc"> 
order by u.app_version desc 
</isEqual>