MyBatis XML去除多余AND|OR前缀或逗号等后缀的操作

select * from user 
<trim prefix="WHERE" prefixOverride="AND |OR">
<if test="userName != null and userName.length()>0"> AND user_name=#{userName}</if>
<if test="loginName != null and loginName.length()>0"> AND login_name=#{loginName}</if>
</trim>

select * from user where login_name = 'xx'

update user
<trim prefix="set" suffixOverride="," suffix=" where user_id = #{userId} ">
<if test="userName != null and userName.length()>0"> user_name=#{userName} , </if>
<if test="loginName != null and loginName.length()>0"> login_name=#{loginName} , </if>
</trim>

update user set login_name='xx'  where user_id='xx'

<select id="selectBySelective" resultType="xxx.UserInfo">
select
<include refid="Base_Column_List" />
from uc_user
<trim prefix="WHERE (" suffix=")" prefixOverrides="AND |OR ">
<if test="userName != null" >
user_name = #{userName}
</if>
<if test="email != null" >
or email = #{email}
</if>
<if test="phone != null" >
or phone = #{phone}
</if>
<if test="weiboId != null" >
or weibo_id = #{weiboId}
</if>
<if test="wxId != null" >
or wx_id = #{wxId}
</if> 
<if test="qqId != null" >
or qq_id = #{qqId}
</if>
</trim>
and status = 1
</select>