Mybatis的if从句中的赋值乌龙

String activityType = vo.getActivityType();
		String merchantId = vo.getMerchantId();
		List<TbMarketActivity> activity = activityMapper.getActivityByMerchantId(activityType, merchantId);

<select id="getActivityByMerchantId"
            resultType="cn.buyforyou.aipc.small.api.entity.marketActivity.TbMarketActivity">
        SELECT
        <include refid="tbMarketActivityColumns"/>,
        b.product_discount as "productDiscount"
        FROM
        tb_market_activity a
        left join tb_market_activity_product b on a.activity_id = b.activity_id
        <where>
            a.status = '2'
            and a.activity_type = #{activityType}
            and a.merchant_id = #{merchantId}
        </where>
        <if test="activityType != null and activityType = '2'.toString()">
			order by product_discount
		</if>
		limit 1
    </select>

 ==> Preparing: SELECT a.activity_id AS "activityId", b.product_discount as "productDiscount" FROM tb_market_activity a left join tb_market_activity_product b on a.activity_id = b.activity_id WHERE a.status = '2' and a.activity_type = ? and a.merchant_id = ? order by product_discount limit 1 
 ==> Parameters: 2(String), 3a9d21a0d18a4e1c819dac57b1730992(String)
 <==      Total: 0

<if test="sex=='Y'.toString()">
或者
<if test = 'sex== "Y"'>

<if test="sex=='Y'">