MyBatis特殊字符转义

    <select id="selectByExampleExt" parameterType="com.cn21.redisCluster.model.AppInfoExampleExt" resultMap="BaseResultMapExt">
        SELECT temp.*,r.* from (
            SELECT a.* from appinfo as a where 1=1 
            <if test="appid != null and appid != ‘‘ ">
                and a.appid=#{appid,jdbcType=VARCHAR}
            </if>
            <if test="productid != null">
                and a.productid=#{productid,jdbcType=INTEGER}
            </if>
            ORDER BY a.lastupdatetime DESC
            <if test="limitStart&gt;=0 and limit&gt;0">   （这里就是类似的 <if test="limitStart>=0 and limit>0">）
                LIMIT ${limitStart} , ${limit}
            </if>
            <if test="limitStart==-1 and limit&gt;0">
                LIMIT ${limit}
            </if>
             ) temp,redisdb r where temp.appid = r.appid
    </select>