<sql id="selector">
        select * from account
</sql>

<!--根据性别和名称查询用户 where标签可以去掉第一个前and -->
    <select id="selectUserBySexAndUsername" parameterType="deep.pojo.Account"
        resultType="deep.pojo.Account">
        <include refid="selector"/>
        <where>
            <if test="sex != null and sex != ‘‘ ">
                sex = #{sex}
            </if>
            <if test="username != null and username !=‘‘">
                and username = #{username}
            </if>
        </where>
    </select>