查詢最近七天的會員增加數量sql

<!--查詢最近七天的新增會員數量 -->
    <select id="findInsertUserSevenDayStatistical" resultType="InsertUserSevenDayStatistical">
        select
        a.time,(ifnull(b.count,0)) as count
        from (
        SELECT
        curdate() as time
        union all
        SELECT date_sub(curdate(), interval 1 day)
        as time
        union all
        SELECT date_sub(curdate(), interval 2 day) as time
        union all
        SELECT
        date_sub(curdate(), interval 3 day) as time
        union all
        SELECT
        date_sub(curdate(), interval 4 day) as time
        union all
        SELECT
        date_sub(curdate(), interval 5 day) as time
        union all
        SELECT
        date_sub(curdate(), interval 6 day) as time
        ) a

        left join (
        select
        date(register_time) as datetime, count(*) as count
        from
        car_user where
        register_time>DATE_ADD(NOW(),INTERVAL -7 DAY)
        group by
        date(register_time)
        ) b on a.time = b.datetime

        ORDER BY
        time ASC
    </select>