请教下 sqlserver 的这个 with 语法怎么转 mysql？

with A1 as (
        select * from sys_user a
        where a.user_id='U0001'
        UNION ALL
        select b.* from sys_user b inner join A1 c 
                on  c.LEADER_ID=b.user_ID and c.user_id<>c.LEADER_ID
)
SELECT user_id,user_code FROM A1
​

在 with 里有 A1。。这种怎么转 mysql？