面試題：查詢所有上級SQL

 

[customer] 寫錯了，該寫bossone

 

求 User10 User20 User30 User60 的所有上級

 

select a.id,a.[User] ,a.customer as bossone,bosstwo = b.[customer]

,bossthree = c.customer from tem a

left join tem b on a.customer = b.[user]

left join tem c on b.customer = c.[user]

where a.[User] = 'user10' or a.[User] = 'user20' or a.[User] = 'user30' or a.[User] = 'user60'