上传者: 42202724
|
上传时间: 2022-04-29 15:42:10
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文件大小: 2.67MB
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文件类型: PPT
从Datalog到SQL3
SQL3:
with recusive Reaches(destination,departs) as
(select destination,departs from Flight)
union
(select R1.destination,R2.departs
from Reaches as R1, Reaches as R2
where R1.departs=R2.destination)
select * from Reaches;