表A:
StataionID time TT
Zh01 2011/12/23 20:00:00 11
Zh01 2011/12/23 19:00:00 12
Zh01 2011/12/23 18:00:00 13
Zh01 2011/12/23 17:00:00 14表B:
StataionID time XX
Zh01 2011/12/23 20:00:00 6.3
Zh01 2011/12/23 19:00:00 5.6
Zh01 2011/12/23 18:00:00 6.6
Zh01 2011/12/23 17:00:00 8.9请问写sql语句如何得到???
StataionID time TT XX
Zh01 2011/12/23 20:00:00 11 6.3
Zh01 2011/12/23 19:00:00 12 5.6
Zh01 2011/12/23 18:00:00 13 6.6
Zh01 2011/12/23 17:00:00 14 8.9
StataionID time TT
Zh01 2011/12/23 20:00:00 11
Zh01 2011/12/23 19:00:00 12
Zh01 2011/12/23 18:00:00 13
Zh01 2011/12/23 17:00:00 14表B:
StataionID time XX
Zh01 2011/12/23 20:00:00 6.3
Zh01 2011/12/23 19:00:00 5.6
Zh01 2011/12/23 18:00:00 6.6
Zh01 2011/12/23 17:00:00 8.9请问写sql语句如何得到???
StataionID time TT XX
Zh01 2011/12/23 20:00:00 11 6.3
Zh01 2011/12/23 19:00:00 12 5.6
Zh01 2011/12/23 18:00:00 13 6.6
Zh01 2011/12/23 17:00:00 14 8.9
from a
join b on a.StataionID=b.StataionID and a.time=b.time
能一直Join吗?
from 表A A inner join 表B B on A. StataionID=B.StataionID
from a
join b on a.StataionID=b.StataionID and a.time=b.time
笛卡尔积。
Inner Join
select a.StataionID, a.time, a.TT, b.XX
from a
join b on a.StataionID=b.StataionID and a.time=b.time
from a,b
where a.StataionID=b.StataionID and a.time=b.time
from a
join b on a.StataionID=b.StataionID and a.time=b.time