14-票价问题

create table person(
name string,
station string
)
row format delimited fields terminated by '\t'
lines terminated by '\n'
stored as textfile;
load data local inpath 'person.txt' into table person;

create table ticket(
station string,
money string
)
row format delimited fields terminated by '\t'
lines terminated by '\n'
stored as textfile;
load data local inpath 'ticket.txt' into table ticket;


条件过滤语句
case when xxx else xxxx end

问题1：按照站数算对应价格
select p.name,p.station,t.money
from person p,ticket t where p.station=t.station


问题2：10站以上打8折

case when condition then operation else operation end

select p.name,p.station,case when p.station>10 then t.money*0.8 else t.money end
from person p,ticket t where p.station=t.station


select p.name,case when t.station>10 then t.money*0.8 else t.money end
from person p,ticket t
where p.station = t.station

问题3：10-15站打9折、15站以上打8折

select p.name,p.station,case when p.station>10 then (case when p.station>15 then t.money*0.8 else t.money*0.9 end)  else t.money end
from person p,ticket t where p.station=t.station

select p.name,case when t.station>10 then (case when t.station>15 then t.money*0.8 else t.money*0.9 end) else t.money end
from person p,ticket t
where p.station = t.station

1 5
2 5
3 5
4 5
5 5
6 5
7 5
8 5
9 5
10 10
11 10
12 10
13 10
14 10
15 10
16 10
17 10
18 30
19 30
20 30
21 30
22 30
23 30
24 30
25 30
26 30
27 30
28 30
29 30
30 30
31 30
32 30
33 30
34 30
35 30
36 30
37 30
38 30
39 30
40 30

huang 26
lili 25
dongdong 13
wangxiao 5